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Home My WebLink About58 Development Permit 350 Southwood Valley Section 24A02/13/97 10:43 GARRETT ENGINEERING ~ 409 764 3496 1)02 LAYBACK CURB DETAILS -Longitudinal . L 1.4-r-r -#4 Bors l_ ---24·------i PC ·5 PC6 " rzY2 11 I ~II ! R\ i 9" I r . , ... • \j r . 1 -~r· r. •"-'I 1-s· TI a 'h. ..,.-+. ;. 'T s" 7 'Ii' l I.,,\.._ I""" ,. _/ 3'' 1 · 4 Lonqitudinal ~ " 18 c-c ~ ~--·--24 11 I 2· CITY STANDARD . · 3;4 ·· R : . '" ~ ~ .a:.--· --<1 <1 ... .... .... , 10:43 GARRETT ENGINEERING ~ 409 764 3496 ~01 TRANSMITTAL NUMBER OF PAGES (INCLUDING COVER SHEET) ___ ?-___ _ ..................................................................... GARRE'IT ENGINEERING ..................................................................... PLEASE KEEP nlis INFORMATION CONFIDENTIAL mu COMMENTS OR SPECIAL INSTRUCI'IONS: II tDt/ of.' fk /;;(~-M~ CJ~ 7i/A-r /S J51)c:. (J (_ ~Jrs CoJf.tl 1J s_J J. 1. 2. 3 . 4. 5 . 6. 7. 8. 9. 10. Engineer's Estimate For Street, Drainage, Water, & Sanitary Sewer Im To Tract "B", Block 55 APPROV DFOR Southwood Valley-Section 24A ----;;;...;~:...=.-=-~.:.:..:....J College Station, Brazos County, Texas March, 1995 1 1/2 " Hot Mix Asphaltic Concrete 1322 S.Y. $3.75 $ 4 ,957.50 Surface T e 11 0 11 6" Thickness Compacted Crushed 1380 S.Y. $ 5 .80 $ 8,004.00 Limestone Base 6" Thickness Compacted Lime 1594 S.Y . $3.00 $ 4 ,782.00 Stabilized Sub rade Assume 5% 24" Reinforced Concrete Curb & 754 L.F. $ 6.50 $ 4 ,901 .00 Gutter Reinforced Concrete Valle Gutter 575 S.F. $ 2.50 $ 1,437.50 6" Reinforced Concrete Mono . Curb 79 L.F. $4.50 $ 355.50 Reinforced Concrete Outlet Control 1 Ea . $1,600.00 $1 ,600 .00 Structure Reinforced Concrete Pilot Channel 703 S .F. $ 2 .50 $1 ,757.50 Roadwa Excavation 972 C .Y . $ 3.50 $ 3,402.00 4" Thick Reinforced Concrete Ri -Ra 223 S.F. $ 2 .50 $ 557.50 Total Amount Of Cost For Street & Drainage Improvements: $ 31,754.50 Wt I • t Engineer's Estimate For Street, Drainage, Water, & Sanitary Sewer Improvements To Tract "B", Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas March, 1995 (Continued) rn1n'1: ~ .......... ·--- J~P: ~(111; ~. l)ifG f."tii't-JTTil> ~ .... ,...,, ____ ,,......,.. __ ,,,J.t.oii...0•-As.u•-'·"---.. ~~~.J~,_,;,.,.,.J.~'"""' .... -.... - 1. 6" Diameter C900 -Class 200 P.V.C. 36 L.F. $ 15 .00 $ 540 .00 Water Line (0 - 5 feet) 2. 6" Diameter C900 -Class 200 P.V.C. 97 L.F . $16.00 $1 ,552 .00 Water Line (5 - 7 feet) 3. 6" Diameter C900 -Class 200 P.V.C . 199 L.F . $17.00 $ 3 ,383 .00 Water Line (7 -9 feet) 4. 1 1/2" Diameter Type "K" Copper 172 L.F . $14.00 $ 2,408 .00 Water Service Line 5. 6" X 1 1/2" Bronze Service Saddle w/1 5 Ea. $ 250 .00 $1 ,250.00 1/2" Corp. Stop , 1 1 /2" X 1" X 1" Wye and 2-1" Stops @ End 6. 6" Plug w/blow-off Assembly 1 Ea . $ 350 .00 $ 350 .00 7. Standard City Of College Station 1 Ea . $1,400.00 $ 1,400.00 Fire Hydrant w/appurtenances 8. Trench Safety 1 L.S. $ 494 .00 $ 494 .00 Total Amount of Cost For Water Improvements: $11 ,377.00 - Engineer's Estimate For Street, Drainage, Water, & Sanitary Sewer Improvements To Tract "B", Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas March, 1995 (Continued) s "t s I t m:ttt1[ 1~1 , l~h ~~ .~f:t~liinrr.·~·: ~L~·-······~·-·~·I·~ ~-...,--~ .... -.......ll,J,~ .. ~....ii A.J~ ....... uJ ..... 1. 6" Diameter SDR. 26-3034 P.V.C . 110 L.F . $ 15 .00 San. Swr . Line (0-5 feet) 2. 6" Diameter SDR. 26-3034 P.V.C . 296 L.F . $16.00 San. Swr. Line (5-7 feet) 3. 4" Diameter Schedule 40 San . Swr. 198 L.F . $ 14 .00 Service Line 4. Standard Manhole (0 - 8 feet) 3 Ea . $1 ,000 .00 5. 4"X4 "X4 " Wye w/2 -4" Pluqs 5 Ea . $ 225 .00 6 . 6"X4" M .J . Tee 4 Ea . $ 250 .00 7 . Trench Safety 1 L.S $ 592.50 Total Amount Of Cost For Sanitary Sewer Improvements: Summary Street and Drainage Improvements : Water Improvements: Sanitary Sewer Improvements : Total: ~· ... .............. ...-.4" ............... ~ .. ,.. $1 ,650.00 $ 4 ,736 .00 $ 2 ,772 .00 $ 3 ,000 .00 $ 1,125.00 $1 ,000 .00 $ 592.50 $14,875 .50 $ 31 ,754.50 $11 ,377.00 $14,875.50 $ 58,007.00 ,.,.~.,.,.,.,.,.,.,.,.,., .. \"\• ·l ·I ·,. I · J •I· I• I •I · I· I• I• J ·I• I· I• I ..... ,., .,.,.,.,.,.,.,., .... ,., .... , .... ·I ·l·l·l·l•f •f·/ ·l·l·l·l·l·l·l·l·l·l·l ·l·I .,.,., ....... ,.,., .... ,.,., .... ,.,.,.,.,.,.,.,.,. 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Comme nts: the f-lc,-c is We need __,pk--l_A_l"l _? _t11J_l _vt_b_e_V"l __ h_, f_d_; YJ-=>--~---1...-p1_' ck-_-_urL· _ ~~ ,., ........ , .. , ................ ,.,,.,.,. •/ •l ·.'·l ·f·I ·I· I·/· l ·l·/•f •/•l•l•I ., . ,., . ' ..... ' .... , . '.' ., . ,., . ,. '.,. \•\. •I• I ·I •I· I ·I· I·.' ·I• I ·I•/•/·/• l •l •l•l •/•l •I . \•\·\. \· \.'. \• \. \• \ •\· \ •\. \•\. \• ,.,.,., •\• '. I •/ •I· I · I ·I· I ·I ·I ·I · I · I· I· I ·I ·!·I ·I · f •l •/•I •I · l·I \·\. \•' •\. \· \ •\. \ ·\. \• \. \· \ •\. \•\ •\• \•\ •\•\. \• '•\• \• •/ •/•/•I •I •I • l ·l ·I ·I •/• I ·/ ·I•/ •l•l•l •/•/ •/ •l•f •I •/ •I · I ,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,., .. ,.,.,.,.,.,.,.,. •f • / •f •/•I •I • I•/• I •/ •l•l•f • l •l •I • I •I • l •l •l • l •l • /•/ •/ • l •I • / ,., . \• \•\. ,., .,. '., .,.,. \.'. \. ,., •\•' .,. \•\. \• \•\. ,., •\• \ •\• ~~~:~~~:~:~~~'.~'.~~~:~:~:~:~~~~~:~:~:~:~:~:~:~:~:~:~:~:~:~~~'.~'.,':\.. ' (409) 764 -3570 (409) 764-349 6 FAX -VP. i .,.,., .. '.' ., . '.'. ,. ,., . ,., . ,. ,. •/•/·/• f·l •/•I ·l·l·l •l·l·/•l•l •I• .,. ,., . \•\. ,. '.,.' ., ., . ,., . ,., . ,.,.,.' ·l •l ·l·l ·l ·l·l "'·I ·!·l ·l·l·l ·l·l·l •l•l·I · •\•\•\•\•\•\•\•'\•\•\ .,., •\•\<'\•\·\•\· ,., •\•\•\ •I •l •l ·I ·l·l ·I· I ·I· I · I ·I · I ·I · I · I ·I·/•/•/• I•/• /·I· . \•\. \•\•\• ,., .. \•\. \• \ •\. ,., .,. ,., . ,., . ,. '.,. ,. ,.,. ,. •I •/ •I •/•/•/ •/•I •/ •I·/• I •I •/• J •I ·I·/•/• I·/•/•/ •I• l•J •I ., • \<'\•\• '"' •\•\•\• \•\. \O\•\. ,., .,. '•\. \•\ •\• ,., • \•\ •\•\• •/• l •l ·l·l ·I· l·l · l ·l ·J • J•/ •I •/•/• l ·l ·l•l ·I •I •I •l·l·l· I •I •I '. ,. '.,. '"'. ,., .,. '.,. ,., . ,. ,., . ,., ., . ,., . ,., . ,. ,., .. ,., .,. ,. •I•/•/• I ·I ·I· I •I• I •I •I • I •I • I ·I · I •I •I• I ·I •/• I•/ •I •I•/•/ •I •I •/ •I . ,., ...... ,., ., .,., .,,., •\• , .. ,. \•\. ,. '•\. \•'. '. ,., . \•' .,., ., .,., .,. '. ... Figure XII Development Permit City of College Station , Texas Si t e Legal Desc ri ption : Tgt1(r ''s", Bl.OlK 56 Sountwba!? VAU.E'(-S@iW /}lA ~owr-£ ~05/AS£ ftl} Site O w ner: -riif>Mf\S' PD.bPEeflfS Archit e ct/ Engineer: Q.ARRfJT bv G-1 N (fg iN9 Date Application Filed : _______ _ Addres s : f6. &'ll 10 l6ln ~ue:iE ~loN ll~LtO T elep hone :(4b1}-J/o4-(D~Lf Ad dr ess : '11./J/l/ CARrQ Cm PKWb S'u1T! I~ BfYArJ T ele phone N o : {4rA}-f4(p -U,Sf3 Address : ------------ Telephone N o : ---------- Application is hereby made for the following development specific waterway alterations : ~lm~Ef fRt\~ 2.~ tars WIU-fl.Aw lt\Th 11-f( ~&~ 1>\'.:.i'(N'f lOlJ Pmp ON Lor \0 /\NJ> Bt RafASeJ 11(~ 71/f fX1~1)H9 C.O t<CRC!¢ fWIJ!f A.LONS 111~ NtJb'H 511£ a,: 11-lf f/il,Plfl{tY. JJK DG1fHrl/JN /)Ot(p WILL lll<W/2f ~ !Aw fLOvJ CHANrJB., AND AN ()t!n.rr QlN!i'.lL 5fffKfuff D D D D D As a condition of approval of this permit application , I agree to construct the improv ements proposed in this application according to these documents and the requirements of Chapter 13 o f c liege Station ·!Y Code. Contractor ! . ...... DRAINAGE COMPUTATIONS For A Replat Of Tract 11 8 11 , Block 55 Southwood Valley -Section 24A College Station , Brazos County, Texas Prepared By: Garrett Engineer ing 4444 Carter Creek Parkway -Suite 108 Bryan, Texas 77802 Telephone : (409) 846 -2688 ~· TABLE OF CONTENTS . s . . ... Drainage Report ummary ................................................................................................. 1-m Pre-Development Discharge Rate Calculations ...................................................................... 1 Post-Development Discharge Rate Calculations (for comparison only) ................................... 2 Free-Flow Discharge Rate Calculations ................................................................................. 3 Calculations of Flow Into Pond .............................................................................................. 4 Inflow Hydrograph Ordinates ............................................................................................. 5-8 Pre-and Post-Development Hydrographs (without pond) ................................................ 9-11 Detention Pond Characteristics ....................................................................................... 12-14 Inflow/Outflow Simulations ............................................................................................ 15-26 Pre-and Post-Development Hydrographs (with detention pond) .................................... 27-32 Storm Simulation Summary ................ : ................................................................................ 33 DRAINAGE COMPUTATIONS For A Replat of Tract "B", Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas * November, 1994 * SUMMARY The project is situated adjacent to Welsh Ave., and south of San Mario Ct. in Southwood Valley, College Station, Brazos County, Texas. Tract "B", Block 55 of Southwood Valley -Section 24A consists of 15 lots, these 15 lots being established within the bounds of a 3.93 acre tract. The total drainage area tributary to the project is 3.93 acres. The pre-development run-off coefficient was estimated to be 0.40, while taking into account typical residential site improvements would result in a post- development run-off coefficient of 0.56. A detention facility will be constructed in the northwest comer of the property as designated on the plat. The detention pond is designed to facilitate up to and including the 100-year storm event, and discharge at a rate less than the current pre-development peak discharge rate. The detention pond will intercept, store and meter run-off from 2.50 acres of the project. The run-off generated on the remaining 1.43 acres will "free-flow" across the project site unmetered off the property. From the computations on page 1, based on the total tributary drainage area of the project being estimated at 3.93 acres, the pre-development run-off coefficient being assumed at 0.40, and a minimum time of concentration of 10 minutes, the relative pre-development peak discharge rate ("Q") was determined. The Rational Method was utilized to compute the estimated peak pre-development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA. "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off coefficient, assumed to be 0.40 in the pre-development condition, "I" is the storm intensity in inches per hour, and "A" is the area of the drainage basin in acres. From the computations on page 2, based on the tributary area of 3.93 acres, the post-development run-off coefficient being assumed at 0.56, an<;l a minimum time of concentration of 10 minutes, the relative pre- development peak discharge rate ("Q") was determined assuming the same minimum time of concentration of 10 minutes . The Rational Method was again utilized to compute the estimated peak post-development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA, where; "Q" is the peak discharge rate in cubic feet per second. "C" is the run-off coefficient, in the post-development condition "C" is assumed to be 0.56, "I" is the storm intensity in inches per hour and "A" is the area of the basin in acres. The comparison between the peak pre-development diScharge rate and post-development discharge rate is included as an aid to the designer to · establish a preliminary "target" for the necessary volwne in the proposed detention facility. This preliminary estimate is found by simply determining the volwne generated from the difference between the pre-development and post-development hydrographs (see pages 9-q for pre- development and post-development hydrographs). Please note that the post-development hydrograph shown on these same graphs assumes no detention. Page 3 and page 4 provide computations that determine the post-development run-off that is not routed through the detention facility ("free-flow") and post-development run-off that is routed through the detention facility. Page 5 and page 6 are tabulations of the pre-development hydrograph and the post-development hydrograph based on the computations performed on page 1 and page 2. The post-development hydrograph assumes no detention to facilitate direct comparison in the pre-and post-development conditions; Page 7 and page 8 are tabulations of the post-development hydrograph for run-off directed through the detention facility and the post-development hydrograph for "free-flow" from the project site .. Computations on page 4 determine the actual peak post-development "inflow" rate supplied to the proposed detention facility . From this "inflow" rate and the time of concentration (10 minutes minimum), a hydrograph as tabulated on page 8 can be derived. The hydrograph is triangular in shape and is based on the standard SCS unit hydrograph with time to peak set equal to the time of concentration and the total time base set at 3.00 times the time of concentration. Please note that a 30 minute total storm event duration was utilized exclusively throughout this report due totally to the small physical size of the project Having derived the preliminary volume requirements and "allowable peak" discharge rate, it is now possible to design the final detention facility and outlet control structure. Page 12 presents a tabulation and a depth versus volwne graph of the detention facility. The maximum depth of the pond was set at 1.75' (top retaining wall less flow line "out" of outlet control structure: 286.75' -285.00' = 1.75'). Page 13 supplies a tabulation and a rating curve for the proposed outlet control structure. A rectangular weir was decided upon due to depth verses discharge ratio characteristics associated with the anticipated shallow headwater depth (maximum of 1.75') and the fixed weir width of 2.00'. The equation used to determine discharge was Q = CLH3/2 where "Q " is the discharge rate in cubic feet per second . "C" is the coefficient of discharge, in this case assumed to be set at 3.000. "L" is the width of the weir in feet, in this case assumed to be set at 2.00'. "H" is the headwater depth in feet (ranges from O' to a maximum of 1.75'). Page 14 presents a tabulation of the relationship between discharge from the detention facility and the dimensionless quantity 2S/t-O. Also presented is a Storage Indication Curve for the detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrograph, and rating curve for the outlet structure. The storage indication curve as shown on page 14 is a graphical solution to the equation presented in the "Drajna2e Policy And Desi2n Standards " as follows: 2s 1 (I 1+12) + (----------------01) dt 2s 2 = (-----------------+ ov dt Page 15 through page 26 present simulations of the 2, 5, 10, 25, 50, and 100 year storm events. The first page of each storm simulation represents the tabulated data for the storm event. The maximum depth achieved in the detention pond during each simulation is shown below as is the time period during which this maximum depth occurs after the beginning of the storm event The calculated peak discharge rate corresponding to this depth over same period is also shown below. Additionally, the maximum water surface elevation achieved during each event and the maximum peak discharge during each event are listed below. The second page of each storm simulation represents the pre-development hydrograph, the post-development hydrograph (with no detention), the post-development hydrograph as routed through the detention pond, and post-development "free-flow" hydrograph for each storm event ii Storm (Year) Max Depth (Ft) 2-year 0.99 5-year 1.13 10-year 1.22 25-year 1.33 50-year 1.44 100-year 1.48 Time Period (Min) 16-17 16-17 16-17 16-17 16-17 16-17 Max Discharge Max Elev (CFS) (Ft MSL) 5.91 7.17 8.04 9.17 10.36 10.81 285.99 286.13 286.22 286.33 286.44 286.48 Max Velocity (Ft/Sec) 2.99 3.18 3.31 3.46 3.60 3.65 Page 27 through page 32 provide total inflow/outflow hydrographs for the 2, 5, 10, 25, 50 and 100-year pre- development and post-development storm events. It can be determined from these same hydrographs that the post-development peak discharge rates have been minutely decreased from those peak pre-development discharge rates due to the incorporation of the detention facility in the post-development condition. Page 33 is a graphical representation and tabulation of the detention pond storage volumes as a percent of the maximum volume of the detention pond. Ideally, the amount of water stored in the detention pond should be at or below 90% of the capacity of the detention pond. Total post-development peak discharge rates from the detention pond outlet control structure and project site are kept less than the pre-development peak discharge rates due to the incorporation of the proposed detention facilities. Subsequent peak post-development discharge velocities projected to be within manageable limits. iii Tributary Area(" A"): 3.93 Acres Pervious Area : 3.93 Acres Impervious Area : 0.00 Acres Run-Off Coefficient ("Cwt"): 0.40 Time Of Concentration ("T/c"): Woodlands: Low Elevation: High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vw"): Time: Pastures: Low Elevation: High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vp"): Time : Pavements: Low Elevation: High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vpave"): Time : Total Travel Time: Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 10.03 5-Year: 12.19 10-Year: 13.69 25-Year: 15.63 50-Year: 17.67 100-Year: 18.45 1 C= 0.40 C= 0.98 0.00 0.00 0.00 0 .00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 10.00 Minutes Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determine Post-development Peak Storm Water Dischar e No Detention Tributary Area ("A"): 3.93 Acres Pervious Area : 2.84 Acres c = 0.40 C= 0.98 Impervious Area: 1.09 Acres Run-Off Coefficient ("Cwt"): 0.56 Time Of Concentration ("T/c "): 1 O Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches I Hour 5-Year: 7 .69 Inches I Hour 10-Year: 8.63 Inches I Hour 25-Year: 9.86 Inches I Hour 50-Year: 11.15 Inches I Hour 100-Year: 11.64 Inches I Hour Peak Discharge Rate ("Q "): 2-Year: 14.06 Cubic Feet I Second 5-Year: 17.10 Cubic Feet I Second 10-Year: 19.19 Cubic Feet I Second 25-Year: 21.92 Cubic Feet I Second 50-Year: 24.78 Cubic Feet I Second 100-Year: 25.87 Cubic Feet I Second Comparison Of Predevelopment And Post-develo ment Peak Dischar e Rates Predevelopment Post-Development Increase 2-Year: 10 .03 Ft3/sec 14.06 Ft3/sec 4.03 Ft3/sec 5-Year: 12.19 Ft3/sec 17.10 Ft3/sec 4 .90 Ft3/sec 10-Year: 13 .69 Ft3/sec 19.19 Ft3/sec 5 .50 Ft3/sec 25-Year: 15.63 Ft3/sec 21.92 Ft3/sec 6.29 Ft3/sec 50-Year: 17.67 Ft3/sec 24.78 Ft3/sec 7 .11 Ft3/sec 100-Year: 18.45 Ft3/sec 25 .87 Ft3/sec 7.42 Ft3/sec Preliminary Determination Of Detention Pond Volume 2-Year: 4.03 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 3 ,630 Cubic Feet 5-Year: 4 .90 Ft3/sec x (30 Min. x 60 Sec . I 2 ) = 4,414 Cubic Feet 10-Year: 5 .50 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 4,954 Cubic Feet 25-Year: 6.29 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 5,658 Cubic Feet 50-Year: 7 .11 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 6,396 Cubic Feet 100-Year: 7.42 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 6,678 Cubic Feet 2 Determine Post-Development "Free-Flow" Peak Storm Water Dischar Tributary Area ("A"): 1.43 Acres Pervious Area : 1.00 Acres Impervious Area : 0.43 Acres Run-Off Coefficient ("Cwt"): 0.57 Time Of Concentration ("T/c"): 10 Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11 .64 Peak Discharge Rate ("Q"): 2-Year: 5.24 5-Year: 6.37 10-Year: 7.15 25-Year: 8.17 50-Year: 9.23 100-Year: 9.64 3 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determine Post-Development Flow Into Detention Pond = .. _i Tributary Area ("A"): 2.50 Acres Pervious Area : 1.84 Acres Impervious Area : 0.66 Acres Run-Off Coefficient ("Cwt"): 0.55 Time Of Concentration ("T/c "): 1 O Minutes (Min) Hourly Intensity Rates ("I "): 2-Year: 6.33 5-Year: 7 .69 10-Year: 8.63 25-Year: 9 .86 50-Year: 11 .15 100-Year: 11 .64 Peak Discharge Rate ("Q "): 2-Year: 8.82 5-Year: 10.73 10-Year: 12 .04 25 -Year: 13.75 50-Year: 15.54 100-Year: 16 .23 4 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Pre-Development Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year {Minutes} Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 1.00 1.22 1.37 1.56 1.77 1.84 2 2.01 2.44 2.74 3.13 3.53 3.69 3 3.01 3.66 4.11 4.69 5.30 5.53 4 4.01 4.88 5.47 6.25 7.07 7.38 5 5.01 6.10 6.84 7.82 8.84 9.22 6 6.02 7.32 8.21 9.38 10.60 11.07 7 7.02 8.54 9.58 10.94 12.37 12.91 8 8.02 9.76 10.95 12.51 14.14 14.76 9 9.03 10.97 12.32 14.07 15.90 16.60 ' --Peak=> 10 10.03 12.19 13.69 15.63 17.67 18.45 11 9.53 11.58 13.00 14.85 16.79 17.53 12 9.03 10.97 12.32 14.07 15.90 16.60 13 8.52 10.36 11.63 13.29 15.02 15.68 14 8.02 9.76 10.95 12.51 14.14 14.76 15 7.52 9.15 10.26 11.72 13.25 13.84 16 7.02 8.54 9.58 10.94 12.37 12.91 17 6.52 7.93 8.90 10.16 11.49 11.99 18 6.02 7.32 8.21 9.38 10.60 11.07 19 5.52 6.71 7.53 8.60 9.72 10.15 20 5.01 6.10 6.84 7.82 8.84 9.22 21 4.51 5.49 6.16 7.03 7.95 8.30 22 4.01 4.88 5.47 6.25 7.07 7.38 23 3.51 4.27 4.79 5.47 6.18 6.46 24 3.01 3.66 4.11 4.69 5.30 5.53 25 2.51 3.05 3.42 3.91 4.42 4.61 26 2.01 2.44 2.74 3.13 3.53 3.69 27 1.50 1.83 2.05 2.34 2.65 2.77 28 1.00 1.22 1.37 1.56 1.77 1.84 29 0.50 0.61 0.68 0.78 0.88 0.92 30 0.00 0.00 0.00 0.00 0.00 0.00 5 Post-Development Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0 .00 0 .00 0.00 0.00 0.00 0 .00 1 1.41 1.71 1.92 2.19 2.48 2 .59 2 2.81 3.42 3 .84 4.38 4 .96 5.17 3 4 .22 5.13 5.76 6.58 7.43 7 .76 4 5.62 6.84 7.68 8.77 9.91 10.35 5 7 .03 8.55 9.60 10.96 12 .39 12.93 6 8.44 10.26 11.51 13.15 14.87 15.52 7 9.84 11.97 13.43 15.34 17.34 18 .11 8 11.25 13 .68 15.35 17.53 19.82 20.70 9 12 .65 15 .39 17.27 19.73 22.30 23.28 Peak=> 10 14.06 17.10 19.19 21.92 24.78 25.87 11 13 .36 16 .24 18.23 20 .82 23.54 24 .58 12 12 .65 15 .39 17.27 19.73 22.30 23.28 13 11 .95 14 .53 16.31 18.63 21.06 21 .99 14 11.25 13 .68 15.35 17.53 19.82 20.70 15 10 .55 12 .82 14.39 16.44 18.58 19.40 16 9 .84 11 .97 13.43 15 .34 17.34 18.11 17 9.14 11.11 12.47 14.25 16.10 16.81 18 8.44 10 .26 11.51 13.15 14.87 15.52 19 7.73 9.40 10.55 12.05 13.63 14.23 20 7 .03 8.55 9 .60 10.96 12 .39 12.93 21 6.33 7 .69 8.64 9 .86 11 .15 11 .64 22 5 .62 6.84 7 .68 8.77 9 .91 10.35 23 4 .92 5 .98 6.72 7.67 8.67 9.05 24 4 .22 5.13 5.76 6.58 7.43 7 .76 25 3 .52 4.27 4.80 5.48 6.19 6.47 26 2.81 3.42 3.84 4.38 4 .96 5.17 27 2.11 2.56 2.88 3.29 3.72 3.88 28 1.41 1.71 1.92 2.19 2.48 2.59 29 0 .70 0 .85 0.96 1.10 1.24 1.29 30 0 .00 0.00 0.00 0.00 0 .00 0 .00 6 Post-Development "Free-Flow" Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.52 0.64 0.72 0.82 0.92 0.96 2 1.05 1.27 1.43 1.63 1.85 1.93 3 1.57 1.91 2.15 2.45 2.77 2.89 4 2.10 2.55 2.86 3.27 3.69 3.86 5 2.62 3.19 3.58 4.08 4.62 4.82 6 3.14 3.82 4.29 4.90 5.54 5.78 7 3.67 4.46 5.01 5.72 6.46 6.75 8 4.19 5.10 5.72 6.53 7.39 7.71 9 4.72 5.73 6.44 7.35 8.31 8.68 Peak=> [ ~o ' 5'.°"24 6.37 7.15 8.17 9.23 9.64 -11 4.98 6.05 6.79 7.76 8.77 9.16 12 4.72 5.73 6.44 7.35 8.31 8.68 13 4.45 5.42 6.08 6.94 7.85 8.19 14 4.19 5.10 5.72 6.53 7.39 7.71 15 3.93 4.78 5.36 6.13 6.92 7.23 16 3.67 4.46 5.01 5.72 6.46 6.75 17 3.41 4.14 4.65 5.31 6.00 6.27 18 3.14 3.82 4.29 4.90 5.54 5.78 19 2.88 3.50 3.93 4.49 5.08 5.30 20 2.62 3.19 3.58 4.08 4.62 4.82 21 2.36 2.87 3.22 3.68 4.15 4.34 22 2.10 2.55 2.86 3.27 3.69 3.86 23 1.83 2.23 2.50 2.86 3.23 3.37 24 1.57 1.91 2.15 2.45 2.77 2.89 25 1.31 1.59 1.79 2.04 2.31 2.41 26 1.05 1.27 1.43 1.63 1.85 1.93 27 0.79 0.96 1.07 1.23 1.38 1.45 28 0.52 0.64 0.72 0.82 0.92 0.96 29 0.26 0.32 0.36 0.41 0.46 0.48 30 0.00 0.00 0.00 0.00 0.00 0.00 7 Post-Development Flow Routed Through Detention Pond Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 0.88 1.07 1.20 1.38 1.55 1.62 2 1.76 2.15 2.41 2.75 3.11 3.25 3 2.65 3.22 3.61 4.13 4.66 4.87 4 3.53 4.29 4.82 5.50 6.22 6.49 5 4.41 5.36 6.02 6.88 7.77 8.11 6 5.29 6.44 7.22 8.25 9.33 9.74 7 6.17 7.51 8.43 9.63 10.88 11.36 8 7.06 8.58 9.63 11.00 12.43 12.98 9 7.94 9.65 10.84 12.38 13.99 14.61 Peak=> r 10 8.82 10.73 12.04 13 .. 75 15.54 16.23 11 8.38 10.19 11.44 13.06 14.77 15.42 12 7.94 9.65 10.84 12.38 13.99 14.61 13 7.50 9.12 10.23 11.69 13.21 13.79 14 7.06 8.58 9.63 11.00 12.43 12.98 15 6.62 8.04 9.03 10.31 11.66 12.17 16 6.17 7.51 8.43 9.63 10.88 11.36 17 5.73 6.97 7.83 8.94 10.10 10.55 18 5.29 6.44 7.22 8.25 9.33 9.74 19 4.85 5.90 6.62 7.56 8.55 8.93 20 4.41 5.36 6.02 6.88 7.77 8.11 21 3.97 4.83 5.42 6.19 6.99 7.30 22 3.53 4.29 4.82 5.50 6.22 6.49 23 3.09 3.75 4.21 4.81 5.44 5.68 24 2.65 3.22 3.61 4.13 4.66 4.87 25 2.21 2.68 3.01 3.44 3.89 4.06 26 1.76 2.15 2.41 2.75 3.11 3.25 27 1.32 1.61 1.81 2.06 2.33 2.43 28 0.88 1.07 1.20 1.38 1.55 1.62 29 0.44 0.54 0.60 0.69 0.78 0.81 30 0.00 0.00 0.00 0.00 0.00 0.00 8 16.00 14.00 ... Q) Q. -12.00 Q) Q) u.. 0 ........ 10.00 ·-"O ..0 c ::::J 0 8.00 (.) 0 ...._, Q) & Cl) 6.00 ... 0 .c 4.00 ~ Ci 2.00 0.00 18.00 ... 16 .00 Q) Q. a; 14.00 Q) 12.00 u.. 0 ........ ·-"O 10 .00 ..0 c ::::J 0 (.) 0 8.00 ...._, Q) &Cl) 6.00 ... 0 .c 4.00 0 I/) Ci 2.QO 0.00 0 Total Pre-Development Vs. Total Post-Development (No Dete ntion) Peak Discharge Rotes 2-Yeor Storm Event 5 10 15 20 25 Time (Minutes) Pre-Development Hydrograph Tota l Post-Development Hydrograph 0 Total Pre-D e ve lopment Vs . Total Post -Development (No Det e ntion) Peak Discharge Rotes 5-Yeor Storm Event 5 10 15 20 25 Time (Minutes) Pre -De v elopment Hydrograph 9 Post-Dev elopment Outflow Hydrograph Without Detention 30 30 20.00 ... 18 .00 Cl> 0.. 16.00 -$ 14.00 l,L. 0 ...... 12.00 ·-,, .Q c :I 0 10 .00 u 0 '"'~ 8.00 & ... 6.00 0 .r::. ~ 4.00 0 2.00 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 10-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pre -Dev elopment Hydrograph ---Post-Development Outflow Hydrograph Without Detention 25.00 ... Cl> 0.. 20.00 l l,L. 0 ...... 15 .00 ·-,, .Q c :I 0 ~~ 10.00 Cl> Cl) O> ... 0 .r::. ~ 5.00 0 0.00 0 Total Pre-Dev e lopm e nt Vs. Total Post -Development (No Detention) Peak Discharge Rates 25-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pre-Development Hydrograph ---Post-Dev elopment Outflow Hydrograph Without Detention 10 25 .00 .... G> Q.. 20.00 -G> G> u. 0 ...... 15.00 ·-"O ..0 c :J 0 0 0 ;~ 10 .00 O> .... 0 .l: ~ 5.00 a 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 50-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pre-Development Hydrograph ---Post-Developme nt Outflow Hydrograph Without Detention 30 .00 .... G> 25 .00 Q.. 'i G> 20 .00 u. 0 ...... ·-"O ..0 c :J 0 15.00 ~~ G> Cl) 0) 10.00 .... 0 .l: .~ 0 5.00 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 100-Year Storm Event 5 10 15 20 25 Time (Minutes) Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detentio.n 11 30 Detention Pond De th Vs. Volume Elevation Depth Volume (Feet) (Ft3) 285 .00 0 .00 0 285 .22 0 .22 40 285.47 0.47 490 286.00 1.00 2,361 286 .50 1.50 4 ,616 286.75 1.75 5 ,867 Detention Pond Depth Vs. Volume l.80 1.60 1.40 i 1.00 ....... ~~~-+-~~~-t--#"~~t--~~-----,r--~~----t~~~----j ... .....,, ~ ~ 0 .80 0.60 0 .40 0 .20 0 .00 0 1,000 2 ,000 3,000 4,000 5,000 6,000 Detention Pond Volume (Cubic Feet) 12 Rating Curve For O~tlet Control Structure Weir Length(L): 2.00 De th Vs. Volume Elevation Depth Di scharge (Feet) Ft3/Sec 285 .00 0 .00 0 .00 285 .22 0 .22 0.62 285.47 0.47 1.93 286 .00 1.00 6.00 286 .50 1.50 11 .02 286 .75 1.75 13 .89 Rating Curve For Outlet Control Structure Depth Vs. Volume i 1.00 ~---+----+----1----+----+----t------I u.. ....., t ~ 0.80 0 .00 0 .00 2.00 4 .00 6 .00 8 .00 10.00 12 .00 14 .00 Discharge (Cubic Feet Per Second) 13 I Storage Indication Curve Depth Storage Discharge 2s/t 2s/t+O (Feet) (Ft3) (Ft3/Sec) (Ft3/Sec) (Ft3/Sec) 0 .00 0 0 .00 0 .00 0 .00 0.22 40 0.62 1.33 1.95 0.47 490 1.93 16.33 18.27 1.00 2,361 6.00 78 .70 84.70 1.50 4,616 11.02 153.87 164.89 1.75 5 ,867 13.89 195.57 209.46 Storage Indication Curve 14.00 12 .00 -10 .00 "O c: 0 0 ~ .... Q) Q. 8.00 -Q) Q) ..... 0 :0 :J (.) 6.00 ........ Q) O> .... 0 ..c: ~ 0 4.00 2 .00 0 .00 0 .00 50.00 100 .00 150 .00 200.00 250 .00 2s/t+O (Cubic Feet Per Second) 14 Inflow I Outflow Simulation 2-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0.00 0.00 0.00 0.00 0.00 285.00 0.00 1 0.88 0.88 0.32 0.88 0.28 0.13 285.13 1.08 2 1.76 2.65 1.57 2.97 0.70 0.24 285.24 1.47 3 2.65 4.41 4.09 5.98 0.94 0.29 285.29 1.62 4 3.53 6.17 7.69 10.27 1.29 0.36 285.36 1.80 5 4.41 7.94 12.19 15.63 1.72 0.43 285.43 1.98 6 5.29 9.70 17.58 21.89 2.16 0.51 285.51 2.13 7 6.17 11.47 23.86 29.05 2.59 0.57 285.57 2.27 8 7.06 13.23 30.92 37.09 3.09 0.64 285.64 2.40 9 7.94 15.00 38.66 45.92 3.63 0.71 285.71 2.54 10 8.82 16.76 47.01 55.43 4.21 0.79 285.79 2.67 11 8.38 17.20 54.72 64.21 4.75 0.86 285.86 2.77 12 7.94 16.32 60.71 71.04 5.16 0.90 285.90 2.85 13 7.50 15.44 65.19 76.15 5.48 0.94 285.94 2.91 14 7.06 14.55 68.36 79.75 5.70 0.97 285.97 2.95 15 6.62 13.67 70.36 82.03 5.84 0.98 285.98 2.97 16 6.17 12.79 71.34 83.15 5.90 0.99 285.99 2.98 17 5.73 11.91 71.42 83.25 5.91 0.99 285.99 2.99 18 5.29 11.03 70.73 82.45 5.86 0.98 285.98 2.98 19 4.85 10.14 69.34 80.87 5.77 0.97 285.97 2.96 20 4.41 9.26 67.35 78.60 5.63 0.96 285.96 2.94 21 3.97 8.38 64.83 ·75.73 5.45 0.94 285.94 2.91 22 3.53 7.50 61.84 72.32 5.24 0.91 285.91 2.87 23 3.09 6.62 58.44 68.46 5.01 0.89 285.89 2.82 24 2.65 5.73 54.69 64.18 4.74 0.86 285.86 2.77 25 2.21 4.85 50.62 59.54 4.46 0.82 285.82 2.72 26 1.76 3.97 46.28 54.59 4.16 0.78 285.78 2.65 27 1.32 3.09 41.69 49.37 3.84 0.74 285.74 2.58 28 0.88 2.21 36.89 43.90 3.50 0.70 285.70 2.51 29 0.44 1.32 31.91 38.22 3.15 0.65 285.65 2.42 30 0.00 0.44 26.76 32.35 2.80 0.60 285.60 2.33 15 Inflow/Outflow Simulation 2-Year Storm Event ...... "O c 0 16.00 14.00 12 .00 ~ 10.00 : i u.. 8.00 0 :0 :::::J ~ ~ 6 .00 :g 0 4 .00 2.00 0.00 0 ----Pre - Devej opme nt 1 Hydrograph I • I I 5 I I I I ' 10 ' ' ' .. ' 15 20 Time (Minutes) Post - De velopme nt Outflow Hydrograph With o ut Detention ----Post- Developme nt Outflow With Detention 16 25 30 -• -• -• Post- Developme nt "Free- Flow' Inflow I Outflow Simulation 5-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0.00 0.00 0.00 0.00 0.00 285.00 0.00 1 1.07 1.07 0.39 1.07 0.34 0.15 285.15 1.15 2 2.15 3.22 2.10 3.61 0.75 0.25 285.25 1.50 3 3.22 5.36 5.34 7.47 1.06 0.32 285.32 1.69 4 4.29 7.51 9.86 12.85 1.50 0.40 285.40 1.89 5 5.36 9.65 15.49 19.51 2.01 0.48 285.48 2.08 6 6.44 11.80 22.32 27.29 2.49 0.56 285.56 2.24 7 7.51 13.94 30.19 36.26 3.03 0.63 285.63 2.39 8 8.58 16.09 38.99 46.28 3.65 0.72 285.72 2.54 9 9.65 18.23 48.58 57.22 4.32 0.80 285.80 2.69 10 10.73 20.38 58.89 68.96 5.04 0.89 285.89 2.83 11 10.19 20.92 68.41 79.81 5.70 0.97 285.97 2.95 12 9.65 19.84 75.80 88.25 6.22 1.02 286.02 3.04 13 9.12 18.77 81.34 94.58 6.62 1.07 286.07 3.10 14 8.58 17.70 85.24 99.04 6.90 1.10 286.10 3.14 15 8.04 16.63 87.72 101.87 7.08 1.12 286.12 3.17 16 7.51 15.55 88.94 103.27 7.16 1.13 286.13 3.18 17 6.97 14.48 89.08 103.42 7.17 1.13 286.13 3.18 18 6.44 13.41 88.26 102.49 7.11 1.12 286.12 3.18 19 5.90 12.34 86.60 100.59 7.00 1.11 286.11 3.16 20 5.36 11.26 84.22 97.86 6.82 1.09 286.09 3.13 21 4.83 10.19 81.19 94.41 6.61 1.07 286.07 3.10 22 4.29 9.12 77.60 90.31 6.35 1.04 286.04 3.06 23 3.75 8.04 73.53 85.65 6.06 1.01 286.01 3.01 24 3.22 6.97 69.02 80.50 5.74 0.97 285.97 2.96 25 2.68 5.90 64.11 74.92 5.40 0.93 285.93 2.90 26 2.15 4.83 58.87 68.94 5.04 0.89 285.89 2.83 27 1.61 3.75 53.33 62.62 4.65 0.84 285.84 2.76 28 1.07 2.68 47.52 56.01 4.24 0.79 285.79 2.67 29 0.54 1.61 41.48 49.13 3.82 0.74 285.74 2.58 30 0.00 0.54 35.25 42.02 3.39 0.68 285.68 2.48 17 18 .00 16.00 14.00 """ "O 5 12.00 0 ~ a; Q.. 10.00 $ LI. 0 :0 :J 8.00 (.) -?; 0 =§ 6.00 0 4.00 2.00 0.00 Inflow/Outflow Simulation 5-Yeor Storm Event 0 5 Pre-- Developme nt Hy drograph -- I I I - ' I ' I ' I ' I I 10 ' ' ' ' ' 15 20 Time (Minutes) Post -Post- De velopme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 18 25 ........ 30 Post- Developme nt 'Free- Flow' Inflow I Outflow Simulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (FVSec) 0 0.00 0 .00 0 .00 0.00 0.00 0 .00 285.00 0.00 1 1.20 1.20 0.44 1.20 0.38 0.16 285.16 1.20 2 2.41 3 .61 2.48 4.05 0.79 0.26 285.26 1.53 3 3 .61 6.02 6.20 8.50 1.15 0.33 285.33 1.73 4 4.82 8.43 11.35 14.63 1.64 0.42 285.42 1.95 5 6.02 10 .84 17.84 22.19 2.17 0 .51 285.51 2.14 6 7 .22 13 .24 25 .65 31 .08 2.72 0 .59 285 .59 2.30 7 8.43 15 .65 34 .61 41.30 3.34 0 .68 285 .68 2.47 8 9.63 18.06 44.59 52.67 4.04 0.77 285.77 2.63 9 10.84 20.47 55 .46 65.06 4 .80 0.86 285 .86 2 .78 10 12.04 22 .87 67.12 78 .34 5.61 0.96 285.96 2.93 11 11.44 23.48 77 .86 90 .59 6.37 1.04 286.04 3.06 12 10.84 22 .27 86 .20 100.13 6.97 1.10 286.10 3.15 13 10.23 21 .07 92.44 107.26 7.41 1.15 286 .15 3 .22 14 9 .63 19.86 96 .84 112.30 7 .73 1.18 286.18 3 .26 15 9 .03 18 .66 99 .65 115.51 7.93 1.20 286.20 3 .29 16 8.43 17.46 101 .04 117.10 8.03 1.21 286 .21 3 .31 17 7 .83 16 .25 101 .21 117.30 8.04 1.22 286 .22 3 .31 18 7 .22 15 .05 100.31 116.26 7.98 1.21 286.21 3 .30 19 6 .62 13 .85 98.46 114.15 7.84 1.20 286 .20 3 .28 20 6.02 12 .64 95 .80 111.11 7.65 1.18 286.18 3 .25 21 5.42 11.44 92.41 107.24 7.41 1.15 286.15 3.22 22 4 .82 10.23 88.40 102.65 7 .12 1.12 286 .12 3 .18 23 4 .21 9.03 83 .83 97.43 6.80 1.09 286 .09 3.13 24 3 .61 7.83 78 .79 91 .66 6.44 1.05 286 .05 3.07 25 3 .01 6.62 73 .32 85.41 6.04 1.00 286 .00 3.01 26 2 .41 5.42 67.47 78.74 5.63 0.96 285 .96 2.94 27 1.81 4 .21 61 .27 71.68 5.20 0 .91 285 .91 2 .86 28 1.20 3 .01 54 .78 64 .28 4.75 0.86 285 .86 2.78 29 0 .60 1.81 48 .03 56.59 4 .28 0.80 285 .80 2.68 30 0 .00 0 .60 41.05 48.63 3 .79 0 .74 285 .74 2.57 19 20.00 18.00 16.00 -14.00 "O c 0 ~ a; 12.00 Q. a; Cl> u... 10.00 0 :0 ::::J g ~ !§ 0 8.00 6 .00 4 .00 2 .00 0.00 Inflow/Outflow Simulation 10-Year Storm Event 0 5 Pre-- Developme nt Hydrograph -- I I I I I - • I I ' ' I 10 ' ' ' .. ' • ' 15 20 Time (Minutes) Post-Post- Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 20 25 .... -. -. 30 Post- Developme nt 'Free- Flow' Inflow I Outflow Simulation 25-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0 .00 0 .00 0.00 0.00 0.00 285.00 0.00 1 1.38 1.38 0.50 1.38 0.44 0 .17 285.17 1.25 2 2 .75 4.13 2.96 4 .63 0.83 0 .27 285.27 1.55 3 4 .13 6 .88 7.33 9.83 1.25 0.35 285 .35 1.78 4 5 .50 9 .63 13.30 16.95 1.83 0.45 285.45 2 .02 5 6.88 12 .38 20 .90 25 .67 2 .39 0 .54 285.54 2.21 6 8.25 15.13 29 .98 36 .02 3.02 0.63 285 .63 2.39 7 9.63 17 .88 40 .37 47.86 3 .74 0.73 285 .73 2 .56 8 11 .00 20 .63 51 .90 60.99 4.55 0 .83 285.83 2.74 9 12 .38 23 .38 64.43 75.27 5.42 0 .93 285.93 2.90 10 13.75 26 .13 77.82 90.55 6.37 1.04 286.04 3.06 11 13.06 26 .81 90 .13 104.63 7 .25 1.13 286 .13 3.20 12 12 .38 25.44 99 .70 115.57 7 .93 1.20 286.20 3.29 13 11.69 24 .06 106.87 123.77 8.45 1.26 286.26 3 .36 14 11 .00 22 .69 111 .94 129.56 8.81 1.29 286 .29 3.41 15 10.31 21 .31 115.17 133.25 9.04 1.31 286 .31 3.44 16 9 .63 19 .94 116.79 135.11 9 .16 1.33 286 .33 3.45 17 8 .94 18.56 117.01 135.36 9.17 1.33 286.33 3.46 18 8.25 17 .19 116.00 134.20 9.10 1.32 286 .32 3.45 19 7 .56 15 .81 113.91 131 .81 8.95 1.31 286.31 3.43 20 6.88 14.44 110.88 128.35 8.73 1.28 286 .28 3.40 21 6.19 13 .06 107.03 123.94 8.46 1.26 286 .26 3.36 22 5 .50 11 .69 102.45 118.71 8.13 1.22 286 .22 3.32 23 4.81 10.31 97 .25 112.76 7.76 1.19 286 .19 3.27 24 4 .13 8.94 91 .50 106.19 7.35 1.14 286 .14 3.21 25 3.44 7 .56 85.26 99.06 6.90 1.10 286 .10 3 .14 26 2.75 6.19 78 .60 91.45 6.42 1.05 286 .05 3.07 27 2.06 4 .81 71 .57 83.41 5 .92 0 .99 285 .99 2.99 28 1.38 3.44 64 .20 75 .01 5.41 0 .93 285 .93 2 .90 29 0 .69 2.06 56 .52 66.26 4.87 0.87 285 .87 2 .80 30 0 .00 0 .69 48 .57 57.20 4 .32 0 .80 285 .80 2.69 21 B c: 0 25 .00 20.00 -~ .,, 15.00 5.00 0.00 Inflow/Outflow Simulation 25-Year Storm Event I I 0 5 Pre-. . . . Developme nt Hydrograph I I I I ' I ' 10 ' ' ' ' ' ' 15 20 Time (Minutes) Post-Post- Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 22 25 . ....... 30 Post- Develo pme nt "Free- Flow· Inflow I Outflow Simulation 50-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (FVSec) 0 0.00 0.00 0.00 0 .00 0.00 0 .00 285.00 0.00 1 1.55 1.55 0 .57 1.55 0 .49 0 .19 285 .19 1.30 2 3 .11 4.66 3.47 5 .23 0.88 0.28 285 .28 1.58 3 4.66 7 .77 8.50 11 .24 1.37 0 .37 285.37 1.83 4 6.22 10.88 15.38 19 .38 2.00 0.48 285.48 2.08 5 7 .77 13 .99 24 .14 29 .37 2.61 0 .57 285 .57 2.27 6 9.33 17 .10 34 .56 41.24 3 .34 0 .68 285.68 2.47 7 10 .88 20 .21 46.43 54.77 4 .17 0 .78 285.78 2.66 8 12.43 23 .32 59 .58 69 .75 5 .08 0.90 285.90 2.84 9 13 .99 26.42 73 .84 86 .00 6.08 1.01 286.01 3 .01 10 15.54 29 .53 89 .03 103.37 7.17 1.13 286 .13 3.18 11 14.77 30.31 103.00 119 .34 8.17 1.23 286 .23 3.33 12 13 .99 28 .76 113.86 131 .76 8 .95 1.31 286.31 3.43 13 13 .21 27 .20 122 .00 141 .06 9.53 1.36 286 .36 3.50 14 12.43 25.65 127.76 147.65 9.94 1.40 286 .40 3 .55 15 11 .66 24 .09 131.44 151.86 10.21 1.42 286.42 3.58 16 10.88 22.54 133.30 153.98 10 .34 1.44 286.44 3.60 17 10 .10 20 .98 133.57 154.29 10 .36 1.44 286.44 3 .60 18 9 .33 19.43 132.44 153.00 10.28 1.43 286.43 3.59 19 8.55 17 .87 130.10 150.32 10.11 1.42 286.42 3.57 20 7 .77 16 .32 126.69 146.42 9.87 1.39 286.39 3.54 21 6.99 14 .77 122.34 141.45 9.55 1.36 286.36 3 .50 22 6.22 13.21 117.18 135.56 9.19 1.33 286 .33 3.46 23 5.44 11.66 111 .31 128.84 8.76 1.29 286 .29 3.40 24 4.66 10.10 104.82 121.42 8.30 1.24 286 .24 3.34 25 3.89 8.55 97 .77 113.37 7 .80 1.19 286 .19 3 .27 26 3 .11 6.99 90.25 104.77 7 .26 1.14 286.14 3.20 27 2.33 5.44 82 .32 95 .69 6.69 1.08 286 .08 3 .11 28 1.55 3 .89 74.02 86 .20 6.09 1.01 286.01 3 .02 29 0 .78 2.33 65 .37 76 .35 5.49 0.94 285.94 2.91 30 0.00 0 .78 56.42 66.15 4 .86 0.87 285 .87 2.80 23 Inflow/Outflow Simulation 50-Year Storm Event 25 .00 I " I " I " • • I " I ' I " 20 .00 • ' I I " I ...... "O c 0 0 ~ ... 15 .00 Q) " 0.. -' Q) " Q) u.. 0 ' :0 ' :I " (.) ....,, 10.00 ~ 0 = :I 0 5.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre-----Post-Post-... -.. -. Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrograph Hydrograph With Flow' Without Detention Det ention 24 Inflow I Outflow Simulation 100· Year Storm Event Time Inflow 11+ 12 2s/t -0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0 .00 0 .00 0.00 0.00 0.00 0 .00 285.00 0.00 1 1.62 1.62 0.59 1.62 0.51 0 .19 285.19 1.32 2 3.25 4 .87 3.66 5.46 0.90 0.28 285.28 1.60 3 4.87 8.11 8.95 11.77 1.41 0 .38 285 .38 1.85 4 6.49 11 .36 16.20 20 .31 2.06 0.49 285.49 2 .10 5 8.11 14 .61 25.40 30.80 2.70 0 .59 285.59 2 .30 6 9 .74 17 .85 36 .33 43 .25 3.46 0.69 285 .69 2.50 7 11 .36 21 .10 48 .76 57.42 4 .33 0.80 285.80 2.69 8 12 .98 24 .34 62 .53 73 .11 5.29 0 .92 285.92 2 .88 9 14 .61 27.59 77 .44 90 .11 6.34 1.04 286.04 3.06 10 16.23 30.83 93.32 108.27 7.48 1.16 286 .16 3 .23 11 15.42 31.65 107.92 124.96 8 .52 1.26 286 .26 3 .37 12 14 .61 30 .02 119 .27 137.94 9 .33 1.34 286 .34 3.48 13 13 .79 28.40 127.79 147.67 9 .94 1.40 286.40 3.55 14 12.98 26 .78 133.81 154.56 10.38 1.44 286.44 3.60 15 12 .17 25 .15 137.66 158.97 10 .65 1.47 286.47 3.63 16 11.36 23 .53 139 .61 161.19 10 .79 1.48 286.48 3 .65 17 10 .55 21 .91 139 .90 161.52 10 .81 1.48 286 .48 3.65 18 9.74 20 .29 138.73 160.18 10 .73 1.47 286.47 3 .64 19 8 .93 18 .66 136.28 157.39 10.55 1.46 286.46 3.62 20 8.11 17 .04 132 .73 153.32 10.30 1.43 286.43 3.59 21 7 .30 15.42 128.20 148.15 9.97 1.40 286.40 3 .55 22 6.49 13 .79 122 .81 141 .99 9.59 1.37 286.37 3.51 23 5 .68 12 .17 116.69 134.99 9.15 1.32 286 .32 3.45 24 4 .87 10 .55 109.91 127.24 8.66 1.28 286.28 3.39 25 4 .06 8 .93 102 .56 118.83 8.14 1.23 286.23 3 .32 26 3.25 7.30 94 .71 109.86 7 .58 1.17 286.17 3 .24 27 2.43 5.68 86.42 100.39 6.98 1.11 286 .11 3 .16 28 1.62 4.06 77 .76 90.48 6.36 1.04 286 .04 3.06 29 0 .81 2.43 68 .74 80.19 5 .72 0.97 285.97 2.95 30 0 .00 0 .81 59.41 69 .55 5.07 0.89 285 .89 2 .84 25 30 .00 25 .00 ....... "O 5 20 .00 ~ Cl) a; '1.. l u.. 15.00 0 :0 j ~ ~ ~ 10 .00 0 5 .00 0 .00 Inflow/Outflow Simulation 100-Year Storm Event 0 5 Pre-- Developme nt Hydrograph -- I I I I - ' ' I ' • ' I ' ' ' ' 10 15 20 25 30 Time (Minutes) Post-Post-........ -Post- Develo pme De velopme Developm e nt Outflow nt O utflow nt "Free- Hydrograph With Flow" Without Detention Detention 26 Inflow/Outflow Simulation 2-Year Storm Event 12 .00 10 .00 -8.00 "O c 0 ~ ... G> Q.. l 6 .00 u.. () :0 j 0 ...... ~ 0 !§ 0 4 .00 2 .00 0 .00 0 5 10 15 20 25 30 Time (Minutes) Pre -Development Hydrograph ----Total Post-Development Hydrogra p h 27 Inflow/Outflow Simulation 5-Year Storm Event 14.00 12 .00 10 .00 ....... 'O c 0 0 Q) Cl) ... 8 .00 Q) A. -Q) Q) ~ 0 :0 j () 6.00 ....., ~ 0 =§ 0 4 .00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) ---Pre-De velopment Hydrograph ----Total Po st-Development Hydrograph 28 Inflow/Outflow Simulation 10-Year Storm Event 10 .00 ....... "O c 0 ~ Cl) ... 8 .00 G> a.. l u.. 0 :a ::::J 0 6 .00 ....... ~ 0 =§ 0 4.00 0 5 10 15 20 25 30 Time (Minutes) Pre -Dev elopment Hydrograph ----Total Post-Development Hydrograph 29 Inflow/Outflow Simulation 25-Year Storm Event 12.00 ...... "O c: 0 10.00 ~ (I) ... G> Q.. l 8.00 ..... 0 :0 :::J (.) ...., ~ 0 6.00 :g 0 4 .00 0 5 10 15 20 25 30 Time (Minutes) ---Pre -De velopment Hydrograph ---Total Post-Development Hydrograph 30 Inflow/Outflow Simulation 50-Year Storm Event 18 .00 16.00 14.00 -12.00 "O c 0 0 G> Cl) ... G> 10 .00 Q.. -G> G> ..... 0 :0 8 .00 :J () ...... ~ 0 =§ 0 6 .00 4.00 2 .00 0 .00 0 5 10 15 20 25 30 Time (Minutes) Pre-Development Hydrograph ----Total Post-Development Hydrograph 31 Inflow/Outflow Simulation 100-Year Storm Event 20 .00 18 .00 16 .00 14 .00 ....... "O c 0 0 G> 12.00 (f) ... G> 0.. -G> G> 10.00 LL. 0 :a ::J u -~ 8 .00 0 = ::J 0 6 .00 4 .00 2.00 0 .00 0 5 10 15 20 25 30 Time (Minutes) Pre -Development Hydrograph ----Tot a l Post-Development Hydrograph 32 Detention Pond Storage Volumes as Percent of Maximum Volume 100% 90% 80% 70% ~ :J 0 60% > E :J E ')( 50% 0 ~ 0 -40% c: G> 2 G> 0.. 30% 20% 10% 0% 2-year 5-year 10-y ear 25-year 50-year 100 -year Design Storm Storm Depth Storm Elevation 285.99 286 .13 286 .22 286.33 286.48 Storm Volume 2326 2807 3333 3836 4341 4529 Maximum Capacity 5867 5867 5867 5867 5867 5867 Percent of Capacity 40% 48% 57 % 65% 74% 77% 33 DEVELOPMENT PERMIT PERMIT NO. 350 SOUTHWOOD VALLEY SECTION 24A, TRACT B, BLOCK 55 FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: Southwood Valley Section 24A, Tract B , Block 55 SITE ADDRESS: Clovis Court OWNER: Thomas Properties P .O . Box 10106 College Station, TX 77840 (409) 764-0704 DRAINAGE BASIN: Bee Creek Tributary A Channel II TYPE OF DEVELOPMENT: This permit is valid for the construction of street, water, drainage, and sanitary sewer improvements according to approved plans . Contractor shall prevent silt and debris from leaving the site in accordance with the City of College Station Drainage Policy and Design Criteria. Owner and/or contractor shall be responsible for any damage to existing city streets or infrastructure due to heavy machinery and/or equipment. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities . I hereby grant this permit for development of an area outside the special flood hazard area. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit application for the above named project and all of the codes and ordinances of the City of College Station that apply. s~~ Date !L.i Date 12, 199~ ' DRAINAGE COMPUTATIONS For A Replat Of Tract 11 8 11 , Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas Prepared By: Garrett Engineering 4444 Carter Creek Parkway -Suite 108 Bryan , Texas 77802 Telephone: ( 409) 846-2688 DRAINAGE COMPUTATIONS For A Rep lat of Tract "B ", Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas * September, 1994 * SUMMARY The project is situated adjacent to Welsh Ave., and south of San Mario Ct. in Southwood Valley, College Station, Brazos County, Texas. Tract "B", Block 55 of Southwood Valley -Section 24A consists of 15 lots, these 15 lots being established within the bounds of a 3.93 acre tract. The total drainage arj a tributary to the projec is 3.93 acres. The pre-development run-off coefficient was estimated to be 0.40J while taking into acco nt typical residential site improvements would result in a post-development run-off coefficient of 0.56. A detention facility will be constructed in the northwest comer of the property as designated on the plat. The detention pond is designed to facit i te up to and including the 100-year storm event, and discharge at a rate less than the current pre-develop ent peak discharge rat The detention pond will intercept, store and meter run-off from 2.50 acres of e project. The run-off enerated on the remaining 1.43 acres will "free-flow" across the project site unmetered off the property. From the computations on page 1, based on the total tributary drainage area of the project being estimated at 3.93 acres, the pre-development run-off coefficient being assumed at 0.40, and a minimum time of concentration of 10 minutes, the relative pre-development peak discharge rate ("Q") was determined. The Rational Method was utilized to comp~ue the estimated peak pre-development discharge rates. The equation that represents the Rational Meth d is as follows: Q = CIA. "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off co fficient, assumed to be 0.40 in the pre-development condition, "I" is the storm intensity in inches per ho , and "A" is the area of the drainage basin in acres. From the computations on page 2, based on the tributary area of 3.93 acres, the post-development run-off coefficient being assumed at 0.56, and a minimum time of concentration of 10 minutes, the relative pre- development peak discharge rate ("Q") was determined assuming the same minimum time of concentration of 10 minutes. The Rational Method was again utilized to compute the estimated peak post- development discharge rates . The equation that re presents the Rational Method is as follows: Q = CIA, where; "Q" is the peak discharge rate in cubic feet per second. "C" is the run-off coefficient, in the post- development condition "C" is assumed to be 0.56 , "I" is the storm intensity in inches per hour and "A" is the area of the basin in acres . The comparison between the peak pre-development discharge rate and post-development discharge rate is included as an aid to the designer to establish a preliminary "target" for the necessary volume in the proposed detention facility. This preliminary estimate is found by simply determining the volume generated from the difference between the pre-development and post-development hydrographs (see pages 9-11 for pre-development and post-development hydrographs). Please note that the post-development hydrograph shown on these same graphs assumes no detention. Page 3 and page 4 provide computations that determine the post-development run-off that is not routed through the detention facility ("free-flow") and post-development run-off that is routed through the detention facility. Page 5 and page 6 are tabulations of the pre-development hydrograph and the post-development hydrograph based on the computations performed on page 1 and page 2. The post-development hydrograph assumes no detention to facilitate direct comparison in the pre-and post-development conditions. Page 7 and page 8 are tabulations of the post-development hydrograph for run-off directed through the detention facility and the post-development hydrograph for "free-flow" from the project site. Computations on page 4 determine the actual peak post-development "inflow" rate supplied to the proposed detention facility. From this "inflow" rate and the time of concentration (10 minutes minimum), a hydrograph as tabulated on page 8 can be derived. The hydrograph is triangular in shape and is based on the standard SCS unit hydrograph with time to peak set equal to the time of concentration and the total time base set at 3.00 times the time of concentration. Please note that a 30 minute total storm event duration was utilized exclusively throughout this report due totally to the small physical size of the project Having derived the preliminary volume requirements and "allowable peak" discharge rate, it is now possible to design the final detention facility and outlet control structure. Page 12 presents a tabulation and a depth versus volume graph of the detention facility. The maximum depth of the pond was set at 1.98' (top retaining wall less flow line "out" of outlet control structure: 286.75' -284.77' = 1.98'). Page 13 supplies a tabulation and a rating curve for the proposed outlet control structure. A rectangular weir was decided upon due to depth verses discharge ratio characteristics associated with the anticipated shallow headwater depth (maximum of 1.98') and the fixed weir width of 1.21' (1'-2-1/2"). The equation used to determine discharge was Q = CLH3/2 where "Q" is the discharge rate in cubic feet per second. "C" is the coefficient of discharge, in this case assumed to be set at 3.000. "L" is the width of the weir in feet, in this case assumed to be set at 1.21 '. "H" is the headwater depth in feet (ranges from O' to a maximum of 1.98'). Page 14 presents a tabulation of the relationship between discharge from the detention facility and the dimensionless quantity 2S/t-O. Also presented is a Storage Indication Curve for the detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrograph, and rating curve for the outlet structure. The storage indication curve as shown on page 12 is a graphical solution to the equation presented in the "Drainai:e Policy And Desii:n Standards" as follows: 2s 1 01 +Ii)+(----------------01) = dt 2s2 (-----------------+ Oi) dt Page 15 through page 26 present simulations of the 2, 5, 10, 25, 50, and 100 year storm events. The first page of each storm simulation represents the tabulated data for the storm event. The maximum depth achieved in the detention pond during each simulation is shown below as is the time period during which this maximum depth occurs after the beginning of the storm event. The calculated peak discharge rate corresponding to this depth over same period is also shown below. Additionally, the maximum water surface elevation achieved during each event and the maximum peak discharge during each event are listed below. The second page of each storm simulation represents the pre-development hydrograph, the post-development hydrograph (with no detention), the post-development hydrograph as routed through the detention pond, and post-development "free-flow" hydrograph for each storm event Storm Max Depth (Year) (Ft) 2-year 1.37 5-year 1.53 10-year 1.63 25-year 1.78 50-year 1.92 100-yearl.98 Time Period (Min) 17 17 17-19 17-18 17-19 18 Max Discharge Max Elev (CFS) (Ft MSL) 5.80 286.14 6.84 286.30 7.58 286.40 8.61 286.55 9.69 286.69 10.10 286 .75 Max Velocity (Ft/Sec) 3.51 3.71 3.84 4.00 4.16 4.22 Page 27 through page 32 provide total inflow/outflow hydrographs for the 2, 5, 10, 25, 50 and 100-year pre-development and post-development storm events. It can be determined from these same hydrographs that the post-development peak discharge rates have been minutely decreased from those peak pre- development discharge rates due to the incorporation of the detention facility in the post-development condition. Total post-development peak discharge rates from the detention pond outlet control structure and project site are kept less than the pre-development peak discharge rates due to the incorporation of the proposed detention facilities. Subsequent peak post-development discharge velocities projected to be within manageable limits. Determine Total Pre-Development Peak Storm Water Discharge Rates Tributary Area ("A"): 3 .93 Acres Pervious Area: 3.93 Acres Impervious Area: 0.00 Acres Run-Off Coefficient ("Cwt"): 0.40 - Time Of Concentration ("T/c"): Woodlands: Low Elevation : High Elevation : Distance (Feet): Slope (% Grade): Velocity ("Vw"): Time: Pastures: Low Elevation : High Elevation : Distance (Feet): Slope (%Grade): Velocity ("Vp"): Time : Pavements: Low Elevation: High Elevation: Distance (Feet): Slope (%Grade): Velocity ("Vpave"): Time : Total Travel Time: Hourly Intensity Rates ("I"): 2-Year: 6.33 ' 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11 .64 I Peak Discharge Rate ("Q"): 2-Year: 9.95_ 5-Year: 12 .09 10-Year: 13.57 25-Year: 15.50 50-Year: 17.52 100-Year: 18.30· c = 0.40 C= 0 .98 0.00 0.00 0 .00 0.00 0.00 Feet I Second 0.00 Minutes 0 .00 0.00 0.00 0.00 0 .00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0 .00 0.00 Feet I Second 0.00 Minutes 10.00 Minutes Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determine Post-development Peak Storm Water Dischar e No Detention Tributary Area ("A"): 3.93 Acres Pervious Area : 2.84 Acres Impervious Area : 1.09 Acres Run-Off Coefficient ("Cwt"): 0 .56 J Time Of Concentration ("T/c"): 1 O Minutes (Min) ./ Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 13.94 5-Year: 16.96 10-Year: 19.03 25-Year: 21 .74 50-Year: 24.57 100-Year: 25.66 Comparison Of Predevel opment An d Post-develo ment Peak Dischar e Rates C= 0.40 I C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Predevelopment Post-Development Increase 2-Year: 9 .95 Ft3/sec 13 .94 Ft3/sec 5-Year: 12 .09 Ft3/sec 16.96 Ft3/sec 10-Year: 13.57 Ft3/sec 19 .03 Ft3/sec 25-Year: 15.50 Ft3/sec 21.74 Ft3/sec 50-Year: 17 .52 Ft3/sec 24.57 Ft3/sec 100-Year: 18.30 Ft3/sec 25.66 Ft3/sec Preliminary Determination Of Detention Pond Volume 2-Year: 4.00 Ft3/sec x (30 Min. x 60 Sec . I 2 ) = 5-Year: 4.86 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 10-Year: 5.46 Ft3/sec x (30 Min . x 60 Sec. I 2 ) = 25-Year: 6.23 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 50-Year: 7.05 Ft3/sec x (30 Min. x 60 Sec . I 2 ) = 100-Year: 7.36 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 4 .00 Ft3/sec 4.86 Ft3/sec 5.46 Ft3/sec 6.23 Ft3/sec 7 .05 Ft3/sec 7 .36 Ft3/sec 3,600 Cubic Feet 4,377 Cubic Feet 4,913 Cubic Feet 5,611 Cubic Feet 6,343 Cubic Feet 6,622 Cubic Feet Determine Post-Development "Free-Flow" Peak Storm Water Dischar e Tributary Area ("A"): 1.43 Acres Pervious Area: 1.00 Acres Impervious Area : 0.43 Acres Run-Off Coefficient ("Cwt"): 0.57 Time Of Concentration ("T/c"): 1 O Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7 .69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 5 .20 5-Year: 6.32 10-Year: 7.09 25-Year: 8.10 50-Year: 9.16 100-Year: 9.56 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determln'-Post-Development Flow Into Detention Pond Tributary Area ("A"): 2.50 Acres Pervious Area: 1.78 Acres Impervious Area: 0 .72 Acres Run-Off Coefficient ("Cwt"): 0.57 Time Of Concentration ("T/c"): 1 O Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7 .69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 8.97 5-Year: 10.91 10-Year: 12.24 25-Year: 13.98 50-Year: 15.80 100-Year: 16.50 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cub ic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Pre-Development Storm Intensity Rates (Inches Per Hour) 5-Year 10-Year 25-Year 50-Yaar 100-Year Storm Storm Storm Storm Storm Storm 0.00 0 .00 0.00 0 .00 0.00 0 .00 0.99 1.21 1.36 1.55 1.75 1.83 1.99 2 .42 2 .71 3 .10 3 .50 3.66 2 .98 3.63 4 .07 4 .65 5 .26 5.49 3.98 4 .84 5.43 6.20 7 .01 7 .32 4 .97 6 .05 6 .79 7 .75 8.76 9 .15 6 5 .97 7 .26 8.14 9 .30 10.51 10 .98 7 6 .96 8.47 9.50 10.85 12.27 12.81 8 7 .96 9.67 10.86 12.40 14.02 14 .64 9 8.95 10.88 12 .22 13.95 15.77 10 9.95 12.09 13.57 15.50 17.52 11 9.45 11.49 12.89 14.73 16.65 12 8 .95 10.88 12.22 13.95 15.77 16.47 13 8.45 10.28 11 .54 13.18 14.90 15 .55 14 7.96 9 .67 10.86 12.40 14.02 14.64 15 7.46 9 .07 10.18 11 .63 13.14 13.72 16 6 .96 8.47 9.50 10.85 12.27 12 .81 17 6.46 7 .86 8 .82 10.08 11 .39 11.89 5 .97 7 .26 8.14 9.30 10.51 10.98 5.47 6.65 7.47 8.53 9.64 10.06 4 .97 6.05 6 .79 7.75 8 .76 9.15 4 .48 5.44 6 .11 6 .98 7 .89 8.23 3 .98 4.84 5.43 6.20 7 .01 7 .32 3.48 4.23 4.75 5.43 6.13 6.40 2.98 3 .63 4 .07 4.65 5.26 5.49 2 .49 3 .02 3 .39 3.88 4.38 4.57 1.99 2.42 2 .71 3 .10 3.50 3.66 1.49 1.81 2 .04 2.33 2.63 2.74 0.99 1.21 1 .36 1.55 1.75 ' 1.83 0.50 0.60 0 .68 0.78 oia 0.91 30 0 .00 0 .00 0 .00 0.00 /0 / y;.-/' Post-Development I # Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 1.39 1.70 1.90 2.17 2.46 2.57 2 2.79 3.39 3 .81 4.35 4.91 5.13 3 4.18 5.09 5.71 6.52 7.37 7.70 4 5.58 6.78 7 .61 8.69 9.83 10.26 5 6 .97 8.48 9.52 10.87 12 .29 12.83 6 8 .37 10.17 11.42 13.04 14.74 15.39 7 9.76 11.87 13.32 15.22 17.20 17.96 8 11.16 13.57 15.23 17.39 19.66 20.52 9 12.55 15.26 17.13 19.56 22.11 23.09 Peak=> 10 13.94 16.96 19.03 21.74 24.57 25.66 11 13.25 16.11 18.08 20.65 23.34 24.37 12 12.55 15.26 17.13 19.56 22.11 23 .09 13 11 .85 14.41 16.18 18.48 20.89 21.81 14 11.16 13.57 15.23 17.39 19.66 20.52 15 10.46 12.72 14.27 16.30 18.43 19.24 16 9.76 11 .87 13.32 15.22 17.20 17.96 17 9 .06 11.02 12 .37 14.13 15.97 16.68 18 8.37 10.17 11.42 13.04 14.74 15.39 19 7 .67 9.33 10.47 11.96 13.51 14.11 20 6 .97 8.48 9.52 10.87 12.29 12.83 21 6 .28 7.63 8.56 9.78 11.06 11.54 22 5.58 6.78 7.61 8.69 9.83 10.26 23 4.88 5.93 6 .66 7 .61 8.60 8.98 24 4.18 5.09 5.71 6.52 7 .37 7.70 25 3.49 4.24 4.76 5.43 6.14 6.41 26 2 .79 3.39 3 .81 4.35 4.91 5.13 27 2.09 2.54 2.85 3.26 3.69 3.85 28 1.39 1.70 1.90 2.17 2.46 2.57 29 0.70 0.85 0.95 1.09 1.23 1.28 30 0.00 0.00 0.00 0 .00 0.00 0 .00 Detention P~ ~ Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.90 1.09 1.22 1.40 1.58 1.65 2 1.79 2.18 2.45 2.80 3.16 3.30 3 2.69 3.27 3.67 4.19 4.74 4.95 4 3.59 4.36 4.90 5.59 6.32 6.60 5 4.48 5.45 6.12 6.99 7.90 8.25 6 5.38 6.54 7.34 8.39 9.48 9.90 7 6.28 7.63 8.57 9.79 11.06 11.55 8 7.17 8.72 9.79 11.18 12.64 13.20 9 8.07 9.81 11.02 12.58 14.22 14.85 Peak=> r-10 8.97 10.91 12.24 13.98 < 15.80 16.50 11 8.52 10.36 11.63 13.28 15.01 15.67 12 8.07 9.81 11.02 12.58 14.22 14.85 13 7.62 9.27 10.40 11.88 13.43 14.02 14 7.17 8.72 9.79 11.18 12.64 13.20 15 6.73 8.18 9.18 10.48 11.85 12.37 16 6.28 7.63 8.57 9.79 11.06 11.55 17 5.83 7.09 7.96 9.09 10.27 10.72 18 5.38 6.54 7.34 8.39 9.48 9.90 19 4.93 6.00 6.73 7.69 8.69 9.07 20 4.48 5.45 6.12 6.99 7.90 8.25 21 4.04 4.91 5.51 6.29 7.11 7.42 22 3.59 4.36 4.90 5.59 6.32 6.60 23 3.14 3.82 "4.28 4.89 5.53 5.77 24 2.69 3.27 3.67 4.19 4.74 4.95 25 2.24 2.73 3.06 3.49 3.95 4.12 26 1.79 2.18 2.45 2.80 3.16 3.30 27 1.35 1.64 1.84 2.10 2.37 2.47 28 0.90 1.09 1.22 1.40 1.58 1.65 29 0.45 0.55 0.61 0.70 0.79 0.82 30 0.00 0.00 0.00 0.00 0.00 0.00 Post-Development "Free-Flow" Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.52 0.63 0.71 0.81 0.92 0.96 2 1.04 1.26 1.42 1.62 1.83 1.91 3 1.56 1.90 2.13 2.43 2.75 2.87 4 2.08 2.53 2.84 3.24 3.66 3.82 5 2.60 3.16 3.55 4.05 4.58 4.78 6 3.12 3.79 4.26 4.86 5.49 5.74 7 3.64 4.42 4.96 5.67 6.41 6.69 8 4.16 5.06 5.67 6.48 7.33 7.65 9 4.68 5.69 6.38 7.29 8.24 8.60 Peak=> r -10 I. 5.20 6.32. 7.09 (._ "' ' l· 8.10 9.16 9.56 11 4.94 6.00 6.74 7.70 8.70 9.08 12 4.68 5.69 6.38 7.29 8.24 8.60 13 4.42 5.37 6.03 6.89 7.78 8.13 14 4.16 5.06 5.67 6.48 7.33 7.65 15 3.90 4.74 5.32 6.08 6.87 7.17 16 3.64 4.42 4.96 5.67 6.41 6.69 17 3.38 4.11 4.61 5.27 5.95 6.21 18 3.12 3.79 4.26 4.86 5.49 5.74 19 2.86 3.48 3.90 4.46 5.04 5.26 20 2.60 3.16 3.55 4.05 4.58 4.78 21 2.34 2.84 3.19 3.65 4.12 4.30 22 2.08 2.53 2.84 3.24 3.66 3.82 -23 1.82 2.21 2.48 2.84 3.20 3.35 24 1.56 1.90 2.13 2.43 2.75 2.87 25 1.30 1.58 1.77 2.03 2.29 2.39 26 1.04 1.26 1.42 1.62 1.83 1.91 27 0.78 0.95 1.06 1.22 1.37 1.43 28 0.52 0.63 0.71 0.81 0.92 0.96 29 0.26 0.32 0.35 0.41 0.46 0.48 30 0.00 0.00 0.00 0.00 0.00 0.00 ... G> 0... -; G> ...... o-·-"O ..0 c :J 0 (.) 0 -G> &Cl) ... 0 .&; ~ 0 14.00 ... G> 12.00 0... l 10.00 ...... o-·-"O 8.00 .0 c :J 0 (.) 0 6.00 -~ & ... 4 .00 0 .&; ~ 2.00 0 0.00 0 ~v~~~;~ / Total Pre-Development Hydrograph Vs. Total Post-J1'L Development Hydrograph For 2-Year Storm Eve ,T-__ %~\-"''{)1 7,0 ,z,\~·\l 5 10 15 20 25 3C Time (Minutes) ---Pre-Development Hydrograph ---Tota l Post-Development Hydrograph 18 .00 16 .00 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 0 ./ ~ .. v 8~ // ~~ c._::__ j(' ~\ / Total Pre-Development Vs. Total Post-Development (No ~ Detention) Peak Discharge Rates 5-Year Storm Event 0\,\ )( \i,"11 'l 11;) \'\)· \ ·"' 5 10 15 20 25 30 Time (Minutes) ---Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detention ... G> CL 'i Cl) LL. o -·-"O ..0 c ::::J 0 ~~ & ... 0 .J: ~ a ... Cl) CL Q; Cl) LL. o-·-"O ..0 c ::::J 0 ~~ & ... 0 .J: .~ 0 20.00 18 .00 16 .00 14.00 12.00 10 .00 8.00 6.00 4.00 2.00 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention ) Peak Discharge Rates 10-Year Storm Even t tW I\ .~Ii\ ~ Q ? "O ~' \ \' 5 10 15 20 25 Time (Minutes ) 30 Pre -Development Hydrograph ---Post-Development Outflow Hyd rograph Without Detention 25.00 20.00 15.00 10.00 5.00 0.00 0 Total Pre -Development Vs. Total Post-Development (No Detention ) Peak Discharge Rates 25-Year Storm Even t 5 10 15 20 25 Ti me (M inutes ) 30 ---Pre -Development Hydrograph ---Post-Developm e nt Outflow Hydrograph Wi t hout Detention 25 .00 ... Q) Q.. Gi 20 .00 Q) u.. o-15 .00 ·-1J .0 c :::J 0 ~~ 10 .00 & ... 0 .s:::. 5.00 .~ 0 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 50-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pre-Development Hydr o gra p h ---Po st-Development Outflow Hydro g raph Witho ut Det enti on 30 .00 ... Q) Q.. 25 .00 Gi Q) ~ -20 .00 ·-1J .0 c 8 8 15 .00 -Cl> Cl> Cl) 10 .00 O> ... 0 .s:::. 5.00 ~ 0 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 100-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pr e-Dev elopment Hydro graph ---Post-De vel opment Outfl ow Hydrograph Witho ut Det ent ion Detentiog Pond De th Vs. Volume Elevation Depth Volume (Feet) (Ft3) 284.77 0.00 0 285 .00 0.23 69 285.50 0 .73 1,085 286.00 1.23 2,100 286.38 1.61 3,703 286.75 1.98 5,306 Detention Pond Depth Vs. Volume 2.00 1.80 1.60 1.40 c 1.20 Cl> Cl> LI. ....,, 1.00 t Cl> a 0.80 0.60 0 .40 0.20 ~ ~ / v ~ v / / / / ~ / / 0.00 0 1,000 2,000 3,000 4 ,000 5,000 6,000 Detention Pond Volume (Cubic Feet) Rat ing Curve For Outlet Control Structure W e ir Length(L): 1.21 (1 '-2-1/2") De th Vs. Vo l ume Elevatio n Dept h Disc harg e (Fe et) Ft3/Sec 284.77 0.00 0 .00 285 .00 0 .23 0 .4 0 285.50 0 .73 2.2 6 286 .00 1.23 4.95 286.38 1.61 7.42 286 .75 1.98 10 .1 1 Rating Curve For Outlet Control Structure Depth Vs . Volume 2.00 1.80 1.60 1.4 0 -1.20 -$ u. -1.00 .c -a. G> 0 0.80 /- ~ / / / ~ / / v 0 .60 0 .4 0 0.20 0.00 ~ / / I 0 .00 2 .00 4.00 6.00 8.00 10.00 12.00 Discharge (Cubic Feet Per Second) I Storage Indication Curve Depth Storage Discharge 2s/t 2s/t+O (Feet) (Ft3) (Ft3/Sec) (Ft3/Sec) (Ft3/Sec) 0.00 0 0.00 0.00 0.00 0.23 69 0.40 2.30 2.70 0.73 1,085 2.26 36.17 38.43 1.23 2,100 4.95 70.00 74.95 1.61 3,703 7.42 123.43 130.85 1.98 5,306 10.11 176.87 186.98 Storage Indication Curve 10.00 'O c 0 0 ~ 8.00 ... I. -G> G> u.. 6.00 0 :0 ;:::, 0 -G> O'> 4.00 ... 0 .i:. .~ a 2.00 0 .00 50 .00 200.00 Inflow I Outflow Simulation 2-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0.00 0.00 0.00 0.00 0.00 284.77 0.00 1 0.90 0.99 0.63 0.90 0.13 0.11 284.88 1.00 2 1.79 2.69 2.46 3.32. 0.43 0.24 285.01 1.48 3 2.69 4.48 5.70 6.94 0.62 0.31 285.08 1.67 4 3.59 6.28 10.21 11.97 0.88 0.39 285.16 1.87 5 4.48 8.07 15.85 18.28 1.21 0.48 285.25 2.08 6 5.38 9.87 22.52 25.72 1.60 0.58 285.35 2.28 7 6.28 11.66 30.09 34.17 2.04 0.68 285.45 2.48 8 7.17 13.45 38.26 43.54 2.64 0.81 285.58 2.70 9 8.07 15.25 46.76 53.51 3.37 0.95 285.72 2.93 10 8.97 17.04 55.54 63.80 4.13 1.09 285.86 3.13 11 8.52 17.49 63.41 73.03 4.81 1.21 285.98 3.30 12 8.07 16.59 69.65 80.00 ~ 5.17" 1.27 286.04 3.38 13 7.62 15.69 74.53 85.35 5.41 1.30 286.07 3.43 14 7.17 14.80 78.15 89.32 5.59 1.33 286.10 3.46 15 6.73 13.90 80.64 92.05 5.71 1.35 286.12 3.49 16 6.28 13.00 82.10 93.65 5.78 1.36 286.13 3.50 17 5.83 12.11 82.60 94.20 @ 1.37 286.14 3.51 18 5.38 11.21 82.25 93.81 5.78 1.36 286.13 3.50 19 4.93 10.31 81.10 92.56 5.73 1.36 286.13 3.49 20 4.48 9.42 79.24 90.52 5.64 1.34 286.11 3.47 21 4.04 8.52 76.73 87.76 5.52 1.32 286.09 3.45 22 3.59 7.62 73.62 84.35 5.37 1.30 286.07 3.42 23 3.14 6.73 69.97 80.35 5.19 1.27 286.04 3.38 24 2.69 5.83 65.82 75.80 4.99 1.24 286.01 3.34 25 2.24 4.93 61.47 70.75 4.64 1.18 285.95 3.26 26 1.79 4.04 56.99 65.50 4.26 1.11 285.88 3.16 27 1.35 3.14 52.41 60.13 3.86 1.04 285.81 3.06 28 0.90 2.24 47.73 54.65 3.46 0.97 285.74 2.95 29 0.45 1.35 42.98 49.08 3.05 0.89 285.66 2.83 30 0.00 0.45 38.17 43.43 2.63 0.81 285.58 2.70 Inflow /Outflow Simu lation 2-Year Storm Even t 14 .00 I '\. ' I ' ' 12.00 I ' • ' I ' -"O I c 10 .00 0 ~ Cl) ... Q) Q.. 8.00 i ..... 0 :0 6.00 j (.) -~ 0 !§ 4.00 0 2.00 0.00 0 5 10 15 20 25 30 Ti me (M inute s) Pre-----Post-Post--• -• -• Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt "Free- Hydrograph Hydrograph With Flow' Without Detention Detention Inflow I Outflow Simulation 5-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0 .00 0.00 0.00 0.00 0.00 0 .00 284.77 0 .00 1 1 .09 1 .09 0.77 1.09 0.16 0.13 284 .90 1 .06 2 2 .18 3 .27 3.10 4.04 0.47 0 .26 285 .03 1.52 3 3 .27 5.45 7.14 8.55 0.71 0.34 285.11 1.74 4 4 .36 7 .63 12.71 14.77 1.03 0.43 285.20 1.97 5 5.45 9 .81 19.66 22 .53 1.43 0.54 285.31 2.20 6 6.54 12.00 27.83 31.65 1.91 0.65 285.42 2.42 7 7.63 14.18 36.96 42.01 2.53 0.79 285 .56 2 .66 8 8 .72 16.36 46.59 53.31 3.36 0.95 285 .72 2.92 9 9 .81 18 .54 56.68 65.13 4.23 1 .11 285.88 3.16 10 10.91 20 .72 67.28 77.40 5.06 1.25 286.02 3 .35 11 10.36 21.27 77.44 88.54 5.55 1.33 286 .10 3.46 12 9.81 20.17 85.71 97.61 5.95 1.39 286 .16 3.54 13 9 .27 19.08 92.26 104.80 6.27 1.44 286 .21 3.60 14 8.72 17.99 97.24 110.26 6.51 1.48 286 .25 3.64 15 8 .18 16.90 100.79 114.14 6 .68 1.50 286.27 3 .68 16 7 .63 15.81 103.02 116.60 1.52 ~ 3 .70 17 7.09 14.72 104.07 117.75 1.53 3 .71 18 6.54 13.63 104.03 117.70 1.52 9 3 .70 19 6 .00 12.54 103.00 116.57 1.52 286.29 3.70 20 5.45 11.45 101.06 114.45 1.50 286 .27 3.68 21 4 .91 10.36 98 .30 111.42 6.56 1.48 286.25 3.65 22 4.36 9 .27 94.79 107.57 6.39 1.46 286 .23 3.62 23 3 .82 8.18 90.60 102.97 6.19 1.43 286.20 3.58 24 3.27 7.09 85.78 97.69 5.95 1.39 286.16 3.54 25 2 .73 6.00 80.39 91.78 5.69 1.35 286 .12 3.49 26 2.18 4.91 74.48 85.30 5.41 1.30 286.07 3.43 27 1.64 3.82 68.10 78.30 5 .10 1.25 286.02 3 .36 28 1.09 2.73 61.53 70.83 4.65 1.18 285.95 3.26 29 0.55 1.64 55.00 63.17 4.08 1.08 285.85 3.12 30 0.00 0.55 48.50 55.54 3.52 0.98 285 .75 2 .97 Inflow /Outflow Simulation 5 -Year Storm Event 18.00 I 16 .00 I I 14 .00 I ... -• "O c I 0 ~ 12.00 ... G> G. 10 .00 -G> G> ~ 0 :0 8.00 ::::J 0 -~ 6 .00 0 =§ 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre-----Post-Post--....... Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrog raph Hydrograph With Flow' Without Detention Detention Inflow I Outflow Simulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0 .00 0.00 0.00 0 .00 0.00 0 .00 284.77 0.00 1 1.22 1.22 0.86 1.22 0.18 0 .14 284.91 1.11 2 2.45 3.67 3 .54 4.53 0 .50 0 .27 285.04 1.55 3 3 .67 6.12 8.13 9.66 0.76 0.35 285.12 1.78 4 4.90 8.57 14.44 16.70 1.13 0.46 285.23 2.03 5 6 .12 11.02 22.28 25.46 1.59 0.58 285.35 2.28 6 7.34 13.46 31.50 35.75 2 .12 0 .70 285.47 2.51 7 8.57 15.91 41 .56 47.41 2.92 0.87 285 .64 2.79 8 9.79 18.36 52.23 59.92 3.85 1.04 285.81 3.06 9 11.02 20.81 63.42 73.04 4.81 1.21 285.98 3.30 10 12.24 23.26 75.74 86.67 5.47 1.31 286 .08 3.44 11 11.63 23.87 87.53 99.60 6.04 1.40 286.17 3.55 12 11.02 22.64 97.16 110.17 6.50 1.48 286.25 3.64 13 10.40 21.42 104.83 118.58 6.88 1.53 286 .30 3.71 14 9.79 20.20 110.71 125.03 1.57 286.34 3.76 15 9.18 18.97 114.96 129.69 1.60 286.37 3.80 16 8.57 17.75 117.70 132.70 1.62 286.39 3.82 17 7.96 16.52 119.06 134.22 1.63 e 3.83 18 7.34 15.30 119.20 134.36 1.63 3 .84 19 6.73 14.08 118.21 133.27 7 .53 1.63 0 3.83 20 6.12 12.85 116.21 131.06 7.43 1.61 286.38 3.81 21 5.51 11.63 113.27 127.84 7.28 1.59 286.36 3 .78 22 4.90 10.40 109.48 123.68 7.10 1.56 286.33 3 .75 23 4.28 9.18 104.90 118.66 6.88 1.53 286.30 3.71 24 3.67 7.96 99.61 112.86 6.62 1.49 286.26 3.67 25 3.06 6.73 93.67 106.34 6 .34 1.45 286.22 3.61 26 2.45 5 .51 87.14 99.18 6.02 1.40 286.17 3 .55 27 1.84 4.28 80.07 91.43 5.68 1.35 286.12 3.48 28 1.22 3 .06 72.51 83.13 5.31 1.29 286.06 3.41 29 0.61 1.84 64.53 74.34 4.91 1.22 285 .99 3 .32 30 0.00 0.61 56.68 65.14 4 .23 1.11 285.88 3.16 Inflow/Outflow Simulation 10-Year Storm Event 20 .00 I ' 18.00 I I 16.00 I -• "O c 14.00 0 ~ "> ... 12.00 G> Q. 1 10.00 u. 0 :0 :::J 8.00 0 -~ 0 =§ 6.00 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre----. Post -Post-..... -.. Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrograph Hydrograph With Flow' Without Detention Detention Inflow I Outflow Simulation 25-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0 .00 0 .00 0 .00 0.00 0.00 284.77 0.00 1 1.40 1.40 0 .98 1.40 0.21 0 .15 284.92 1.16 2 2.80 4.19 4 .12 5 .18 0 .53 0.28 285.05 1.58 3 4 .19 6.99 9 .43 11.11 0.84 0 .38 285 .15 1.84 4 5.59 9.79 16.69 19.22 1.26 0.49 285.26 2.11 5 6 .99 12.58 25.70 29 .27 1 .79 0.62 285.39 2 .37 6 8 .39 15.38 36.16 41.08 2 .46 0 .77 285.54 2 .63 7 9 .79 18.17 47.47 54 .33 3.43 0 .96 285.73 2.95 8 11 .18 20.97 59.49 68.43 4.47 1.15 285 .92 3.22 9 12.58 23.77 72.62 83.26 5 .32 1 .29 286.06 3.41 10 13.98 26.56 87.14 99.18 6 .02 1.40 286.17 3.55 11 13.28 27.26 101.02 114.40 6 .69 1 .50 286.27 3 .68 12 12.58 25.86 112.40 126.88 7.24 1 .58 286.35 3.78 13 11.88 24.46 121.46 136.87 7.70 1 .65 286.42 3.86 14 11.18 23.07 128.38 144.52 8.07 1.70 286.47 3.92 15 10.48 21.67 133.37 150.05 8.34 1 .74 286.51 3 .96 16 9.79 20.27 136.62 153.64 8.51 1 .76 286.53 3.99 17 9 .09 18.87 138.29 155.49 ~ 1 .78 e 4 .00 18 8 .39 17.47 138.54 155.76 1.78 4 .00 19 7.69 16.08 137.50 154.61 6 1.77 3.99 20 6 .99 14 .68 135.30 152.18 8 .44 1.76 286.53 3.97 21 6.29 13.28 132.04 148.58 8 .27 1.73 286 .50 3.95 22 5.59 11 .88 127.84 143.92 8.04 1.70 286.47 3.91 23 4.89 10.48 122.77 138.32 7.77 1.66 286.43 3 .87 24 4.19 9 .09 116.93 131.86 7.46 1.62 286.39 3.81 25 3.49 7.69 110.34 124.62 7.14 1.57 286.34 3.76 26 2.80 6 .29 103.05 116.63 6.79 1.52 286.29 3.70 27 2.10 4 .89 95.13 107.94 6.41 1.46 286.23 3.63 28 1.40 3.49 86.64 98.63 6.00 1.40 286.17 3 .55 29 0.70 2 .10 77.61 88.73 5 .56 1.33 286.10 3.46 30 0 .00 0 .70 68.11 78.31 5.10 1.25 286.02 3.36 Inflow/Outflow Simulation 25-Year Storm Event 25.00 I ' I '-20 .00 . ' 0 5 10 15 20 25 30 Time (Minutes) Pre-----Post-Post ---------Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrograph Hydrograph With Flow' Without Detention Detention Inflow I Outflow Simulation 50-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (FVSec) 0 0 .00 0.00 0.00 0.00 0 .00 0 .00 284.77 0.00 1 1.58 1.58 1.11 1.58 0.23 0.16 284.93 1.20 2 3 .16 4.74 4.72 5.85 0 .56 0.29 285.06 1.61 3 4 .74 7.90 10.79 12.62 0.92 0.40 285.17 1.90 4 6 .32 11.06 19.05 21.85 1.40 0.53 285.30 2.18 5 7 .90 14.22 29.28 33.27 2.00 0.67 285.44 2.46 6 9.48 17.38 40.93 46.67 2.87 0.86 285.63 2.77 7 11.06 20.54 53.55 61.47 3.96 1.06 285.83 3.09 8 12.64 23.70 67.15 77.26 5.05 1.25 286.02 3.35 9 14.22 26.86 82.43 94.01 5.79 1.37 286.14 3.51 10 15.80 30.03 99.25 112.46 6.60 1.49 286.26 3.66 11 15.01 30.82 115.30 130.06 7.38 1.60 286.37 3.80 12 14.22 29.24 128.39 144.53 8.07 1.70 286.47 3.92 13 13.43 27.66 138.79 156.04 8 .63 1.78 286.55 4.00 14 12.64 26.07 146.76 164.86 9.05 1.84 286.61 4.07 15 11.85 24.49 152.54 171.26 9.36 1.88 286.65 4.11 16 11.06 22 .91 156.34 175.46 9.56 1.91 286.68 4.14 17 10.27 21.33 158.34 177.67 ~ 1.92 4.16 18 9.48 19.75 158.72 178.09 1.92 4.16 19 8.69 18.17 157.64 176.89 6 3 1.92 4.15 20 7.90 16.59 155.23 174.23 9.50 1.90 4.13 21 7.11 15.01 151.62 170.24 9.31 1.87 4 .11 22 6.32 13.43 146.94 165.05 9.06 1.84 286.61 4.07 23 5.53 11.85 141.27 158.79 8.76 1.80 286.57 4.02 24 4.74 10.27 134.72 151.54 8.41 1.75 286.52 3.97 25 3.95 8.69 127.37 143.41 8.02 1.70 286.47 3 .91 26 3.16 7 .11 119.31 134.49 7.59 1.64 286.41 3 .84 27 2 .37 5 .53 110.53 124.84 7.15 1.57 286.34 3.76 28 1.58 3.95 101.10 114.49 6 .69 1.50 286.27 3 .68 29 0 .79 2.37 91.05 103.47 6.21 1.43 286 .20 3.59 30 0.00 0.79 80.45 91.84 5.70 1.35 286.12 3.49 -'O c 0 ~ 25 .00 20.00 l 15.00 l u.. 0 :0 ::J ~ 10.00 ~ !§ 0 5.00 0.00 Inflow/Outflow Simulation 50 -Year Storm Event • I • I I • • 0 5 10 15 20 25 30 Time (Minutes) Pre-----Post-Post--....... Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt "Free- Hydrograph Hydrograph With Flow· Without Detention Detention Inflow I Outflow Simulation 100-Y ear Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0 .00 0 .00 0.00 0.00 0.00 0.00 284.77 0 .00 1 1.65 1 .65 1.16 1 .65 0.24 0.17 284.94 1.22 2 3 .30 4 .95 4 .95 6 .11 0.58 0 .29 285 .06 1.63 3 4.95 8 .25 11 .31 13.20 0 .95 0.41 285.18 1.92 4 6 .60 11.55 19.95 22 .86 1.45 0 .54 285 .31 2.21 5 8.25 14.85 30.65 34.80 2 .07 0 .69 285.46 2.49 6 9 .90 18.15 42 .75 48.80 3 .03 0.89 285.66 2.82 7 11 .55 21.45 55.88 64.20 4 .16 1.10 285.87 3.14 8 13.20 24.75 70.22 80.63 5 .20 1.27 286.04 3.38 9 14.85 28.05 86 .31 98.27 5.98 1 .39 286.16 3.54 10 16.50 31.35 103.99 117.66 6 .83 1 .52 286.29 3.70 11 15.67 32 .17 120.83 136.17 7.67 1.65 286.42 3 .85 12 14.85 30.52 134.55 151.35 8.40 1 .75 286 .52 13 14.02 28.87 145.46 163.42 8 .98 1.83 286 .60 14 13.20 27 .22 153 .83 172.68 9.43 1 .89 286 .66 15 12.37 25.57 159 .91 179 .41 9 .75 1 .93 286.70 16 11.55 23.92 163.91 183 .83 9 .96 1 .96 286.73 17 10.72 22 .27 166 .03 186.18 ~ 1 .97 e 18 9.90 20 .62 166.46 186 .66 1.98 1 19 9.07 18.97 165.36 185.43 4 1 .97 4 . 4.21 20 8.25 17.32 162 .87 182.68 9.91 1.95 286.72 4 .19 21 7.42 15.67 159 .13 178.54 9.71 1 .93 286.70 4.16 22 6 .60 14.02 154.25 173.15 9.45 1.89 286.66 4.13 23 5 .77 12.37 148.36 166.63 9.14 1.85 286.62 4.08 24 4 .95 10.72 141 .54 159 .08 8.77 1.80 286 .57 4 .03 25 4.12 9.07 133.88 150.61 8.37 1.74 286.5 1 3 .96 26 3 .30 7.42 125.47 141.31 7.92 1 .68 286.45 3.89 27 2.47 5.77 116.37 131 .24 7.43 1 .61 286 .38 3.81 28 1 .65 4.12 106.58 120.50 6 .96 1 .54 286 .31 3.73 29 0.82 2.47 96 .15 109.06 6.46 1.47 286.24 3.63 30 0 .00 0 .82 85.13 96.97 5.92 1.39 286.16 3 .53 Inflow/Outflow Simulation 100-Year Storm Event 30 .00 25.00 ' I '" ' I ' -I ,, ' c I ' 0 • '" g 20.00 Cl) ... Q) Q.. G> Q) 15.00 u.. 0 :0 ;:, u -~ 10.00 0 =§ 0 5.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre -----Post -Post -.... -... Post - Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrograph Hydrograph With Flow' Without Detention Detention Inflow/Outflow Simulation 2 -Year Storm Ev ent 10 .00 9.00 8.00 -,, 7.00 c 0 0 G> Cl) 6.00 .. G> Q. -; G> 5.00 u.. 0 :0 ;::, 0 4.00 -~ 0 =§ 3.00 0 2.00 l.00 0 .00 0 5 10 15 20 25 30 Ti me (Minutes ) Pre-Development Hydrograph ---Tota l Post-Development Hydrograph Inflow/Outflow Simulation 5-Year Storm Event -10.00 "O c 0 ~ ... G> 8.00 a.. 1 LI.. 0 :0 6.00 :I () -~ 0 =§ 0 4.00 0 5 10 15 20 25 30 Time (Minutes) Pre-Development Hydrograph ---Total Post-Development Hydrograph Inflow/Outflow Simulation 10-Yeor Storm Event 14.00 12.00 -10.00 "O c 0 ~ Cl) ... G> 8.00 Q. 1 ..... 0 :0 6.00 :J (.) -~ 0 !§ 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) ---Pre -Development Hydrograph ---Total Post-Development Hydrograph Inflow /Outflow Simulation 25-Year Storm Event 12.00 -"O c 0 ~ 10 .00 ... G> Q. -$ 8.00 u.. 0 :0 ;, g ~ 6.00 0 ~ 0 4 .00 0 5 10 15 20 25 30 Ti me (Minutes ) Pre-Development Hydrograph ----Total Post -Development Hydrograph Inflow/Outflow Simulation 50 -Year Storm Event 14 .00 -"O c 0 12.00 ~ Cl) ... G> Q. 10 .00 l u.. 0 :0 8.00 ::1 0 -~ 0 6 .00 !§ 0 4 .00 0 5 10 15 20 25 30 Time (Minutes) ---Pre-Development Hydrograph ---To t al Post-Development Hydrograph Inflow /Outflow Simulation 100 -Year Storm Even t 20 .00 18 .00 16.00 -'O 14.00 c 0 ~ 12.00 ... G> 0... i 10.00 ...... 0 :0 ::;, 0 8.00 -~ 0 !§ 6.00 0 4.00 2.00 0.00 0 5 10 15 20 25 30 n me (M inute s) ---Pre-Development Hydrograph ---Total Post-Development Hydrograph DRAINAGE COMPUTATIONS For A Replat Of Tract 11 8 11 , Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas Prepared By : Garrett Engineering 4444 Carter Creek Parkway -Suite 108 Bryan, Texas 77802 Telephone : ( 409) 846-2688 DRAINAGE COMPUTATIONS For A Rep lat of Tract "B ", Block 55 Southwood Valley -Section 24A College Station, Brazos County, Texas *September, 1994 * SUMMARY The project is situated adjacent to Welsh Ave., and south of San Mario Ct. in Southwood Valley, College Station, Brazos County, Texas . Tract "B", Block 55 of Southwood Valley -Section 24A consists of 15 lots, these 15 lots being established within the bounds of a 3.93 acre tract. The total drainage area tributary to the project is 3.93 acres. The pre-development run-off coefficient was estimated to be 0.40, while taking into account typical residential site improvements would result in a post-development run-off coefficient of 0 .56 . A detention facility will be constructed in the northwest corner of the property as designated on the plat. The detention pond is designed to facilitate up to and including the 100-year storm event, and discharge at a rate less than the current pre-development peak discharge rate. The detention pond will intercept, store and meter run-off from 2.50 acres of the project. The run-off generated on the remaining 1.43 acres will "free-flow" across the project site unmetered off the property . From the computations on page 1, based on the total tributary drainage area of the project being estimated at 3.93 acres, the pre-development run-off coefficient being assumed at 0.40, and a minimum time of concentration of 10 minutes, the relative pre-development peak discharge rate ("Q") was determined. The Rational Method was utilized to compute the estimated peak pre-development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA. "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off coefficient, assumed to be 0.40 in the pre-development condition, "I" is the storm intensity in inches per hour, and "A" is the area of the drainage basin in acres. From the computations on page 2, based on the tributary area of 3.93 acres, the post-development run-off coefficient being assumed at 0.56, and a minimum time of concentration of 10 minutes, the relative pre- development peak discharge rate ("Q") was determined assuming the same minimum time of concentration of 10 minutes. The Rational Method was again utilized to compute the estimated peak post- development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA, where; "Q" is the peak discharge rate in cubic feet per second. "C" is the run-off coefficient, in the post- development condition "C" is assumed to be 0 .56, "I" is the storm intensity in inches per hour and "A" is the area of the basin in acres . The comparison between the peak pre-development discharge rate and post-development discharge rate is included as an aid to the designer to establish a preliminary "target" for the necessary volume in the proposed detention facility. This preliminary estimate is found by simply determining the volume generated from the difference between the pre-development and post-development hydrographs (see pages 9-11 for pre-development and post-development hydrographs). Please note that the post-development hydrograph shown on these same graphs assumes no detention. Page 3 and page 4 provide computations that determine the post-development run-off that is not routed through the detention facility ("free-flow") and post-development run-off that is routed through the detention facility . Page 5 and page 6 are tabulations of the pre-development hydrograph and the post-development hydrograph based on the computations performed on page 1 and page 2. The post-development hydrograph assumes no detention to facilitate direct comparison in the pre-and post-development conditions. Page 7 and page 8 are tabulations of the post-development hydrograph for run-off directed through the detention facility and the post-development hydrograph for "free-flow" from the project site. Computations on page 4 determine the actual peak post-development "inflow" rate supplied to the proposed detention facility. From this "inflow" rate and the time of concentration (10 minutes minimum), a hydrograph as tabulated on page 8 can be derived. The hydrograph is triangular in shape and is based on the standard SCS unit hydrograph with time to peak set equal to the time of concentration and the total time base set at 3.00 times the time of concentration. Please note that a 30 minute total storm event duration was utilized exclusively throughout this report due totally to the small physical size of the project Having derived the preliminary volume requirements and "allowable peak" discharge rate, it is now possible to design the final detention facility and outlet control structure. Page 12 presents a tabulation and a depth versus volume graph of the detention facility. The maximum depth of the pond was set at 1.98' (top retaining wall less flow line "out" of outlet control structure: 286.75' -284.77' = 1.98'). Page 13 supplies a tabulation and a rating curve for the proposed outlet control structure. A rectangular weir was decided upon due to depth verses discharge ratio characteristics associated with the anticipated shallow headwater depth (maximum of 1.98') and the fixed weir width of 1.21' (1'-2-1/2"). The equation used to determine discharge was Q = CLH3/2 where "Q" is the discharge rate in cubic feet per second. "C" is the coefficient of discharge, in this case assumed to be set at 3.000. "L" is the width of the weir in feet, in this case assumed to be set at 1.21'. "H" is the headwater depth in feet (ranges from O' to a maximum of 1.98'). Page 14 presents a tabulation of the relationship between discharge from the detention facility and the dimensionless quantity 2S/t-O. Also presented is a Storage Indication Curve for the detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrograph, and rating curve for the outlet structure. The storage indication curve as shown on page 12 is a graphical solution to the equation presented in the "Drajna2e Policy And Desi2n Standards" as follows: 2s1 (I 1 + 12) + (----------------01) = dt 2s2 (-----------------+ 02) dt Page 15 through page 26 present simulations of the 2, 5, 10, 25, 50, and 100 year storm events. The first page of each storm simulation represents the tabulated data for the storm event. The maximum depth achieved in the detention pond during each simulation is shown below as is the time period during which this maximum depth occurs after the beginning of the storm event. The calculated peak discharge rate corresponding to this depth over same period is also shown below. Additionally, the maximum water surface elevation achieved during each event and the maximum peak discharge during each event are listed below. The second page of each storm simulation represents the pre-development hydrograph, the post-development hydrograph (with no detention), the post-development hydrograph as routed through the detention pond, and post-development "free-flow" hydrograph for each storm event Storm Max Depth (Year) (Ft) 2-year 1.37 5-year 1.53 10-year 1.63 25-year 1.78 50-year 1.92 100-yearl.98 Time Period (Min) 17 17 17-19 17-18 17-19 18 Max Discharge Max Elev (CFS) (Ft MSL) 5.80 286.14 6.84 286.30 7.58 286.40 8.61 286.55 9.69 286.69 10.10 286.75 Max Velocity (Ft/Sec) 3.51 3.71 3.84 4.00 4.16 4.22 Page 27 through page 32 provide total inflow/outflow hydrographs for the 2, 5, 10, 25, 50 and 100-year pre-development and post-development storm events. It can be determined from these same hydrographs that the post-development peak discharge rates have been minutely decreased from those peak pre- development discharge rates due to the incorporation of the detention facility in the post-development condition. Total post-development peak discharge rates from the detention pond outlet control structure and project site are kept less than the pre-development peak discharge rates due to the incorporation of the proposed detention facilities. Subsequent peak post-development discharge velocities projected to be within manageable limits. Determine Total Pre-Development Peak Storm Water Discharge Rates Tributary Area ("A"): 3.93 Acres Pervious Area : 3 .93 Acres Impervious Area : 0.00 Acres Run-Off Coefficient ("Cwt"): 0.40 Time Of Concentration ("T/c"): Woodlands: Low Elevation : High Elevation: Distance (Feet): Slope (%Grade): Velocity ("Vw"): Time : Pastures: Low Elevation : High Elevation : Distance (Feet): Slope (% Grade): Velocity ("Vp "): Time : Pavements: Low Elevation : High Elevation : Distance (Feet): Slope (% Grade): Velocity ("Vpave"): Time: Total Travel Time: Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11 .64 Peak Discharge Rate ("Q"): 2-Year: 9.95 5-Year: 12.09 10-Year: 13 .57 25-Year: 15 .50 50-Year: 17.52 100-Year: 18.30 C= 0.40 C= 0 .98 0.00 0.00 0.00 0 .00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0 .00 Minutes 0.00 0 .00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 10.00 Minutes Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determine Post-development Peak Storm Water Dischar e No Detention Tributary Area ("A"): 3.93 Acres Pervious Area: 2.84 Acres C= 0.40 C= 0.98 Impervious Area : 1.09 Acres Run-Off Coefficient ("Cwt"): 0.56 Time Of Concentration ("T/c"): 10 Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches I Hour 5-Year: 7 .69 Inches I Hour 10-Year: 8.63 Inches I Hour 25-Year: 9.86 Inches I Hour 50-Year: 11 .15 Inches I Hour 100-Year: 11 .64 Inches I Hour Peak Discharge Rate ("Q"): 2-Year: 13.94 Cubic Feet I Second 5-Year: 16.96 Cubic Feet I Second 10-Year: 19 .03 Cubic Feet I Second 25-Year: 21 .74 Cubic Feet I Second 50-Year: 24 .57 Cubic Feet I Second 100-Year: 25.66 Cubic Feet I Second Comparison Of Predeve lo pment And Post-develo ment Peak Dischar e Rates Predevelopment 2-Year: 9.95 Ft3/sec 5-Year: 12.09 Ft3/sec 10-Year: 13.57 Ft3/sec 25-Year: 15.50 Ft3/sec 50-Year: 17.52 Ft3/sec 100-Year: 18 .30 Ft3/sec Preliminary Determination Of Detention Pond Vo lume Post-Development 13 .94 Ft3/sec 16 .96 Ft3/sec 19 .03 Ft3/sec 21.74 Ft3/sec 24.57 Ft3/sec 25.66 Ft3/sec Increase 4.00 Ft3/sec 4 .86 Ft3/sec 5.46 Ft3/sec 6.23 Ft3/sec 7.05 Ft3/sec 7.36 Ft3/sec 2-Year: 4.00 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 3 ,600 Cubic Feet 5-Year: 4.86 Ft3/sec x (30 Min . x 60 Sec . I 2 ) = 4,377 Cubic Feet 10-Year: 5.46 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 4,913 Cubic Feet 25-Year: 6.23 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 5,611 Cubic Feet 50-Year: 7 .05 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 6,343 Cubic Feet 100-Year: 7.36 Ft3/sec x (30 Min. x 60 Sec . I 2 ) = 6,622 Cubic Feet Determine Post-Development 11 Free-Flow 11 Peak Storm Water Discharge Tributary Area ("A"): 1.43 Acres Pervious Area : 1.00 Acres Impervious Area : 0.43 Acres Run-Off Coefficient ("Cwt"): 0.57 Time Of Concentration ("T/c"): 1 O Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7 .69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 5.20 5-Year: 6.32 10-Year: 7.09 25-Year: 8.10 50-Year: 9.16 100-Year: 9.56 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Determine Post-Development Flow Into Detention Pond Tributary Area ("A"): 2 .50 Acres Pervious Area : 1.78 Acres Impervious Area: 0.72 Acres Run-Off Coefficient ("Cwt"): 0.57 Time Of Concentration ("T/c"): 1 O Minutes (Min) Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11.15 100-Year: 11.64 Peak Discharge Rate ("Q "): 2-Year: 8.97 5-Year: 10.91 10-Year: 12.24 25-Year: 13.98 50-Year: 15.80 100-Year: 16.50 C= 0.40 C= 0.98 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Pre-Development Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year {Minutes} Storm Storm Storm Storm Storm Storm 0 0.00 0 .00 0 .00 0 .00 0 .00 0.00 1 0.99 1.21 1.36 1.55 1.75 1.83 2 1.99 2.42 2.71 3.10 3.50 3.66 3 2 .98 3.63 4.07 4.65 5.26 5.49 4 3.98 4 .84 5.43 6.20 7.01 7.32 5 4.97 6 .05 6.79 7.75 8.76 9.15 6 5 .97 7.26 8.14 9.30 10.51 10 .98 7 6 .96 8.47 9.50 10.85 12.27 12 .81 8 7.96 9 .67 10.86 12.40 14.02 14.64 9 8 .95 10.88 12.22 13.95 15.77 16.47 Peak=> 10 9.95 12.09 13.57 15.50 17.52 18.30 11 9.45 11.49 12.89 14.73 16.65 17.38 12 8.95 10.88 12.22 13.95 15 .77 16.47 13 8 .45 10.28 11 .54 13.18 14.90 15.55 14 7.96 9.67 10.86 12.40 14.02 14.64 15 7.46 9 .07 10.18 11.63 13.14 13.72 16 6.96 8.47 9.50 10.85 12.27 12.81 17 6.46 7.86 8 .82 10.08 11.39 11.89 18 5.97 7 .26 8.14 9.30 10.51 10.98 19 5.47 6 .65 7.47 8.53 9.64 10.06 20 4 .97 6 .05 6.79 7.75 8 .76 9.15 21 4.48 5.44 6.11 6 .98 7.89 8 .23 22 3.98 4.84 5.43 6 .20 7.01 7 .32 23 3.48 4.23 4.75 5.43 6.13 6.40 24 2 .98 3 .63 4.07 4.65 5.26 5 .49 25 2.49 3.02 3.39 3.88 4 .38 4 .57 26 1 .99 2 .42 2.71 3 .10 3.50 3 .66 27 1.49 1.81 2.04 2 .33 2 .63 2.74 28 0.99 1 .21 1.36 1 .55 1.75 1.83 29 0 .50 0.60 0 .68 0.78 0.88 0.91 30 0 .00 0 .00 0.00 0.00 0.00 0.00 Post-Development Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0 .00 0.00 0 .00 0.00 0.00 0.00 1 1.39 1.70 1 .90 2.17 2 .46 2 .57 2 2.79 3.39 3 .81 4.35 4.91 5.13 3 4.18 5.09 5 .71 6 .52 7 .37 7 .70 4 5 .58 6 .78 7.61 8.69 9.83 10.26 5 6 .97 8.48 9 .52 10.87 12.29 12 .83 6 8.37 10.17 11.42 13.04 14.74 15.39 7 9.76 11.87 13.32 15 .22 17.20 17.96 8 11.16 13.57 15.23 17.39 19.66 20.52 9 12.55 15.26 17.13 19.56 22.11 23.09 Peak=> 10 13.94 16.96 19.03 21.74 24.57 25.66 11 13 .25 16.11 18.08 20.65 23 .34 24 .37 12 12.55 15.26 17.13 19.56 22.11 23 .09 13 11.85 14.41 16.18 18.48 20 .89 21.81 14 11.16 13 .57 15.23 17.39 19 .66 20 .52 15 10.46 12.72 14.27 16.30 18.43 19.24 16 9.76 11.87 13.32 15.22 17.20 17.96 17 9 .06 11 .02 12 .37 14.13 15.97 16.68 18 8.37 10.17 11.42 13.04 14.74 15 .39 19 7.67 9 .33 10.47 11.96 13.51 14.11 20 6.97 8.48 9.52 10.87 12.29 12 .83 21 6.28 7.63 8.56 9.78 11.06 11 .54 22 5.58 6 .78 7.61 8.69 9.83 10.26 23 4 .88 5 .93 6.66 7.61 8 .60 8.98 24 4.18 5 .09 5.71 6.52 7.37 7.70 25 3.49 4.24 4.76 5.43 6.14 6.41 26 2.79 3 .39 3.81 4.35 4.91 5.13 27 2.09 2 .54 2.85 3 .26 3.69 3 .85 28 1.39 1.70 1.90 2.17 2.46 2 .57 29 0.70 0 .85 0.95 1.09 1 .23 1 .28 30 0 .00 0.00 0.00 0.00 0 .00 0 .00 Post-Development Flow Routed Through Detention Pond Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.90 1.09 1.22 1.40 1.58 1.65 2 1.79 2.18 2.45 2.80 3.16 3.30 3 2.69 3.27 3.67 4.19 4.74 4.95 4 3.59 4.36 4.90 5.59 6.32 6.60 5 4.48 5.45 6.12 6.99 7.90 8.25 6 5.38 6.54 7.34 8.39 9.48 9.90 7 6.28 7.63 8.57 9.79 11.06 11.55 8 7.17 8.72 9.79 11.18 12.64 13.20 9 8.07 9.81 11.02 12.58 14.22 14.85 Peak=> I 10 8.97 10.91 12.24 13.98 15.80 16.50 11 8.52 10.36 11.63 13.28 15.01 15.67 12 8.07 9.81 11.02 12.58 14.22 14.85 13 7.62 9.27 10.40 11.88 13.43 14.02 14 7.17 8.72 9.79 11.18 12.64 13.20 15 6.73 8.18 9.18 10.48 11.85 12.37 16 6.28 7.63 8.57 9.79 11.06 11.55 17 5.83 7.09 7.96 9.09 10.27 10.72 18 5.38 6.54 7.34 8.39 9.48 9.90 19 4.93 6.00 6.73 7.69 8.69 9.07 20 4.48 5.45 6.12 6.99 7.90 8.25 21 4.04 4.91 5.51 6.29 7.11 7.42 22 3.59 4.36 4.90 5.59 6.32 6.60 23 3.14 3.82 4.28 4.89 5.53 5.77 24 2.69 3.27 3.67 4.19 4.74 4.95 25 2.24 2.73 3.06 3.49 3.95 4.12 26 1.79 2.18 2.45 2.80 3.16 3.30 27 1.35 1.64 1.84 2.10 2.37 2.47 28 0.90 1.09 1.22 1.40 1.58 1.65 29 0.45 0.55 0.61 0.70 0.79 0.82 30 0.00 0.00 0.00 0.00 0.00 0.00 Post-Development "Free-Flow" Storm Intensity Rates (Inches Per Hour) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.52 0.63 0.71 0.81 0.92 0.96 2 1.04 1.26 1.42 1.62 1.83 1.91 3 1.56 1.90 2.13 2.43 2.75 2.87 4 2.08 2.53 2.84 3.24 3.66 3.82 5 2.60 3.16 3.55 4.05 4.58 4.78 6 3.12 3.79 4.26 4.86 5.49 5.74 7 3.64 4.42 4.96 5.67 6.41 6.69 8 4.16 5.06 5.67 6.48 7.33 7.65 9 4.68 5.69 6.38 7.29 8.24 8.60 Peak=> 1·· 10 5.20 6.32 7.09 8.10 9.16 9.56 11 4.94 6.00 6.74 7.70 8.70 9.08 12 4.68 5.69 6.38 7.29 8.24 8.60 13 4.42 5.37 6.03 6.89 7.78 8.13 14 4.16 5.06 5.67 6.48 7.33 7.65 15 3.90 4.74 5.32 6.08 6.87 7.17 16 3.64 4.42 4.96 5.67 6.41 6.69 17 3.38 4.11 4.61 5.27 5.95 6.21 18 3.12 3.79 4.26 4.86 5.49 5.74 19 2.86 3.48 3.90 4.46 5.04 5.26 20 2.60 3.16 3.55 4.05 4.58 4.78 21 2.34 2.84 3.19 3.65 4.12 4.30 22 2.08 2.53 2.84 3.24 3.66 3.82 -23 1.82 2.21 2.48 2.84 3.20 3.35 24 1.56 1.90 2.13 2.43 2.75 2.87 25 1.30 1.58 1.77 2.03 2.29 2.39 26 1.04 1.26 1.42 1.62 1.83 1.91 27 0.78 0.95 1.06 1.22 1.37 1.43 28 0.52 0.63 0.71 0.81 0.92 0.96 29 0.26 0.32 0.35 0.41 0.46 0.48 30 0.00 0.00 0.00 0.00 0.00 0.00 .... Q) a.. -Q) Cl> u.... o-·-"O ..Q c :::I 0 0 0 -Cl> &Cl) .... 0 s:. ~ a 14.00 .... Q) 12.00 a.. i 10.00 u.... o -·-"O 8.00 ..Q c :::I 0 0 0 6.00 -Q) G> Cl) O> .... 4.00 0 s:. ~ 2.00 a 0.00 0 Total Pre -Development Hydrograph Vs. Tota l Post - Development Hydrograph Fo r 2-Year Storm Even t 5 10 15 20 25 nme (Minutes) ---Pre-Development Hydrograph ---Total Post-Development Hydrograph 18.00 16 .00 14.00 12.00 10 .00 8.00 6.00 4.00 2.00 0.00 0 Total Pre-Dev elopment Vs. Total Post -Development (N o Detention) Peak Discharge Rates 5-Year Storm Even t 5 10 15 20 25 Time (Minutes) 30 Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detention 3( ... G> Q.. i u.. o -·-'O ..0 c :I 0 ~~ G> Cl) O> ... 0 .c ~ 0 ... G> Q.. Qi G> u.. o-·-'O ..0 c :I 0 0 0 -G> &Cl) ... 0 .c .~ c 20 .00 18.00 16.00 14.00 12 .00 10 .00 8.00 6.00 4.00 2.00 0.00 0 Total Pre-Development Vs . Total Post-Development (No Detention) Peak Discharge Rates 10-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 Pre-Development Hydrograph ---Post-Developme nt Outflow Hydrograph Without Detention 25.00 20.00 15.00 10 .00 5.00 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 25-Year Storm Event 5 10 15 20 25 Ti me (Minutes) 30 ---Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detention 25.00 ... Q) Q. i 20.00 ~ 0 ...... 15.00 ·-,, ..0 c ::::J 0 ~~ 10.00 & ... 0 s:. 5.00 ~ 0 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 50-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 ---Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detention 30.00 ... Q) Q. 25.00 -$ ~ ...... 20.00 ·-,, ..0 c 8 8 15.00 -Q) Q) Cl) 10.00 O> ... 0 s:. 5.00 ~ 0 0.00 0 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 100-Year Storm Event 5 10 15 20 25 Time (Minutes) 30 Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention Detention Pond De th Vs. Volume Elevati on Depth Volume (Feet) (Ft3) 284.77 0.0 0 0 285 .00 0.23 69 285.5 0 0.73 1,08 5 286.00 1.23 2,100 286 .38 1.61 3,703 286.75 1.98 5 ,3 06 Detention Pond Depth Vs. Volume 2.00 1.80 1.60 1.40 i 1.20 u.. -1.00 ~ Cl> 0 0.80 0 .60 0 .40 0 .20 / / / / ~ / 1/ / / ~ v / / 0.00 0 1,000 2,000 3,000 4,000 5 ,000 6,000 Detention Pond Volume (Cubic Feet) Rating Curve For Outlet Control Structure Weir Length(L): 1.21 (1 '-2-1/2") De th Vs. Volume Elevation Depth Discharge (Feet) Ft3/Sec 284.77 0.00 0.00 285 .00 0 .23 0.40 285 .50 0.73 2.26 286.00 1.23 4.95 286 .38 1.61 7.42 286 .75 1.98 10.11 Rating Curve For Outlet Control Structure Depth Vs. Volume 2.00 1.80 1.60 1.40 i 1.20 u.. -1.00 &. -a. CD 0 0.80 0 .60 0.40 0.20 /~ / v / / ~ v / .J v / / I 0.00 0.00 2 .00 4.00 6.00 8.00 10.00 12.00 Discharge (Cubic Feet Per Second) I Storage Indication Curve Depth Storage Discharge 2s/t 2s/t+O (Feet) (Ft3) (Ft3/Sec) (Ft3/Sec) (Ft3/Sec) 0 .00 0 0.00 0.00 0.00 0.23 69 0.40 2.30 2.70 0 .73 1,085 2 .26 36.17 38.43 1.23 2,100 4.95 70.00 74 .95 1.61 3,703 7.42 123.43 130.85 1.98 5,306 10.11 176.87 186.98 Storage Indication Curve 10.00 '6' c 0 ~ 8 .00 -t. -Cl) Cl) LL. 6.00 0 :0 ::J ~ Q) O> 4.00 -0 .s::. ~ 0 2.00 0.00 50 .00 100 .00 150 .00 200.00 2s/t+O (Cubic Feet Per Second) Inflow I Outflow Simulation 2-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0.00 0.00 0.00 0.00 0.00 284.77 0.00 1 0.90 0.90 0.63 0.90 0.13 0.11 284.88 1.00 2 1.79 2.69 2.46 3.32 0.43 0.24 285.01 1.48 3 2.69 4.48 5.70 6.94 0.62 0.31 285.08 1.67 4 3.59 6.28 10.21 11.97 0.88 0.39 285.16 1.87 5 4.48 8.07 15.85 18.28 1.21 0.48 285.25 2.08 6 5.38 9.87 22.52 25.72 1.60 0.58 285.35 2.28 7 6.28 11.66 30.09 34.17 2.04 0.68 285.45 2.48 8 7.17 13.45 38.26 43.54 2.64 0.81 285.58 2.70 9 8.07 15.25 46.76 53.51 3.37 0.95 285.72 2.93 10 8.97 17.04 55.54 63.80 4.13 1.09 285.86 3.13 11 8.52 17.49 63.41 73.03 4.81 1.21 285.98 3.30 12 8.07 16.59 69.65 80.00 5.17 1.27 286.04 3.38 13 7.62 15.69 74.53 85.35 5.41 1.30 286.07 3.43 14 7.17 14.80 78.15 89.32 5.59 1.33 286.10 3.46 15 6.73 13.90 80.64 92.05 5.71 1.35 286.12 3.49 16 6.28 13.00 82.10 93.65 5.78 1.36 286.13 3.50 17 5.83 12.11 82.60 94.20 5.80 1.37 286.14 3.51 18 5.38 11.21 82.25 93.81 5.78 1.36 286.13 3.50 19 4.93 10.31 81.10 92.56 5.73 1.36 286.13 3.49 20 4.48 9.42 79.24 90.52 5.64 1.34 286.11 3.47 21 4.04 8.52 76.73 87.76 5.52 1.32 286.09 3.45 22 3.59 7.62 73.62 84.35 5.37 1.30 286.07 3.42 23 3.14 6.73 69.97 80.35 5.19 1.27 286.04 3.38 24 2.69 5.83 65.82 75.80 4.99 1.24 286.01 3.34 25 2.24 4.93 61.47 70.75 4.64 1.18 285.95 3.26 26 1.79 4.04 56.99 65.50 4.26 1.11 285.88 3.16 27 1.35 3.14 52.41 60.13 3.86 1.04 285.81 3.06 28 0.90 2.24 47.73 54.65 3.46 0.97 285.74 2.95 29 0.45 1.35 42.98 49.08 3.05 0.89 285.66 2.83 30 0.00 0.45 38.17 43.43 2.63 0.81 285.58 2.70 14.00 12.00 -'O g 10.00 ~ 8 .00 6 .00 4.00 2.00 0.00 Inflow/Outflow Simulation 2-Yeor Storm Event I • I 0 5 Pre----- Develo pm e nt Hydr og ra ph I '\. I 10 " " 15 20 Time (Minutes) Post -Post- Developme Developme nt Outflow nt Outflow Hydrograph With Withou t Detention De t ention 25 30 -• -• -• Post- Devel opme nt "Free- Flow· Inflow I Outflow Simulation 5-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (FVSec) 0 0.00 0.00 0.00 0.00 0.00 0.00 284.77 0.00 1 1.09 1.09 0.77 1.09 0.16 0.13 284.90 1.06 2 2.18 3.27 3.10 4.04 0.47 0.26 285.03 1.52 3 3.27 5.45 7.14 8.55 0.71 0.34 285.11 1.74 4 4.36 7.63 12.71 14.77 1.03 0.43 285.20 1.97 5 5.45 9.81 19.66 22.53 1.43 0.54 285.31 2.20 6 6.54 12.00 27.83 31.65 1.91 0.65 285.42 2.42 7 7.63 14.18 36.96 42.01 2.53 0.79 285.56 2.66 8 8.72 16.36 46.59 53.31 3.36 0.95 285.72 2.92 9 9.81 18.54 56.68 65.13 4.23 1.11 285.88 3.16 10 10.91 20.72 67.28 77.40 5.06 1.25 286.02 3.35 11 10.36 21.27 77.44 88.54 5.55 1.33 286.10 3.46 12 9.81 20.17 85.71 97.61 5.95 1.39 286.16 3.54 13 9.27 19.08 92.26 104.80 6.27 1.44 286.21 3.60 14 8.72 17.99 97.24 110.26 6.51 1.48 286.25 3.64 15 8.18 16.90 100.79 114.14 6.68 1.50 286.27 3.68 16 7.63 15.81 103.02 116.60 6.79 1.52 286.29 3.70 17 7.09 14.72 104.07 117.75 6.84 1.53 286.30 3.71 18 6.54 13.63 104.03 117.70 6.84 1.52 286.29 3.70 19 6.00 12.54 103.00 116.57 6.79 1.52 286.29 3.70 20 5.45 11.45 101.06 114.45 6.69 1.50 286.27 3.68 21 4.91 10.36 98.30 111.42 6.56 1.48 286.25 3.65 22 4.36 9.27 94.79 107.57 6.39 1.46 286.23 3.62 23 3.82 8.18 90.60 102.97 6.19 1.43 286.20 3.58 24 3.27 7.09 85.78 97.69 5.95 1.39 286.16 3.54 25 2.73 6.00 80.39 91.78 5.69 1.35 286.12 3.49 26 2.18 4.91 74.48 85.30 5.41 1.30 286.07 3.43 27 1.64 3.82 68.10 78.30 5.10 1.25 286.02 3.36 28 1.09 2.73 61.53 70.83 4.65 1.18 285.95 3.26 29 0.55 1.64 55.00 63.17 4.08 1.08 285.85 3.12 30 0.00 0.55 48.50 55.54 3.52 0.98 285.75 2.97 18 .00 16 .00 14 .00 -"O c 0 0 12.00 ~ ... Cl> ~ 10 .00 -$ u. 0 :0 8 .00 ::::J 0 -~ 6 .00 0 5 ::::J 0 4.00 2.00 0.00 Inflow /Outflo w Simulation 5 -Yeor Storm Even t I • I I 0 5 Pre----- Developme nt Hydrograph I I '- I '- 10 " " 15 20 Ti me (M inutes) Post-Post- Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 25 ........ 30 Post- Developme nt 'Free- Flow' Infl ow I Outflow Si mulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outfl ow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0 .00 0.00 0.00 0 .00 0 .00 284 .77 0 .00 1 1.22 1.22 0.86 1.22 0 .18 0.14 2 84 .9 1 1.11 2 2.45 3 .67 3.54 4 .53 0 .50 0 .27 285 .04 1 .55 3 3.67 6 .12 8.13 9.66 0.76 0.35 285 .12 1 .78 4 4 .90 8 .57 14.44 16.70 1.13 0.46 285 .23 2 .03 5 6.12 11.02 22 .28 25.46 1.59 0.58 285.35 2 .28 6 7 .34 13.46 31 .50 35 .75 2 .12 0.70 285.47 2 .51 7 8 .57 15 .91 41 .56 47.41 2.92 0.87 285.64 2 .79 8 9 .79 18.36 52 .23 59 .92 3.85 1.04 285.81 3 .06 9 1 1.02 20.8 1 63.42 73 .04 4 .81 1.21 285 .98 3 .30 10 12 .24 23.26 75 .74 86 .67 5.47 1 .31 286.0 8 3.44 11 11 .63 23 .87 87.53 99 .60 6 .04 1.40 286.1 7 3 .55 12 11 .02 22 .64 97.16 1 10.17 6 .50 1.48 286.25 3.64 13 10.40 21.42 104 .83 1 18 .58 6 .88 1 .53 286 .30 3 .71 14 9.79 20 .20 110.71 125 .03 7 .16 1 .57 286.34 3.76 15 9 .18 18.97 114 .96 129 .69 7 .36 1.60 2 86 .37 3 .80 16 8.57 17.75 117.70 132.70 7 .50 1 .62 286 .39 3.82 17 7 .96 16.52 119.06 134 .22 7 .58 1 .63 286.40 3.83 18 7 .34 15 .30 119 .20 134.36 7 .58 1 .63 286.40 3 .84 19 6 .73 14 .08 118 .21 133 .27 7 .53 1 .63 286.40 3 .83 20 6.12 12 .85 116.21 13 1 .0 6 7.43 1 .61 286.38 3 .81 21 5 .51 11 .63 113.27 127.84 7.28 1 .59 286 .36 3 .78 22 4.90 10.40 109.48 123.68 7 .10 1 .56 286 .33 3.75 23 4 .28 9 .18 104.90 118.66 6.88 1 .53 286.30 3 .71 24 3 .67 7 .96 99 .61 112.86 6 .62 1 .49 286.26 3 .67 25 3 .06 6 .73 93.67 106.34 6 .34 1.45 286 .22 3.61 26 2.45 5 .51 87.14 99 .18 6.02 1.40 286 .17 3.55 27 1 .84 4 .28 80.07 91.43 5 .68 1.35 286 .12 3.48 28 1.22 3 .06 72 .51 83.13 5 .31 1.29 286 .06 3.4 1 29 0.61 1 .84 64.53 74 .34 4 .91 1 .22 285.99 3.32 30 0 .00 0 .61 56.68 65 .14 4 .23 1 .11 285.88 3 .16 20 .00 18 .00 16.00 -,, c 14 .00 0 ~ -12.00 G> A. -$ 10 .00 ""' 0 :0 :J 8.00 0 -~ 0 !§ 6 .00 0 4 .00 2.00 0.00 Inflow /Outflow Simulation 10-Yea r Storm Even t I I • 0 5 Pre----- Developme nt Hydrograph I '- I 10 " " 15 20 Ti me (Minutes) Post-Post- Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 25 .. -... -. 30 Post- Developme nt 'Free- Flow ' Inflow I Outflow Simulation 25-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes} (Ft3/Sec} (Ft3/Sec} (Feet} (FVSec} 0 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 284 .77 0 .00 1 1.40 1.40 0 .98 1 .40 0.21 0.15 284.92 1.16 2 2 .80 4.19 4.12 5.18 0 .53 0.28 285 .05 1.58 3 4.19 6.99 9.43 11.11 0 .84 0 .38 285.15 1.84 4 5.59 9.79 16.69 19 .22 1 .26 0.49 285.26 2.11 5 6 .99 12.58 25 .70 29 .27 1 .79 0 .62 285.39 2 .37 6 8.39 15 .38 36.16 41 .08 2.46 0 .77 285 .54 2 .63 7 9.79 18.17 47.47 54 .33 3.43 0.96 285 .73 2 .95 8 11.18 20.97 59.49 68.43 4.47 1 .15 285.92 3.22 9 12 .58 23 .77 72.62 83.26 5 .32 1 .29 286.06 3.41 10 13.98 26 .56 87.14 99 .18 6 .02 1.40 286.17 3.55 11 13.28 27 .26 101.02 114.40 6 .69 1.50 286.27 3.68 12 12 .58 25 .86 112.40 126.88 7 .24 1.58 286.35 3.78 13 11 .88 24.46 121.46 136.87 7.70 1.65. 286.42 3 .86 14 11.18 23 .07 128 .38 144.52 8.07 1 .70 286.47 3.92 15 10.48 21 .67 133.37 150.05 8 .34 1.74 286.51 3 .96 16 9.79 20 .27 136.62 153.64 8 .51 1.76 286 .53 3 .99 17 9 .09 18 .87 138 .29 155.49 8.60 1 .78 286.55 4.00 18 8 .39 17.47 138 .54 155.76 8 .61 1 .78 286.55 4 .00 19 7.69 16.08 137.50 154 .61 8.56 1 .77 286 .54 3 .99 20 6 .99 14 .68 135 .30 152 .18 8.44 1.76 286 .53 3.97 21 6.29 13.28 132 .04 148.58 8 .27 1 .73 286 .50 3.95 22 5 .59 11 .88 127.84 143.92 8.04 1 .70 286.47 3 .91 23 4 .89 10.48 122 .77 138.32 7 .77 1.66 286.43 3 .87 24 4.19 9 .09 116 .93 131.86 7.46 1 .62 286 .39 3 .81 25 3.49 7.69 110.34 124.62 7.14 1 .57 286.34 3.76 26 2.80 6 .29 103 .05 116.63 6 .79 1 .52 286 .29 3 .70 27 2.10 4 .89 95.13 107.94 6 .41 1 .46 286 .23 3.63 28 1 .40 3.49 86 .64 98.63 6 .00 1.40 286 .17 3 .55 29 0.70 2 .10 77.61 88.73 5.56 1 .33 286 .10 3.46 30 0 .00 0 .70 68 .11 78 .31 5 .10 1.25 286.02 3 .36 ,..,. "O c 0 ~ 25.00 20.00 :. 15.00 l u. 0 :0 ;:, ~ 10.00 ~ ~ 0 5.00 0.00 Inflow/Outflow Simulation 25-Year Storm Event , , , , 0 5 Pre----- Developme nt Hydrograph , ' , ' . ' 10 ' ' ' ' 15 20 Time (Minutes) Post-Post - Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 25 -....... 30 Post- Developme nt 'Free- Flow' Inflow I Outflow Simulation 50-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (Ft/Sec) 0 0.00 0.00 0.00 0 .00 0.00 0.00 284.77 0 .00 1 1.58 1.58 1.11 1.58 0 .23 0.16 284 .93 1.20 2 3 .16 4.74 4.72 5.85 0.56 0.29 285 .06 1.61 3 4.74 7.90 10.79 12.62 0.92 0.40 285 .17 1.90 4 6.32 11.06 19 .05 21.85 1.40 0 .53 285.30 2 .18 5 7.90 14.22 29.28 33.27 2.00 0.67 285.44 2.46 6 9.48 17.38 40.93 46.67 2.87 0.86 285.63 2.77 7 11.06 20.54 53.55 61.47 3.96 1.06 285.83 3 .09 8 12.64 23.70 67 .15 77 .26 5.05 1.25 286.02 3.35 9 14.22 26 .86 82.43 94 .01 5.79 1.37 286.14 3.51 10 15.80 30.03 99.25 112.46 6.60 1.49 286 .26 3.66 11 15.01 30.82 115.30 130.06 7.38 1.60 286.37 3.80 12 14.22 29.24 128.39 144.53 8.07 1.70 286.47 3 .92 13 13.43 27.66 138.79 156.04 8.63 1.78 286.55 4.00 14 12.64 26.07 146.76 164.86 9.05 1.84 286.61 4.07 15 11.85 24.49 152.54 171 .26 9.36 1.88 286.65 4.11 16 11.06 22.91 156.34 175.46 9.56 1.91 286.68 4.14 17 10.27 21.33 158.34 177.67 9 .67 1.92 286.69 4.16 18 9.48 19.75 158.72 178.09 9.69 1.92 286.69 4.16 19 8.69 18.17 157.64 176.89 9.63 1.92 286 .69 4.15 20 7.90 16.59 155.23 174.23 9 .50 1.90 286.67 4 .13 21 7 .11 15.01 151.62 170.24 9 .31 1.87 286 .64 4.11 22 6 .32 13.43 146.94 165.05 9 .06 1.84 286.61 4.07 23 5.53 11 .85 141.27 158.79 8 .76 1.80 286.57 4.02 24 4.74 10.27 134.72 151.54 8.41 1.75 286.52 3 .97 25 3.95 8 .69 127.37 143.41 8.02 1.70 286 .47 3 .91 26 3 .16 7 .11 119.31 134.49 7.59 1.64 286.41 3 .84 27 2.37 5.53 110.53 124.84 7 .15 1.57 286 .34 3 .76 28 1.58 3.95 101 .10 114.49 6.69 1.50 286.27 3.68 29 0.79 2.37 91 .05 103.47 6.21 1.43 286.20 3.59 30 0 .00 0.79 80.45 91.84 5.70 1.35 286.12 3.49 -"O c 0 ~ 25.00 20.00 G> 15.00 0.. l u.. 0 :a :J ~ 10.00 3'; 0 !§ 0 0.00 Inflow /Outflow Simulat ion 50 -Year Storm Even t I I I 0 5 Pre ----- Developme nt Hydrograph I ' I ' I ' I '\. 10 .... ' ' 15 ' 20 Ti me (Minutes ) Post-Post - Developme Developme nt Outflow nt Outflow Hydrograph With Without Detention Detention 25 ...... -- 30 Post- Developme nt 'Free- Flow ' Inflow I Ou tfl ow Si m ulation 100-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation Velocity (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) (FVSec) 0 0.00 0.00 0.00 0.00 0.00 0.00 284.77 0.00 1 1.65 1.65 1.16 1.65 0 .24 0.17 284 .94 1.22 2 3 .30 4.95 4.95 6.11 0 .58 0 .29 285 .06 1 .63 3 4 .95 8.25 11.31 13 .20 0.95 0.41 285 .18 1.92 4 6 .60 11.55 19.95 22 .86 1 .45 0 .54 285.31 2.2 1 5 8 .25 14.85 30.65 34.80 2 .07 0 .69 285.46 2.49 6 9 .90 18.15 42 .75 48 .80 3 .03 0 .89 285 .66 2.82 7 11.55 21.45 55 .88 64 .20 4 .16 1.10 285.87 3.14 8 13.20 24.75 70 .22 80 .63 5 .20 1.27 286 .04 3.38 9 14.85 28 .05 86 .31 98 .27 5.98 1.39 286 .16 3.54 10 16 .50 31.35 103.99 117.66 6.83 1 .52 286.29 3.70 11 15 .67 32 .17 120 .83 136.17 7 .67 1 .65 286 .42 3.85 12 14.85 30.52 134.55 151.35 8.40 1.75 286.52 3.97 13 14.02 28.87 145.46 163.42 8.98 1.83 286.60 4 .06 14 13.20 27.22 153 .83 172 .68 9.43 1 .89 286.66 4 .12 15 12.37 25.57 159 .91 179.41 9.75 1.93 28 6.70 4.17 16 11.55 23.92 163.91 183.83 9 .96 1.96 286.73 4.20 17 10.72 22.27 166 .03 186.18 10.08 1.97 286.74 4.22 18 9 .90 20.62 166.46 186.66 10.10 1.98 286.75 4.22 19 9.07 18.97 165.36 185.43 10.04 1.97 286.74 4 .21 20 8 .25 17.32 162.87 182.68 9.91 1 .95 286.72 4 .19 21 7.42 15.67 159.13 178 .54 9 .71 1.93 286 .70 4.16 22 6 .60 14.02 154.25 173.15 9.45 1.89 286.66 4.13 23 5.77 12.37 148.36 166.63 9.14 1.85 286 .62 4.08 24 4 .95 10.72 141 .54 159 .08 8.77 1 .80 286 .57 4.03 25 4 .12 9.07 133.88 150.61 8.37 1.74 286.51 3.96 26 3.30 7.42 125.47 141.31 7.92 1 .68 286.45 3.89 27 2.47 5 .77 116.37 131.24 7.43 1.61 286 .38 3 .81 28 1.65 4.12 106.58 120.50 6.96 1.54 286.31 3.73 29 0.82 2.47 96.15 109.06 6.46 1.47 286 .24 3.63 30 0 .00 0 .82 85.13 96 .97 5.92 1 .39 286.16 3.53 Inflow/Outflow Simulation 100-Year Storm Event 30.00 25.00 ' I .... ' I ' -I 'O ' c I ' 0 ,. .... ~ 20.00 Cl) .. CD Q. Q; CD 15.00 u.. 0 :0 :::J ~ ~ 10.00 0 !§ 0 5.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre -----Post-Post -.. -..... Post- Developme Developme Developme Developme nt nt Outflow nt Outflow nt 'Free- Hydrograph Hydrograph With Flow' Without Detention Detention Inflow /Outflow Simulation 2-Year Storm Even t 10 .00 9 .00 8.00 ....... "O 7.00 c 0 ~ Cl) 6.00 .... G> Q.. l 5.00 LI. 0 :0 j () 4.00 ....., ~ 0 ~ 3.00 0 2.00 l.00 0.00 0 5 10 15 20 25 30 Ti me (Minutes ) ---Pre-Development Hydrograph ---Total Post-Development Hydrograph Inflow/Outflow Simulation 5-Year Storm Event 14.00 12.00 -10.00 "O c 0 g Cl) ... Cl> 8 .00 Q. l ..... 0 :0 6.00 ::::J g ~ 0 !§ 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) ---Pre-Development Hydrograph ----Total Post-Development Hydrograph Inflow/Outflow Simulation 10-Year Storm Event 14.00 ----.-----,-----.-----.-----..,-----.., 12.00 ..P----+-----l-#+--4----+---'~-+------1-------l ~ 10.00 c 0 ~ Cl) ... CD 8.00 0... l u.. 0 :0 j 6.00 ~ ~ !§ 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre-Development Hydrograph ----Total Post-Development Hydrograph Inflow/Outflow Simulation 25-Year Storm Event 16 .00 14.00 12.00 -"O c 0 ~ 10.00 ... G> a.. 1 8.00 ~ 0 :a :J 0 -3'; 6 .00 0 !§ 0 4.00 2.00 0.00 0 5 10 15 20 25 30 Time (Minutes) Pre-Development Hydrograph ---Total Post-Development Hydrograph Inflow/Outflow Simulation 50-Year Storm Event 14 .00 -,, c 0 12 .00 0 G> Cl) ... G> a.. 10 .00 1 u.. 0 :0 8 .00 ::;, (.) -~ 0 6 .00 =§ 0 4.00 0 5 10 15 20 25 30 Ti me (Minutes) ---Pre-Development Hydrograph ---Total Post-Development Hydrograph Inflow /Outflow Simulation 100-Year Storm Event 20 .00 18 .00 16.00 -'O 14 .00 c 0 0 ~ 12 .00 ... Q) 0.. l 10 .00 "" 0 :0 :;:, ~ 8 .00 ~ 0 !§ 6.00 0 4 .00 2.00 0.00 0 5 10 15 20 25 30 Ti me (Minutes) Pre-Development Hydrograph ---Total Post-Development Hydrograph ~ ~·· vi..:: ~ ~~ li)\f;-1 ~~ ~~ ~tW>}-1 (-..o~~) -L~ t\)~: 2--~ . ~.~ ~~ ~+ tjo-2 ()\--~ uJ[:,-2. (iw2«.ct-_~f) ~~bvv ~·~w~~fd-~~8-'fq ~ ~ 't\wt '40 -\ ~ oo9._ ~ ~ i °'t~ @,bl-A otm -® &&:\ ~~ ~ Q~i fi:~Q: ~ ·@fukt~wbr~? ~s &xtdJ cz&t 6'J.t ~14 Mz-{i(_J~ dJlv w/':>.~ 2 Oh lW<~ smtoc '~ ~ Wlitc Jj)J'no.., ~ g/tCW: C\L f'X, ~Co ? ' ~sl.J clo-3 -fv~ ~ ~cX(3~!f'1 ~=,a ~~-4 ~ )1~ '~~.5' ~~-~? ~?~? ~~~? . . ,. .. .. _ . . - • E i'l G l i'l EE R l i'l G CONSULTING ENGINEERING & LAND SURVEYING 4444 CARTER CREEK PKWY, SUITE 108 BRYAN, TEXAS 77802 14091846-268814091 846-3094 Hank Smith, P.E. Plans and Specifications Review Team Watershed Management Division, TNRCC 1700 North Congress, Rm. 1117-A Austin, TX 78711 October 11, 1994 RE: The Replat of Tract "B", Block 55, Southwood Valley, Section 24A College Station, Brazos County, Texas Dear Mr. Smith: • Transmitted herewith are plans for the above referenced replat. Please accept these plans for re yiew agd , co Rside q ltion. The ~w in~ude a set of ~lue.llte'j rints, an 3 engineer's report, and stan dird specifications. yo h M fJl@J/tlA[J~ al ) lCZSii , #ease do not hesitate to do so at the address, phone number, or fax J umber stated on this letterhead. All inquiries should be addressed either to myself or E M'l Havel. Thank you for your time. · Sincerely, ~~ Don Garrett, P.E., R.P.L.S. Garrett Engineering Engineering Report For Sanitary Sewer Improvements To A Replat Of Tract "B" Block 55 ' Southwood Valley -Section 24A College Station, Brazos County, Texas Prep a red By : GARRETT ENGINEERING CONSUL TING ENGINEERING & LAND SURVEVIHG 4444 CARTER CREEK PARKWAY, SUITE 10I . BRYAN , TEXAS 77102. (409) 14'-2£81 • (409) 841 -3094 * October, 1994 * ENGINEERING REPORT to accompany REPLAT OF TRACT "B", BLOCK 55 SOUTHWOOD VALLEY, SECTION 24A COLLEGE STATION, BRAZOS COUNTY, TEXAS The project is situated adjacent to Welsh Ave., and south of San Mario Ct. in Southwood Valley, College Station, Brazos County, Texas. Tract "B", Block 55 of Southwood Valley -Section 24A consists of 15 lots, these 15 lots being established within the bounds of a 3.93 acre tract Additionally, the project is surrounded by developed property. Therefore no future expansion of proposed facilities will be necessary. Soils within the area have shown historically to be quite stable. No faults exist within the project area, and no stability problems are foreseen, other than those caused by the expansive clays typical of Brazos County. Sanitary sewer needs are met by a 6" diameter SDR 26-3034 PVC pipe graded at 0.6% throughout its entire length. The pipe loading was calculated to be 0.0288 cfs. 1his loading is calculated by taking 15 lots, each lot housing 4 residents, each resident producing 100 gpd. The daily loading is factored by 3 to get peak hourly loading, and an additional 10% of daily loading is added to the peak to account for infiltration. Daily Loading = 15 lots * 4 residents/ lot * 100 gpd I resident = 6000 gpd Peak Loading= Daily Loading* 3 = 6000 gpd * 3 = 18000 gpd Infiltration= Daily Loading* 0.10 =6000 gpd * 0.10 = 600 gpd Total Loading = Peak Loading + Infiltration = 18000 gpd + 600 gpd =18,600 gpd Flow in Cubic Feet per Second = Flow in Gallons per Day * A * B Where: A = 0.13368 Cubic Feet per Gallon B = 0.00001157 Days per Sec Flow in Cubic Feet per Second= 18,600 gpd * 0.13368 * 0.00001157 = 0.0288 Cubic Feet I Sec According to Manning Pipe theory, a 6" line graded at 0.6% can carry 0.436 cfs. Where: Q = flow in Cubic feet per second, n = manning's roughness coefficient, n = 0 .013 for PVC pipe A = Area of pipe in square feet A= ml2/4 A= 1t*(0.5)2/4 A=0.19635 R =Hydraulic Radius R=A/P Where A = Area of pipe in square feet P = Wetted Perimeter p =1td p = 1t*0.5 p = 1.570796 R = 0.1963511.570796 R = 0.125 S 0 = Slope of Pipe S0 = 0.006 Q = (1.49 I 0.013) * 0.19635 * 0.125213 * 0.0060.s Q =0.436 CFS Since the ratio of loading to capacity is 0.0288/0.436 = 0.066, the resulting velocity (from design tables) will be 0.55 of full flow velocity. Full flow velocity is calculated as follows: Where: V full = full flow velocity Q = full flow capacity in cfs Q = 0.436 cfs A = Area of Pipe in square feet A= 0.19635 ft2 v full= 0.436/0.19635 V full = 2.22 ft I sec The resulting velocity for a pipe flowing at 0.066 full, being 0.55 of full flow velocity, is thus V 0.066 full = 0.55 * 2.22 ft I sec Vo .066 full= 1.22 ft/sec. The 6" diameter pipe flows into an 8" diameter main line which in turn flows into a 12" diameter line. Both the 8" and 12" lines were designed to accommodate loading from a 6" line as evidenced by the prior existence of a 6" diameter sanitary sewer stub-out. In addition, manhole spacing within this project is required to be 500 feet or less. Four additional manholes are proposed for this project. The distance from the existing manhole that will be branched to the first manhole (#4 on plans) is 40 feet The distance to the next manhole (#3 on plans) is 105 feet. The distance to the next manhole (#2 on plans) is 105 feet, and the next manhole (#1 on plans) is 200 feet away. Therefore, a maximum spacing of 200 feet has been provided. • \ ~ I /~-~""------------_c \ ~ ----U) I ', __ / ---------w I S ~ ~--·-·-·-·-·-_'\2j +-® ~ CAMERA LOCATION AND DIRECTION MAP (NOT TO SCALE) Standard Specifications For Sanitary Sewer Improvements To A Replat Of Tract "B", Block 55 Southwood Valley -Section 24A College Station, Brazos, County, Texas Prepared For: Thomas Properties P.O. Box 10106 College Station, Texas 77840 Telephone: (409) 764-0704 Prepared By: GARRETT ENGINEERING CONSUL TING ENGINEERING & LAND SURVEVING 4444 CARTER CREEK PARKWAY, SUITE 1DI -BRYAN, TEXAS 77102 -(409) 14'-2181 -(409) 84'-3094 * October, 1994 * REPLAT OF TRACT "B", BLOCK 55 SOUTHWOOD VALLEY -SECTION 24A SANITARY SEWER IMPROVEMENTS COLLEGE STATION, BRAZOS COUNTY, TEXAS SPECIAL PROVISIONS These special provisions are provided to enhance and clarify the following standard construction specifications. It shall be the responsibility of the Contractor to thoroughly familiarize himself with these specifications as well as all referenced and applicable standard specifications from the Texas Natural Resources Conservation Commission (TNRCC), American Society for Testing Materials (ASTM), American Water Works Association (A WW A), and the Occupational Safety and Health Association (OSHA). 1. For all open cut construction, the width of the trench shall be minimized, but shall be wide enough to allow proper pipe installation and trench backfill and compaction as required by these specifications. Ledge rock, boulders, and large stones shall be removed to provide a minimum clearance of 4 inches in all directions of the pipe being installed. Bedding classes I, II, or III as described in ASTM D-2321 (ANSI K65.171) shall be used for this project provided the proper strength pipe is used with the specified bedding to support the anticipated load. Backfill shall be of suitable material removed from excavation except where other material is specified. Debris, large clods or stones, organic matter, or other unstable material shall not be used for backfill within two feet of the top of the pipe. Backfill shall be placed in such a manner as not to disturb the placement of the pipe. 2 . Deflection tests shall be required for all pipelines installed in this project. The tests shall be conducted after the final backfill has been in place no less than 30 days . The test shall be conducted using a rigid mandrel as described in the specifications, with a diameter equal to 95% of the inside diameter of the pipe being tested. The pipeline will be considered defective and will fail this test if the mandrel cannot be had pulled through the entire length of new pipe. 3 . When new sanitary sewers are installed, they shall be no closer than 9 feet to any existing waterline (sanitary sewers running parallel to waterlines shall be installed in separate trenches). Where the 9 foot interval cannot be achieved, the following guidelines shall apply: A. New sanitary sewer parallels a waterline: The sewer line shall be constructed of cast iron , ductile iron, or PVC meeting ASTM specifications with a pressure rating for both the pipe and joints of 150 psi. The sewer shall be located a minimum of 2 feet below the waterline and a minimum 4 foot horizontal separation shall be maintained (all distances shall be OD to OD). B . New sanitary sewer crossin2 under a waterline: The sewer line shall be con structed of cast iron, ductile iron, or PVC meeting ASTM specifications with a pressure rating for both the pipe and joints of 150 psi. C . New sanitary sewer crossin2 over a waterline: The sewer line shall be constructed of cast iron, ductile iron, or PVC meeting ASTM specifications with a pressure rating for both the pipe and joints of 150 psi. An alternate for construction would be to encase the sewer line in a minimum 18 foot length of 150 psi pressure class pipe that is two nominal sizes larger than the new sewer line. The sewer line shall be supported at 5 foot intervals or the annular space shall be filled to the springline with washed sand. The encasement pipe shall be centered on the waterline, and both ends shall be sealed with cement grout or a manufactured seal. Work to be performed under Part S.l includes materials, labor and superintendence required to install a complete sanitary sewer main, including manholes, appurtenances and any other componen°ts required to construct a complete system. PART S ."l SANITARY SEWER MAINS SPECIFICATION NO. S.101 GENERAL PROVISIONS S.101.1 DESCRIPTION Work to be performed under Part S.l included materials, labor and superintendence required to install a complete sewer line, including manholes, appurtenances and any other components required to construct a complete system. S.101.2 RELATED WORK SPECIFIED ELSEWHERE A. Definition of Terms B. General Conditions C. Parts WS.l -WS.5 S.103.3 QUALITY ASSURANCE All work that may be called for in the specifications but not shown on the drawings, or all work that may be shown on the drawings but not called for in the specifications, shall be performed by the Contractor as if described in both. Should work be required which is not set forth in either document, but which work is nevertheless required for the fulfilling of the intent thereof, then the Contractor shall perform all such work as fully as if it were specifically set forth in the Contract. S.104.4 SUBMITTALS A. Shop Drawings Refer to Part 9 of General Conditions. B. Manufacturer's Certificate of Compliance Contractor shall submit manufacturer's Certificate of Compliance stating that the materials furnished and installed have complied with these specifications and material specifications referenced herein. S.101.5 PRODUCT DELIVERY, STORAGE AND HANDLING A. Refer to Specifica tion No. WS.101.0 Materials. S.101/1 B. All pipe delivered to the jobsite shall have the appropriate AWWA or ASTM designation, and/or SDR designation clearly stamped on the outside of all joints of pipe at the factory. Any pipe without the appropriate designations will be rejected. S.101.6 INSTALLATION Install all materials to line and grade, as indicated on the plans, and furnish cut-sheets to the City Engineer. S.101.7 FIELD QUALITY CONTROL A. Perform leakage tests of the piping system (including manholes) as specified. B. Perform deflection tests on all PVC sewer piping, as specified in Specification No. S.104. END OF SPECIFICATION S .101/2 SPECIFICATION NO. S.102 LEAKAGE TESTS S.102.1 DESCRIPTION This section specifies leakage tests of sanitary sewer collection lines. In general, leakage tests of sanitary sewers shall be by exfiltration or by air test. Test sewer lines after backfilling but before placement of pavement (if applicable). S.102.2 LEAKAGE ALLOWANCE A. Exfiltration Test The maximum allowable leakage for sanitary sewers, unless otherwise stated, is 200 gallons per inch of nominal diameter per mile of sewer line per 24 hours. B. Air Test (Alternative to Exfiltration) 1. For VCP (Per ASTM C828) The leakage allowance requirements of the air test shall be considered satisfied if the time required for the pressure to decrease from 3.5 ·pounds per square inch (psi) to 2.5 psi is not less than that shown in Table 1. TABLE 1 Minimum Test Time For Various Vitrified Clay Pipe Sizes Nominal Pipe Size in. 3 4 6 8 10 12 15 18 T(time) min/100 ft. 0.2 0.3 0.7 1. 2 1.5 1.8 2. 1 2.4 S.102/1 Nominal T(time) Pipe Size in. min/100 ft. 21 3.0 24 3.6 27 4.2 30 4.8 33 5.4 36 6.0 39 6.6 42 7.3 2. For PVC and Ductile Iron Pipe The leakage allowance requirements of the air test shall be considered satisfied if the time required for the pressure to decrease from 3.5 psi to 3.0 psi is not less than that shown in Table 2. TABLE 2 Minimum Test Time For Various Sizes Nominal Pipe Size in. 6 8 10 12 T(time) min/100 ft. 4.0 5.0 6.5 7.5 C. Failure to Meet Test Requirements S.102.3 Should any section of sewer line fail to pass these standards, locate the defect by visual inspection or by television inspection and repair the· damage. After the defects have been corrected, retest the sewer line as previously specified. MATERIALS BY CONTRACTOR Furnish all necessary apparatus, including gauges and meters. Water required shall be furnished by the Contractor and purchased from the City. A. Exfiltration Test 1. Measuring devices necessary to measure the drop in water level in a manhole. 2. A sufficient quantity of water. 3. Plugs. S.102/2 B. Air Testing 1. Air Hose. 2. Air control equipment consisting of pressure gauge and valve. 3. An air compressor. 4. Plugs. S.102.4 PREPARATION A. Make sure all necessary materials and supplies are on hand before beginning exfiltration tests. B. Do not begin testing until directed by the City Engineer, or until the City's representative is present. C. Air Testing 1. Groundwater will be measured where it is known to exist and a correction made to the allowable time as set out in Tables 1 and 2. 2. At the time the sewer line is installed, the Contractor shall install a 1-1/2" diameter standpipe from the top of the sewer line to a point at or above ground level to be used to measure the groundwater. The bottom of the standpipe shall be perforated for one (l') foot and enclosed with loose gravel to allow the groundwater to seek its natural level within the standpipe. The top of the standpipe shall be capped to prevent foreign matter from entering. Generally a 1-1/2" monitor standpipe shall be installed in each run of pipeline between manholes. 3. Innnediately prior to the line acceptance test, the groundwater shall be determined by removing the cap and measuring the height in feet of water over the invert of the sewer line. This height in feet shall be multiplied by 0.43 to establish the pounds of pressure that will be added to all readings. For example, if the height of water is 11-1/2 feet, then the added pressure will be 5 psig. This increases the 3.5 psig to 7.5 psig. The allowable drop and timing remain the same. S .102/3 S.102.5 TEST PROCEDURE A. Exf iltration 1. Isol ate the section of sewer line to be tested 'with plugs on either end. Place the downstream plug at the inlet of the downstream manhole. Place the upstream plug at the inlet of the upstream manhole. The downstream plugs shall be provided with a two (2") inch vent pipe extending upward six (6 ') feet . 2 . Fill the sewer line with water using the upper manhole unti l all air is forced out through the downstream vent tube. Measure the drop in the water level in the manhole over a specific time and calculate the loss of water due to exfiltration. B. Air Testing 1. The section of the pipe to be tested is plugged at each end. The ends of all branches, laterals and wyes which are to be included in the test are sealed or plugged. All plugs shall be carefully braced to prevent slippage and blowout due to internal pressure. One of the plugs provided must have an inlet tap or other provision for connecting an air hose. 2. Connect one end of the air hose to the inlet tap on the plug and connect the other end of the hose to a portable air control equipment. The air control equipment shall consist of pressure gauges and valves used 'to control the rate at which the air flows to the test section and to monitor the a ir pressure inside the pipe. Air control equipment can then be connected to a source of air supply such as a portable air compresso r. 3 . After the air hoses are properly connected, inject air into the test section. Monitor the air pressure in pounds per square inch gauge (psig). 4. When the pressure inside the test section reaches 4.0 psig, throttle the air supply so that the internal pressure is maintained between 4.0 and 3.5 psig, for at least two (2) minutes. These two minutes allow time for the temperature of the air to come to equilibrium with the pipe walls . S.10 2 /4 5. After the temperature has been allowed to stabilize for the two minute period, the air supply should be disconnected and the pressure allowed to decrease to 3.5.psig. At 3.5 psig a stopwatch is to be started to determine the time required for the pressure to drop. 6. The section of pipeline being tested shall be considered acceptable if the time required for the pressure to decrease from 3.5 psig is equal to or greater than that shown in Tables 1 or 2. S.102.6 MEASUREMENT AND PAYMENT A. Measurement Testing of sewer line will not be measured. B. Payment This item will not be a separate bid item. Cost for work herein specified, including the furnishing of all materials, equipment, tools, labor and incfdentals necessary to complete the work, shall be included in the unit price bid for sewer lines in pla~e. However, the unit price bid for sewer lines in place but not tested will be reduced by two (2%) percent on partial payments. END OF SPECIFICATION S.102/5 SPECIFICATION NO. S.103 DUCTILE IRON PIPE AND FITTINGS S.103.l DESCRIPTION This section describes the manufacture, construction and installation of ductile iron pipe (DIP) and fittings. S.103.2 RELATED WORK SPECIFIED ELSEWHERE A. Part WS.3 -Excavating, Trenching and Backfilling B. Specification No. S.102 -Leakage Tests C. Specification No. S.201 -Manholes S.103.3 APPLICABLE STANDARDS A. AWWA -Cl04, Cl05, Cl10, Clll, Cl15, Cl50, Cl51 and C600 B. ASTM -C33 and Cl50 S.103.4 SUBMITTALS A. Submit manufacturer's dat~ on pipe furnished, indicating compliance with the specifications regarding dimensions, thickness, wei ghts and materials. B. Submit manufacturer's "Certificate of Compliance," stating that the materials furnished comply with this specification. S.103.5 MATERIALS A. Pipe 1 . Ductile iron gravity and pressure pipe four (4") inches in diameter and larger shall conform to the current AWWA Cl51 (ANSI A21.51) standard. Ductile iron pipe shall be approved by the Underwriter's Laboratory, and shall be accepted by the State Fire Insurance Board for use in water distribution systems without penalty. All pipe shall be new, and shall have the AWWA designation, thickness class and size of pipe stamped on the outside of each joint. Ductile iron pipe less than six (6") inches in diameter will not be allowed. S.103/1 2. Ductile iron thickness shall conform in all respects to the current AWWA Cl50 standard, based on a minimum of 200 psi working pressure, embedment Class C with twenty (20') feet of cover. Pipe four (4") inches through twenty-four (24") inches shall be thickness Class 52, unless otherwise specified on the plans. For larger diameters or deeper cover, special design will be provided. 3. Flanged pipe shall conform to AWWA Cll5, and be minimum Class 53. B. Joints 1. All ductile iron pressure pipe shall be furnished with one of the following types of joints, and as described in the proposal or shown on the p l ans. Type Jo i nt Push-on Joint Mechanical Joint Flanged Ends Standard AWWA Clll AWWA Clll AWWA Cll5 2. All screwed flanges shall be ductile iron. C. Fittings 1. Fittings for ductile fron pipe shall be of cast iron or ductile iron, and shall con f orm to AWWA CllO, unless otherwise specified in the Proposal, special specifications or on the plans. 2. Fitting joints shall be push-on, mechanical, flanged or special internally locked joint, with body thickness and radii of curvature conforming to AWWA CllO. D. Coating and Lining All pipe and fittings shall be bituminous coated outside and inside, all in accordance with AWWA Cl04. E. Bolts and Nuts Bolts and nuts for mechanical joints shall be of a high strength corrosion resis t ant low alloy steel, and conform to AWWA Clll. Flange bolts and nuts for above ground installation shall conform to Appendix A o f AWWA Cll5. Flange bolts and nuts for below ground installation shall be Type 304 or 316 stainless steel. S.103/2 F. Flange Gaskets Flange gaskets shall be full faced, and conform to Appendix A of AWWA CllS. G. Polyethylene Encasement Polyethylene encasement shall conform to AWWA ClOS. Joint tape shall be self-sticking PVC or polyethylene, 10 mils thick. H. Concrete for Blocking or Encasement Cement shall meet ASTM ClSO, Type I. Aggregates shall meet ASTM C33. The twenty-eight (28) day compressive strength shall be 2,000 psi, or more. S.103.6 INSPECTION, STORAGE AND HANDLING A. Refer to Specification No. WS.101.0 paragraph C and D for general requirements. B. Pipe shall not be stacked higher than the limits shown in Table 1. The bottom tier shall be kept off the ground on timbers, rails or concrete. Pipe in tiers shall be alternated: bell, plain end; bell, plain end. At least two (2) rows of 4" x 4" timbers shall be placed between tiers and chocks affixed to each end in order to pre~ent movement. Pipe Size (in.) 4 6 8 10 12 14 16 18 20 24 30 36 42 48 54 TABLE 1 Maximum Stacking Heights Ductile Cast-Iron Pipe* * For 18 or 20 ft. len g ths . s . 103/3 Number of Tiers 16 13 11 10 9 8 7 6 6 5 4 4 3 3 3 C. Gaskets for mechanical and push-on joints to be stored shall be placed in a cool location out of direct sunlight. Gaskets shall not come in contact with petroleum products. Gaskets shall be used on a first-in, first-out basis. D. Mechanical joint bolts shall be handled and stored in such a manner that will ensure propoer use with respect to types and sizes. S.103.7 CONSTRUCTION METHODS A. Trench Width B. Trench widths shall not exceed those shown in Table 2. TABLE 2 Suggested Trench Widths At the Top of the Pipe* Nominal Pipe Size (In.) 4 6 8 10 12 14 16 18 20 24 30 36 42 48 54 Trench Max. 28 30 32 34 36 38 40 42 44 48 54 60 66 72 78 * The trench should never be wider than the width used as design criterion. Pipe Installation Width (In.) Min. 20 22 24 26 28 30 32 34 36 40 46 52 58 64 70 1. All pipe fittings, services and other appurtenances shall be examined carefully for damage and other defects immediately before installation. Defective materials shall be marked and held for inspection by the Engineer, who may prescribe corrective repairs or reject the material. S.103/4 2. All lumps, blisters, and excess coating shall b e removed from the socket and plain end and the inside of the bell shall be wiped clean and dry and be free from dirt, sand, grit or any foreign material before the pipe is laid. 3. Foreign material shall be prevented from entering the pipe while it is being placed in the trench. During laying operations, no debris, tools, clothing or other materials shall be placed in the pipe. 4. As each length of pipe is placed in the trench, the joint shall be assembled and the pipe brought to correct line and grade. The pipe shall be secured in place with approved backfill material. 5. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a watert~ght plug, or other means approved by the Engineer. When practical, the plug shall remain in place until the trench is pumped completely dry. Care must be taken to prevent pipe flotation, should the trench fill with water. C. Joint Assembly 1. Push-on joints shall be assembled as follows: a. Thoroughly clean the groove and bell socket and insert the gasket, making sure that it faces the proper direction and that it is correctly seated. b. After cleaning dirt or foreign material from the plain end, apply lubricant in accordance with the pipe manufacturer's recommendations. The lubricant is supplied in sterile cans, and every effort should be made to keep it sterile. c. Be sure that the plain end is beveled; square or sharp edges may damage or dislodge the gasket and cause a leak. When pipe is cut in the field, bevel the plain end with a heavy file or grinder to remove all sharp edges. Paint bare surfaces with proper coating. Push the plain end into the bell of the pipe. Keep the joint straight while pushing. Make deflection after the joint is assembled. d. Small pipe can be pushed into the bell socket with a long bar. Large pipe require additional power, such as a jack, lever puller or backhoe . A timber header should be used between the pipe and jack or backho e bucket to avoid damage to the pipe. S.103/5 2. Mechanical joints shall be assembled as follows : a. Wipe clean the socket and plain end. The plain end, socket and gasket should be washed with a soap solution to improve gasket seating. b. Place the gland on the plain end, with the lip extension toward the plain end, followed by the gasket, with the narrow edge of the gasket toward the plain end of the pipe. c. Insert the pipe into the socket and press the gasket firmly and evenly into the gasket recess. Keep the Joint straight during assembly. Make deflection after joint assembly, but before tightening the bolts. d. Push the gland toward the bell, and center it around the pipe with the gland lip against the gasket. e. Align bolt holes and insert bolts, with bolt heads behind the bell flange, and tighten opposite nuts to keep the gland square with the socket. f. Tighten the nuts in accordance with Table 3. TABLE 3 Mechanical Joint. -Bolt Torques Bolt Diameter (in.) 5/8 3/4 1 1-1/4 Torque (ft.-lb.) 45-60 75-90 85-100 105-120 3. When it is necessary to deflect pipe from a straight line in either the vertical or horizontal plane, or where long radius curves are permitted, the amount of deflection shall not exceed that shown in Tables 4 or 5. S.103/6 ,...... 0 w --...J Pipe Diameter in. 4 6 8 10 12 14 16 18 20 24 30 36 42 48 54 Deflection Angle deg. 5 5 5 5 5 3 3 3 3 3 3 3 2 2 l~ TABLE 4 Maximum Deflection Full Length Pipe -Push-on Type Joint Approx. Radius of Curve Produced Maximum Deflection -in. by Succession of Joints -ft. (18 ft. length) (20 ft. length) (18 ft. length) (20 ft. length) 19 21 205 230 19 21 205 230 19 21 205 230 19 21 205 230 19 21 205 230 11 12 340 380 11 12 340 380 11 12 340 380 11 12 340 380 11 12 340 380 11 12 340 380 11 12 340 380 7~ 8 510 570 7~ 8 510 570 5~ 6 680 76 0 Ul ....... 0 w -CX> Size of Pipe in. 4 6 8 10 12 14 16 18 20 24 30 36 42 48 Deflection Angle deg.-min. 8-18 7-7 5-21 5-21 5-21 3-35 3-35 3-0 3-0 2-23 2-23 2-5 2-0 2-0 TABLE 5 Maximum Deflection Full Length Pipe -Mechanical-Joint Pipe Approx. Radius of Curve Produced Maximum Deflection -in. by Succession of Joints -ft. (18 ft. length) (20 ft. length) (18 ft. length) (20 ft, length) 31 35 125 140 27 30 145 160 20 22 195 220 20 22 195 220 20 22 195 220 13~ 15 285 320 13~ 15 285 320 11 12 340 380 11 12 340 380 9 10 450 500 9 10 450 500 8 9 500 550 7~ 8 510 570 7~ 8 510 570 4. Pipe Cutting a. Cutting pipe for the insertion of valve~, fittings or closure pieces shall be done in a neat, workmanlike manner, without creating damage to the pipe or cement-mortar lining. Seal coat bare surfaces and cut ends per manufacturer's reconunendations. b. Ductile cast iron may be cut using an abrasive pipe saw, rotary wheel cutter, guillotine pipe saw, milling wheel saw or oxyacetylene torch. Make each cut square to the centerline of the pipe. c. Cut ends and rough edges shall be ground smooth, and for push-on joint connections, the cut end shall be beveled. D. Polyethylene Tube Protection 1. General All cast-iron and ductile iron pipe and fittings shall be provided with polyethylene tube protection. Completely cover all fittings and connections with polyethylene film held securely in place with joint tape or strapping. The polyethylene .encasement shall prevent contact between the pipe and the surrounding backfill and bedding material. 2. Installation a. Pipe This specification includes three different methods for the installation of polyethylene encasement on pipe. Methods A and B are for use with polyethylene tubes, and Method C is for use with polyethylene sheets. b. Method A 1) Cut polyethylene tube to a length approximately two (2') feet longer than that of the pipe section~ Slip the tube around the pipe, centering it to provide a one (l') foot overlap on each adjacent pipe section, and bunching it accordion-fashion lengthwise until it clears the pipe ends. 2) Lower the pipe into the trench and make up the pipe joint with the preceding section of pipe. A shallow bell hole must be made at joints, to facilitate installation of the polyethylene tube. S.103/9 3) After assembling the pipe joint, make the overlap of the polyethylene tube. Pull the bunched polyethylene from the preceding length of pipe, slip it over the end of the new length of pipe, and ·secure in place. Then slip the end of the polyethylene . from the new pipe section over the end of the first wrap, until it overlaps the joint at the end of the preceding length of pipe. Secure the overlap in place. Take up the slack width to make a snug, but not tight, fit along the barrel of the pipe, securing the fold at quarter points. 4) Repair any rips, punctures or other damage to the polyethylene with adhesive tape or with a short length of polyethylene tube cut open, wrapped around the pipe, and secured in place. Proceed with installation of the next section of pipe in the same manner. c. Method B 1) Cut polyethylene tube to a length approximately one {l') foot shorter than that of the pipe section. Slip the tube around the pipe, centering it to provide six (6") inches of bare pipe at each end. Make polyethylene snug, but not tight; secure ends as described in Method A. 2) Before making up a joint, slip a three (3') foot length of polyethylene tube over the end of the preceding pipe section, bunching it accordion- fashion lengthwise. After completing the joint, pull the three (3') foot length of polyethylene over the joint, overlapping the polyethylene previously installed on each adjacent section of pipe by at least one (l') foot; make snug and secure each end as described in Method A. 3) Repair any rips, punctures or other damage to they polyethylene as described in Method A. Proceed with installation of the next section of pipe in the same manner. d. Method C 1 ) Cut polyethylene sheet to a length approximately two (2') feet longer than that of the pipe section. Center the cut length to provide a one (l') foot overlap on S.103/10 each adjacent pipe section, bunchin g it until it clears the pipe ends. Wrap the polyethylene a r ound the pipe, so that it circumferentially overlaps the top quadrant of the pipe. Secure the cut edge of polyethylene sheet at intervals of approximately three (3') feet. 2) Lower the wrapped pipe into the trench and make up the pipe joint with the preceding section of pipe. A shallow bell hole must be made at joints to facilitate installation of the polyethylene. After completing the joint, make the overlap as described in Method A. 3) Repair any rips, punctures or other damage to the polyethylene as described in Method A. Proceed with installation of the next section of pipe in the same manner. e. Pipe-Shaped Appurtenances Cover bends, reducers, offsets and other pipe-shaped appurtenances with polyethylene in the same manner as the pipe. f. Odd-Shaped Appurtenances When valves, tees·, crosses and other odd-shaped pieces cannot be wrapped practically in a tube, wrap with a flat sheet or split length of polyethylene tube b y passing the sheet under the appurtenance and bringing it up around the body. Make seams by bringing the edges together, folding over twice, and taping down. Handle width and overlaps at joints as described in Method A. Tape polyethylene securely in place at valve stem and other penetrations. g. Openings In Encasement Provide openings for branches, service taps, and similar appurtenances by making X-shaped cut in the polyethylene and temporarily folding back the f ilrn. After the appurtenance is installed, tape the slack securely to the appurtenance and repair the cut, as well as any other damaged areas in the polyethylene, with tape.· h. Junctions Between Wrapped and UnWrapped Pipe Where polyethylene-wrapped pipe joins an adjacent pipe that is not wrapped, extend the polyethylene wr ap to cover the adjacent pipe for a distance of at least two (2') feet. Secure the end with circumferential turns of tape. S.103/11 E. Embedment Install embedment as shown in Part S.3, or on the p l ans. F. Reaction anchorage and Blocking 1. Block, anchor or harness all piping subject to internal pressure to preclude separation of joints. Provide suitable reaction blocking, anchors, harnesses or other acceptable means for preventing movement of pipe caused by internal pressure for all unlugged bell and spigot or all-bell tees, Y-branches, bends deflecting 11-1/4 degrees or more, and plugs which are subject to internal pressure in excess o f 10 psi. 2. Extend 2,000 psi concrete blocking from the fitting to solid, undistrubed earth, and install so that all joints are accessible for repair. The bearing area shall be as shown on the plan. Provide enough concrete bearing area against the ditch to limit soil loading to 2,000 psf from the thrust produced at an internal pressure in the pipe of 200 psi. 3. If adequate support against ground cannot be obtained, install metal harness, anchorages consisting of steel rods across the joint and securely anchor co pipe and fitting, or install other adequate anchorage facilities to provide necessary support. Should the lack of a solid vertica l excavation face be due to improper trench excavation, the entire cost of furnishing and installing metal harness anchorages shall be borne by the Contractor. 4. Protect from corrosion all steel clamps, rods, bolts and other metal accessories used in reaction anchorages or joint harnesses subject to submergence, or in direct contact with earth and not encased in concrete, with two (2) coats of bituminous paint applied to clean, dry metal surfaces. G. Minimum Cover Minimum cover shall be as follows: 4" through 12", 42" cover; 15" through 36", 72" cover as measured below top of curb to the top o f pipe, or as otherwise directed by the Engineer. S.103.8 MEASUREMENT A. Pipe Pipe will be measured (by horizontal distance) from center o f manhole to center of manhole, cleanout or end of pipe, without d e duction f or the leng th of intermedia te fittin g s, services, ma nholes o r c l ean o uts. S .103/1 2 B. Fittings Fittings will not be considered a measured item. C. Concrete Thrust Blocking Concrete thrust blocking will not be considered a measured item. D. Excavation, Embedment Materials and Backfill Refer to Specification No. WS.309.0 paragraph A. E. Leakage Test Ref er to Specification No. s_ 102. 6. F. Manholes Refer to Specification No. s. 201. G. Cleanouts Refer to Specification No. S.202. H. Service Connections and Laterals Refer to Specification No. S.203. S.103.9 PAYMENT A. Pipe Payment will be made at the price bid per foot for furnishing and installing pipe, which bid price will include all costs for the complete pipe installation, including fittings, trenching and backfill, embedment, compaction or tamping, testing, final cleanup and all other work not otherwise provided for in the bid Proposal. B. Retainage for Incomplete Work for Partial Payments Pipeline in place, but not backfilled, compacted, tested, cleaned and/or right-of-way cleaned up, will not be considered 100% complete. The percent of pipe completed will be reduced b y the following percentages: 1. Incomplete backfill, compaction and cleanup -6%. 2. Incomplete leakage test -2%. S.103/13 3. Monthl y estimates will be paid b y the linear foot of equivalent pipe properly placed, backfilled, compacted, tested, cleaned and right-of-way cleaned up. END OF SPECIFICATION S .10 3 /1 4 SPECIFICATION NO. S.104 POLYVINYLCHLORIDE PIPE AND FITTINGS S.104.1 DESCRIPTION The work specified under this section includes the manufacture, construction and installation of polyvinylchloride (PVC) pipe and fittings for gravity and pressure sewer mains. S.104.2 RELATED WORK SPECIFIED ELSEWHERE A. WS.3 -Excavating, Trenching and Backfilling B. Specification No. S.102 -Leakage Tests C. Specification No. S.201 -Manholes D. Specification No. S.202 -Ductile Iron Pipe and Fittings S.104.3 APPLICABLE STANDARDS A. AWWA -Cl04, Cl05, CllO, Clll and C900 B. ASTM -C33, Cl50, Dl598, Dl78 4 , D2122, D2241, D256 4 , D2672, D3212, D3139 and F477 S. 104 ;4 SUBMITTALS A. Submit manufacturer's data on pipe furnished indicating complianc e with the specifications regarding dimensions, thickness, weights and materials. B. Submit manufacturer's "Certificate of Compliance" stating that th e materials furnished comply with this specification. C. Submit shop drawings for all products described in this section complete with all dimensions, clearances, wall thicknesses, dead and live load calculations for pipe with embedment classes shown as on the plans (Ws=l20pcf, S.F.=1.5). D. The manufacturer shall review plans and specifications to sat i sfy himself that his pipe will support the dead and live loads o f this project without damage to the pipe for the types of embedment called for on the plans. If the next higher class embedment is required, notify the Contractor and Engineer. The Contractor shall us e th e next higher embedment without extra cost to the City , i f th e n ex t higher embedment is required by pipe manufacturer. S .104/1 S.104.5 MATERIAL S A. PVC Gravity and Pressure Pipe 1. Polyvinylchloride (PVC) gravity and pressure pipe in sizes four (4") inch through twelve (12") inch, except as otherwise noted on the plans, shall conform to the ASTM 02241 standard, be UL listed and be approved by the National Sanitation Foundation. Pipe shall be made from NSF approved Class 12454-B PVC compound conforming to ASTM 01748. PVC pipe wall thickness shall be based on a working pressure rating of 125 psi at 73.4°F (SOR-32.5) and embedment Class B with a maximum of seventeen (17') feet of cover. The outside diameter shall be identical to steel pipe (Table 1, AWWA C900). All pipe shall be new and have the ASTM designation, SOR, pressure rating and size pipe stamped on the outside of each joint . (follow requirements of AWWA C900 Section 2.5.2. Markings). PVC pipe less than six (6") inches in diameter will not be allowed. All physical and chemical test should be conducted at 73°F. 2. Quick Burst Test -The pipe shall be designed to pass without failu r e a pressure of 400 psi applied in 60 to 70 ~econds when tested in accordance with ASTM Dl599. As referenced in ASTM D2241. 3. Sustai ned Pressure Test -The pipe shall be designed to pass without failure for 1,000 hours a pressure of 260 psi when tested in accordance with ASTM Dl598, as re f erenced in ASTM D2241 4. Acetone Immersion Test -After 20 min. immersion in a sealed container of anhydrous (99.5% pure) acetone a l" long sample ring s hall show no visible spalling or cracking (Swelling or softening is not a failure) when tested in accordance with ASTM 02152. 5. Vise Test -Place between 2 flat parallel plates a 2" and compress the outside diameter 60% in 2 to S min. be no evidence of splitting or shattering. B. Joints PVC pipe s h all be furnished with an elastomeric gasket long ring There shall joint and an integral thickened bell as part of each joint. Pipe and fittings must be assembled with a nontoxic lubricant. Provisions must be made at each joint for contraction and expansion. Refer to ASTM F477, D3139 and D3212. s .104/2 C. Fittings 1. Fittings for PVC water pipe shall be cast iron or ductile iron and shall conform to AWWA CllO, unless otherwise specified. See Specification Np. W.104.5 paragraphs C-G. 2. Fitting joints shall be push-on or mechanical joints .. Bolts and nuts for mechanical joints or flanged ends will be of a high strength corrosion resistant low-alloy steel and shall conform to AWWA Clll. Flange bolts and nuts for above ground installation shall conform to Appendix A of AWWA Cll5. Flange bolts and nuts for below ground installations shall be Type 304 or 316 stainless steel. All fittings shall be bituminous coated outside and cement-mortar lined inside with seal coat in accordance with AWWA Cl04. PVC to cast iron adapters will be used with cast iron fittings. 3. Polyethylene wrap or encasement of metal fittings shall conform to AWWA Cl05. Joint tape shall be self sticking PVC or polyethylene, 10 mils thick. D. Concrete for Blocking Encasement Cement shall meet ASTM Cl50, Type I. Aggregates shall meet ASTM C33. The twenty~eight (28) day compressive strength shall be 2,000 psi or more. S.104.6 INSPECTION, STORAGE AND HANDLING A. Refer to Specification No. SW.101 paragraphs C and D for general requirements. B. Unloading -Cold Weather Handling As the temperature approaches and drops below freezing extra care should be used in handling during cold weather. Pipe at the bottom of a stack may become out-of-round due to the weight of material above it. Allow the pipe to recover to full initial roundness before installation. Pipe may be unloaded by hand, either by passing over the side or off the truck end. Sliding one length on another is permissable in unloading pipe, but lengths in the bottom layer shall be lifted off of the rough surface of the truck body to avoid abrasion. Compact shipping units (palletized bundles in a wood frame) may be unloaded by conventional fork lifts. S.104/3 C. Stockpiles Store pipe on a flat surface so as to support the barrel evenly, with bell ends overhanging. Store randbm lengths separately where they will be readily available. Individual lengths of pipe should be stacked in piles no higher than 5 feet. Pipe shall be protected during long exposures (several months) to sunlight. Do not use clear plastic sheets. Provide for air circulation under sheet. D. Storing Rubber Rings Store all rubber rings at a central point and distribute them as needed. Keep them clean, away from oil, grease, excessive heat and electric motors which produce ozone. If rubber rings are not to be used immediately, store them in their cartons, as shipped, in a cool dark place out of the direct rays of the sun. S.104.7 CONSTRUCTION METHODS A. Trench Width Trench Widths shall not exceed those shown in Table 1. TABLE 1 Suggested Trench Widths at the Top of the Pipe* No minal Pipe Size in. Trench Width (in.) Max. Min. 4 28 20 6 30 22 8 32 24 10 34 26 12 36 28 *The trench should never be wider than the width used as design criterion. S.104/4 B. Pipe Installation 1. All pipe fittings, services and other appurtenances shall be examined carefully for damage and other defects immediately before installation. Defective materials shall be marked and held for inspection by the Engineer, who may prescribe corrective repairs or reject the materials. 2. All lumps, blisters, and other irregularities shall be removed from the socket and plain ends of each pipe, and the outside of the plain end and the inside of the bell shall be wiped clean and dry and be free from dirt, sand, grit, or any foreign material before the pipe is laid. 3. Foreign material shall be prevented from entering the pipe while it is being placed in the trench. During laying operations, no debris, tools, clothing, or other materials shall be placed in the pipe. 4. As each length of pipe is placed in the trench, the joint shall be assembled and the pipe brought to correct line and grade. The pipe shall be secured in place with approved backfill material. 5. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a watertight plug or other means approved by the Engineer. When practical, the plug shall remain in place until the trench is pumped completely dry. Care must be taken to prevent pipe flotation should the trench fill with water. C. Joint Assembly 1. Push-on joints shall be assembled as follows: a. Thoroughly clean the groove and bell socket and insert the gasket, making sure that it faces the proper direction and that it is correctly seated. b. After cleaning dirt or foreign material from the plain end to a point (l") inch beyond the reference work. Apply lubricant in accordance with the pipe manufacturer's recommendations. The lubricant is supplied in sterile cans and every effort si1ould be made to keep it sterile. S.104/5 c. Be sure that the plain end is beveled; square or sharp edges may damage or dislodge the gasket and cause a · leak. When pipe is cut in the field,"bevel the plain end with a heavy file or grinder to remove all sharp edges. Push the plain end into the bell of the ~ipe. Keep the joint straight while pushing. Brace bell while the bevel end is pushed under ring, so that previously completed joints in the line will not be closed up. Make deflection after the joint is assembled. d. Push the spigot end in until the reference mark on the spigot end is flush with the end of the bell. If undue resistance to insertion of the bevel end is encountered or the reference mark does not reach the flush position, d i sassemble the joint, and check the position of the ring. If it is twisted or pushed out of its seat, clean the ring, bell and bevel end and repeat the assembly steps. Be sure both lengths are in proper alignment. If the ring was not out of position, measure the distance between the reference mark and the bevel end and check it against correct values from the manufacturer. Relocate the reference mark if it is out of position. e. Small pipe can be pushed into the bell socket with a long bar. Large pipe require additional power, such as a jack, lever puller, or backhoe. A timber header should be used between the pipe and jack or backhoe bucket to avoid damage to the pipe. 2. Mechanical joints shall be assembled as follows: a. Wipe clean the socket and plain end. The plain end, socket, and gasket should be washed with a soap solution to improve gasket seating. b. Place the gland on the plain end with the lip extension toward the plain end, followed by the gasket with the narrow edge of the gasket toward the plain end of the pipe. c. Insert the pipe into the socket and press the gasket firmly and evenly into the gasket recess. Keep the joint straight during assembly. Make deflection after joint assembly but before tightening the bolts. d. Push the gland toward the bell and center it around the pipe with the gland lip against the gasket. S.104/6 e. Align bolt holes and insert bolts, with bolt heads behind the bell flange, and tighten opposite nuts to keep the gland square with the socket. f. Tighten the nuts in accordance with Table 2. 3. When it is necessary to deflect pipe from a straight line in either the vertical or horizontal plane, or where long radius curves are permitted, the amount of deflection shall not exceed that shown in Table 3. Pipe Diameter in. 4 6 8 10 12 TABLE 2 Mechanical Joint-Bolt Torques Bolt Diameter Torques in. ft-lb 5/8 45-60 3/4 75-90 1 85-100 1 1/4 105-120 TABLE 3 Maximum Deflectfon Full Length Pipe Push-on Type Joint Deflection Angle deg 5 5 5 5 5 Minimum Radius of Curve-ft.* 100 150 200 250 300 *The line should be assembled above ground, in a straight line, then curved and laid in the trench. All curvature results from the bending of the pipe lengths. There is no deflection at the joint. s. 104/7 4. Cutting and Beveling a. A square cut is essential to insure proper assembly. Use either a tubing cutter or a miter box and carpenter's fine-toothed hand saw or hacksaw. (Do not use standard pipe cutters. The cutting wheel will crush or damage the pipe.) b. Use a factory-finished beveled end as a guide to determine the angle and length of taper. The end may be beveled using a Pilot beveling tool which will cut the correct taper automatically or a thin steel, "cheese-grater" type of hand tool, Stanley "Surform" No. 399. c. With a pencil or crayon, locate the reference mark at the proper distance from the bevel end as indicated by the manufacturer. D. Polyethylene Tube Protection All cast iron and ductile iron fittings shall be provided with polyethylene tube protection. Completely cover all fittings and connections with polyethylene film held securely in place with joint tape or strapping per Specification No. S.103.7 paragraph D. E. Embedment Install embedment as shown in Part S.3 or on the plans. F. Reaction Anchorage and Blocking 1. Block, anchor or harness all piping subject to internal pressure to preclude separation of joints. Provide suitable reaction blocking, anchors, harnesses or other acceptable means for preventing movement of pipe caused by internal pressure for all unlugged bell and spigot or all-bell tees, Y-branches, bends deflecting 11-1/4 degrees or more, and plugs which are subject to internal pressure in excess of 10 psi. 2. Extend 2,000 psi concrete blocking from the fitting to solid undisturbed earth and install so that all joints are accessible for repair. The bearing area shall be as shown on the plans. If no details regarding blocking are shown on the plan, provide enough concrete bearing area against the ditch to limit soil loading to 2,000 psf from the thrust produced at an internal pressure in the pipe of 200 psi. S.104/8 3. If adequate support against ground cannot be obtained, install metal harness, anchorages consisting of steel rods across the joint and securely anchor ·to pipe and fitting or install other adequate anchorage facilities to provide necessary support. Should the lack of a solid vertical excavation face be due to improper trench excavation, the entire cost of furnishing and installing metal harness anchorages shall be borne by the Contractor. 4. Protect from corrosion all steel clamps, rods, bolts and other metal accessories used in reaction anchorages or joint harnesses subject to submergence or in direct contact with earth and not encased in concrete with two (2) coats of bituminous paint supplied to clean dry metal surfaces. G. Minimum Cover Minimum Cover shall be forty-two (42") inches below top of curb to top of pipe, or as otherwise directed by the Engineer. H. Deflection Test The sewer line shall be tested for deflection, after the trench has been backfilled, leakage tests have been completed and before any paving may be placed over the sewer line. The test shall consist of pulling a mandrel through each sewer line, similar to that shown in Part S.3. The outside diameter of the mandrel shall be 5% smaller than the inside of the sewer line. The testing mandrel shall be approved by the Engineer prior to conducting the test. Should the mandrel hang or otherwise fail to pass through the sewer, the sewer shall be uncovered, the defect corrected and the sewer retested for deflection. S.104.8 MEASUREMENT A. Pipe Pipe will be measured (by horizontal distance) from center of manhole to center of manhole, cleanout or end of pipe without deduction for the length of intermediate fittings, services, manholes or cleanouts. B . Fittings Fittings will not be considered a measured item. S .104/9 C. Concrete Thrust Blocking Concrete t hrust blocking will not be considered a measured item. D. Excavation, Embedment Materials and Backfill Refer to Specification No. WS.309.0 paragraph A. E. Leakage Test Refer to Specification No. S.102.6. F. Manholes Refer to Specification No. S.201. G. Cleanouts Refer to Specification No. S.202. H. Service Connections and Laterals Refer to S p ecification No. S.203. I. Deflection Test Deflection test will not . be considered a measured item. S.104.9 PAYMENT A. Pipe Payment will be made at the price bid per foot for furnishing and installing pipe, which bid price will include all costs for the complete pipe installation, including fittings, trenching and backfill, embedment, compaction or tamping, testing, and final cleanup and all other work not otherwise provided for in the bid proposal. B. Retainage for Incomplete Work for Partial Payments 1. Pipeline in place, but not backfilled, compacted, tested, cleaned, and/or right-of-way cleaned up, will not be considered 100% complete. The percent of pipe completed will be reduced by the following percentages: a. Incomplete backfill, compaction and cleanup -6%. b. Incomplete Leakage Test -2%. S.104/10 c. Incomplete Deflection Test -2%. 2. Monthly estimates will be paid by the linear foot of equivalent pipe properly placed, backfilled, compacted, tested, cleaned, and right-of-way cleaned up. END OF SPECIFICATION S.104/11 / SPECIFICATION NO. S.105 VITRIFIED CLAY PIPE AND FITTINGS S.105.1 DESCRIPTION This section describes the manufacture, construction and installation of vitrified clay pipe (VCP) and fittings. S.105.2 RELATED WORK SPECIFIED ELSEWHERE A. Part WS.3 -Excavating, Trenching and Backfilling B. Specification No. S.102 -Leakage Tests C. Specification No. S.201 -Manholes S.105.3 APPLICABLE STANDARDS ASTM -Cl2, C33, C43, Cl50, C301, C425, C700, C828 and C896 S.105.4 SUBMITTALS A. Submit manufacturer's data on pipe furnished i~dicating compliance with the specifications regarding dimensions, thickness, weights and materials. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with this specification. C. Submit complete details of the pipe joint to be used. Submit dead load and live load calculations for pipe with embedment classes shown on the plans (Ws=l20pcf, S.F.=1.5). D. The manufacturer shall review the plans and specifications to satisfy himself that his pipe will support the dead and live loads of this project without damages to the pipe for the t y pes of embedment called for on the plans. If the next higher class embedment is required, notify the Contractor and Engineer. The Contractor shall use the next higher class embedment without extra cost to the Owner, if the next higher embedment is required by the pipe manufacturer. S .105/1 S.105.5 MATERIALS A. Pipe B. 1. Vitrified clay pipe six (6") inches in diameter and larger shall conform to the current ASTM C700 standard. The minimum crushing strength (3 edge bearing strength) shall exceed the "extra strength" values given in Table 1 of ASTM C700. The minimum joint length shall be 5 feet. All pipe shall be new. 2. Each joint of pipe shall bear the initials or name of the manufacturer, and the location of the plant. The words "Extra Strength" or the symbol "ES" shall be included to identify the class of pipe. The markings shall be indented on the exterior of the pipe, and shall be plainly legible for identification. 3. The class embedment used shall be in accordance with Table 1. TABLE 1 Maximum Depth of Cover vs Embedment Class Nominal Class A Diameter, Class c Cl a ss B Modified, (in.) Ft. Ft. Ft. 6 18 20 24 8 14 16 20 10 12 14 20 12 10 14 16 15 10 14 18 18 8 12 16 21 8 12 16 24 10 14 20 Joints All pipe joints shall conform to the current ASTM C425 standard for compression joints. Pipe sizes six (6") inches through eighteen (18") inches shall be joined using a compression sl~eve. S.105 /2 C. Fittings All fittings shall conform to the current ASTM C700 st a ndard. Fittings shall correspond in all respects with the dimensions specified for pipe of the corresponding size. Joints shall all conform to ASTM C425 and paragraph B above. D. Concrete for Blocking or Encasement Cement shall meet ASTM Cl50, Type I. Aggregates shall meet ASTM C33. The twenty-eight (28) day compressive strength shall be 2000 psi or more. S.105.6 INSPECTION, STORAGE AND HANDLING A. General Refer to Specification No. WS.101 paragraph C and D for general requirements. B. Pipe Handling 1. Pipe and fittings shall be handled so as to protect them from damage, especially damage due to impact, shocks, and free fall. 2. Carefully examine each pipe and fitting before installation, for soundness and specification compliance. Pipe accepted may be plainly marked by the inspector. Rejected pipe shall not be defaced, but shall be replaced with pipe that meets specification. 3. Handle pipe so that premolded jointing surfaces or attached couplings do not support the weight of the pipe. Do not damage the jointing surfaces or couplings by dragging, contact with hard materials, or by use of hooks. C. Distribution of Pipe In distributing pipe at the site of the work, unload each piece opposite or near the place where it will be laid in the trench. Handle pipe on the side of the work parallel with the trench alignment with the bells facing the direction which the work will proceed unless otherwise directed. Keep the interior of all pipes, fittings and accessories free from dirt and foreign matter at all times. S.105/3 S.105.7 CONSTRUCTION METHODS A. Trench Width Trench Widths shall not exceed those shown in Table 2. TABLE 2 Suggested Trench Width at Top of Pipe* Nominal Pipe Size, Trench Width (in.) in. Max. Min. 6 32 24 8 34 26 10 36 28 12 39 31 15 42 36 18 45 37 21 49 41 24 52 44 27 56 48 30 59 51 33 63 55 36 66 58 42 75 67 *The trench should never be wider than ·the width used as design criterion. B. Pipe Installation 1. All pipe fittings and other appurtenances shall be examined carefully for damage and other defects immediately before installation. Defective materials shall be marked and held for inspection by the Engineer, who may prescribe corrective repairs or reject the materials. 2. All lumps, blisters, and other irregularities shall be removed from the socket and plain ends of each pipe, and the outside of the plain end and the inside of the bell shall be wiped clean and dry and be free from dirt, sand, grit, or any foreign material before the pipe is laid. 3. Foreign material shall be prevented from entering the pipe while it is being placed in the trench. During layout operations, no debris, tools, clothing, or other materials shall be placed in the pipe. S.105/4 4. As each length of pipe is placed in the trench, the joint shall be assembled and the pipe brought to correct line a nd grade. The pipe shall be secured in place with approved backfill material. 5. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a watertight plug or other means approved by the Engineer. When practical, the plug shall remain in place until the trench is pumped completely dry . Care must be taken to prevent pipe flotation should the trench fill with water. C. Joint Assembly 1. Clean joint contact surfaces innnediately prior to joining . Use joint lubricants and joining methods, as reconnnended by the pipe manufacturer. 2. Lubricate both joint surfaces, line up the socket and spigot, and shove the pipe together with a steady pressure. For small diameter pipe, this assembly can be done by hand. 3. For larger sizes, a bar may be used where a firm trench bottom permits. When using a bar, care should be taken not to damage the lip of the socket or coupling. Usually a wood block is used to cushion the bar pressure and eliminate breakage. 4. Under other conditions, a come-along or other special device may be required . When using a come-along, the spigot must be properly positioned in the bell before exerting pressure. 5. For large diameter pipe, a hairpin, "J" hook, sling or other approved device can be used to hold the weight o f the pipe of f the trench bottom. The pipe can then be drifted into position by adjusting the position of the boom of the machine. 6. Unless otherwise required, lay all pipe straight between chan ges in alignment and at uni f orm grade between changes in grade. Excavate bell holes for each pipe joint. When joined in the trench, the pipe shall form a true and smooth line. 7. Whenever practicable, start pipe laying at the lowest point and install the pipe so that the spigot ends point in the direction of flow to prevent bedding material f rom entering the j oint. S.105/5 8. After each pipe has been brought to grade, aligned, and placed in final position, deposit and shovel slice or spaqe bedding material under the pipe haunches. Wyes and tees shall be bedded to prevent shear loading. 9. Pipe deflections at the joint shall be equal to or less than that sho'Wil in Table 3. TABLE 3 Deflection Nominal Diameter, Deflection of Pipe, in. in. /linear ft. 3 to 12 incl 1/2 15 to 24 incl 3/8 27 to 36 incl 1/4 39 and 42 3/16 D. Adapters Use watertight adapters to connect to ductile iron, PVC, A-C or any other dissimilar pipe material to make a watertight connection. E. Minimum Cover S.105.8 Minimum Cover shall be as follows: 6" through 12", 42" cover; 15" through 36", 72" cover as measured below top of curb to top of pipe, or as directed by Engineer. REMOVAL OF PIPE OR FITTING Remove any pipe or fittings that fail to meet the following requirements: A. Variations in any dimension exceeding the permissable variations published by the pipe manufacturer. B. A piece broken out of the bell or spigot end of such size that the watertightness of the joint would be impaired. C. Cracks in the pipe. D. Fa ilure of the pipe to go completely "home" due to binding of the spigot against the bell. E. Failure to p a ss any of the tests required by these speci f ic a tions. S.105/6 S.105.9 MEASUREMENT A. Pipe will be measured (by horizontal distance) from center of manhole to center of manhole, cleanout or end of pipe without deduction for the length of intermediate fittings, services, manholes or cleanouts. B. Fittings Fittings will not be considered a measured item. C. Concrete Blocking Concrete blocking will not be considered a measured item. D. Excavation, Embedment Materials and Backfill Refer to Specification No. WS.309 paragraph A. E. Leakage Test Refer to Specification No. S.102.6. F. Manholes Refer to Specification No. S.201. G. Cleanouts Refer to Specification No. S.202. H. Service Connections and Laterals Refer to Specification No. S.203. S.105.10 PAYMENT A. Pipe Payment will be made at the price bid per foot for furnishing and installing pipe, which bid price will include all costs for the complete pipe installation, including fittings, trenching and backfill, embedment, compaction or tamping, testing, final cleanup and all other work not otherwise provided for in the bid proposal. S.105/7 B. Retainage for Incomplete Work for Partial Payments 1. Pipeline in place, but not backfilled, compacted, tested, cleaned, and/or right-of-way cleaned up, will not be considered 100% complete. The percent of pipe or boring and tunneling completed will be reduced by the following percentages: a. Incomplete backfill, compaction and cleanup -6%. b. I n complete Leakage Test -2%. 2. Monthly estimates will be paid by the linear foot of equivalent pipe properly place, backfilled, compacted, tested, cleaned, and right-of-way cleaned up. END OF SPECIFICATION S.105/8 SPECIFICATON NO. S. 106 / REINFORCED CONCRETE PIPE AND FITTINGS S.106.1 DESCRIPTION This section describes the manufacture, construction and installation of reinforced concrete pipe (RCP) and fittings. S.106.2 RELATED WORK SPECIFIED ELSEWHERE A. Part WS.3 -Excavating, Trenching and Backfilling B. Specification No. S.102 -Leakage Tests C. Specification No. S.201 -Manholes S.106.3 APPLICABLE STANDARDS ASTM -C33, C76, C150, C443, C497, C655 and C822 S.106.4 SUBMITTALS A. Submit manufacturer's data on pipe furnished indicating compliance with the specifications regarding dimensions, thickness, weights and materials. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with the specification. C. Submit complete details of the pipe joint to be used. Submit dead load and live load calculations for pipe with embedment classes shown on the plans (Ws=120 pcf, S.F.=1.5) D. The manufacturer shall review the plans and specifications to satisfy himself that his pipe will support the dead and live loads of this project without damages to the pipe for the types of embedment called for on the plans. If the next higher class embedment is required, notify the Contractor and Engineer. The Contractor shall use the next higher class embedment without extra cost to the Owner, if the next higher embedment is required by the pipe manufacturer . S .106/1 S.106.5 MATERIALS A. Pipe 1. Reinforced concrete pipe manufactured under these specifications shall conform to the current specifications for "Reinforced Concrete Culvert, Storm Drain and Sewer Pipe," ASTM C76 or ASTM C655, with the following additions: a. All pipe shall be machine made by a process which will provide for ~niform placement of zero slump concrete in the f orm and compaction by mechanical devices which will assure a dense concrete in the finished product. b. Aggregates for the concrete shall consist of limestone aggregates in the proportion to provide a minimum calcium carbonate equivalent of 65%. c. Pipe manufactured according to these specifications shall be of five classes identified as Class I, Class II, Class III, Class IV and Class V. d. Minimum wall thickness shall be as for "Thick Wall" pipe. e. Minimum laying length of each joint shall be 6'-0" for sizes up to and including 15" diameter and 7'-6" for sizes larger than 15" diameter except for bends, wyes, and other special fittings which may be required, or for special radius pipe. f. Pipe furnished under this specification shall be steam cured in accordance with methods prescribed in ASTM C-76 except that the steam curing time shall be not less than 8 continuous hours. Pipe may be transported to the job three days after the prescribed steam curing period, provided it successfully meets all physical load test requirements. g. The pipe and connecting joints shall be subject to the hydrostatic tests set forth in the current specifications for "Joints for Circular Concrete Sewer and Culvert Pipe, Using Flexible, Water-Tight, Rubber-Type Gaskets," ASTM C443, both for "Pipes in Straight Alignment" and for "Pipes in Maximum Deflected Position," without leakage either in the pipe or in the joints. h. No lift holes are allowed. S.106/2 2. Steel Reinforcement a. All steel reinforcement shall be in accordance with ASTM C76 and shall be circular in shape. No elliptical reinforcement will be permitted. Where .Class III pipe of sizes larger than 30" diameter are specified, the manufacturer may at its option furnish pipe manufactured with either Wall "B" or Wall "C" minimum thickness and the applicable minimum steel area as listed for circular cages in Table II of ASTM C76, provided test strength requirements for Class III pipe are satisfactorily met. "Thick Wall" pipe shall be furnished. b. Where Class IV or V pipe is specified, the steel as called for in the wall as designated will be furnished. Quadrant reinforcement will be acceptable. As an alternate the pipe may be designed as detailed in specifications for "Reinforced Concrete, C-Load, Culvert, Storm Drain, and Sewer Pipe," ASTM C655. Proof of design must be submitted. 3. Thick Wall Pipe Shall Be Required The basic physical dimensional design for Thick Wall pipe shall be identical to the next larger 3-inch increment standard pipe size up through and including 51-inch pipe covered by these specifications, reduced internally to the inside diameter as specified on. the plaqs. The reinforcing steel shall be listed in the tables for the internal diameter unless a special design is submitted under Section 10 of ASTM C76 or under specifications _ for "Reinforced Concrete, D-Load, Culvert Storm Drain, and Sewer Pipe," ASTM C655. Proof of design must be submitted. The steel shall be placed as required for the next larger size to provide and additional sacrificial lining of 1.5 inches of concrete cover over the reinforcing steel. 4. The class embedment used for various depths of cover are shown on the plans. 5. Marking a. The following information shall be clearly marked on each section of pipe: 1) The pipe class and specification designation. 2) The date of manufacture. S.106/3 3) The name or trademark of the manufacturer, and 4) Identification of plant. b. One end of each section of pipe with elliptical or quadrant reinforcement shall be clearly marked during the process of manufacturing or inunediately thereafter, on the inside and the outside of opposite walls along the minor axis of the elliptical reinforcing or along the vertical axis for quadrant reinforcing. c. Markings shall be indented on the pipe section or painted thereon with water-proof paint. B. Joints 1. Connecting joints shall be made using a flexible watertight rubber-type compression gasket. The rubber gasket shall be the major element of the joint depended upon to provide watertightness. a. Rubber Gaskets -All rubber-type gaskets shall be of the round "O" Ring design, conforming to ASTM C443~ The gasket shall be continuous ring which when in position in the gasket "seat" on the spigot or tongue end of the pipe shall not be stretched more than 25 per cent of its original circumfe.rence. The gaskets shall be the product of a manufacturer having a successful experience record of at l east five (5) years in the manufacture of rubber gaskets for concrete pipe joints. b. Joint Design -The joint design shall consist of a bell on one end of a unit of pipe, and a spigot on the adjac e nt end of the joining pipe. c. Joint Approval -Joint designs and type of rubber gaskets shall be subject to approval by the Engineer prior to installation. 2. The spigot shall be so shaped as to provide a groove within which the gasket will b.e largely confined when compressed. The joint shall be designed such that the gasket is not required to support the weight of the pipe, and shall be such that when the joint is in normally closed position and when there is concrete-to-concrete contact between the outer surface of the spigot and the inner surface of the bell, including manufacturer's tolerances, the minimum annular space at the gasket seat shall not be less than SO percent of the S.106/4 uncompressed diameter of the gasket, nor more than 80 percent of the uncompressed thickness of the applied gasket. The uncompressed thickness is defined as the smallest cross-section of the round gasket. 3. If the joint leaks, repair joint to comply with leakage tests. C. Fittings and Specials Component parts for all fittings and specials such as bends, wyes, tees, etc. shall be manufactured on machines and in the same manner as straight joint concrete sewer pipe under these specifications, except that joint lengths may be shorter than minimum listed. The quality of the concrete, workmanship and bell and spigot joint detail for rubber gasket joints will be subjected to the same requirements as straight joints of pipe. D. Concrete for Blocking or Encasement Cement shall meet ASTM Cl50, Type I. Aggregates shall meet ASTM C33. The twenty-eight (28) day compressive strength shall be 2000 psi or more. S.106.6 INSPECTION, STORAGE AND HANDLING A. General Refer to Specification N~. WS.101 Paragraphs C and D for general requirements. B. Pipe Handling 1. Pipe and fittings shall be handled so as to protect them from damage, especially damage due to impact, shocks, and free fall. 2. Carefully examine each pipe and fitting before installation, for soundness and specification compliance. Pipe accepted may be plainly marked by the inspector. Rejected pipe shall not be defaced, but shall be replaced with pipe that meets specification. 3. Handle pipe so that premolded jointing surfaces or attached couplings do not support the weight of the pipe. Do not damage the jointing surfaces or couplings by dragging, contact with hard materials, or by use of hooks. S.106/5 . I C. Distribution of Pipe In distributing pipe at the site of the work, unload each piece opposite or near the place where it will be laid in the trench. Handle pipe in such a manner that damage to the p.ipe is prevented. Place pipe on the side of the work parallel with the trench alignment with the bells facing the direction which the work will proceed unless otherwise directed. Keep the interior of all pipes, fittings, and accessories free from dirt and foreign matter at all times. S.106.7 CONSTRUCT I ON METHODS A. Trench Width Trench Wi d ths shall not exceed those shown in Table 1. TABLE 1 Suggested Trench Width at Top of Pipe* Nominal Pipe Size, Trench Width (in.) in. Max. Min. 21 57 49 24 60 52 27 64 56 30 67 59 33 71 63 36 78 70 39 81 73 42 84 76 45 87 79 48 90 82 *The trench should never be wider than the width used as design criterion. S.106/6 B. Pipe Installation 1. All pipe fittings and other appurtenances shall be examined carefully for damage and other defects immediately before installation. Defective materials shall be marked and held for inspection by the Engineer, who may prescribe corrective repairs or reject the materials. 2. All lumps, blisters, and other irregularities shall be removed from the socket and plain ends of each pipe, and the outside of the plain end and the inside of the bell shall be wiped clean and dry and be free from dirt, sand, grit, or any foreign material before the pipe is laid. 3. Foreign material shall be prevented from entering the pipe while it is being placed in the trench. During layout operations, no debris, tools, clothing, or other materials shall be placed in the pipe. · 4. As each length of pipe is placed in the trench, the joint shall be assembled and the pipe brought to correct line and grade. The pipe shall be secured in place with approved backfill material. 5. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a watertight plug or other means approved by the Engi~eer. When practical, the plug shall remain in place until the trench is pumped completely dry. Care must be taken to prevent pipe flotation should the trench fill with water. C. Joint Assembly 1. Clean joint contact surfaces immediately prior to joining. Use joint lubricants and joining methods, as recommended by the pipe manufacturer. 2. Lubricate both joint surfaces, line up the socket and spigot, and shove the pipe together with a steady pressure. 3. A come-along or other special device may be required. When using a come-along, the spigot must be properly positioned in the bell before exerting pressure. S.106/7 4. A hairpen, "J" hook, sling or other approved device can be used to hold the weight of the pipe off the trench bbttom. The pipe can then be drifted into position by adjusting the position of the boom of the machine. 5. Unless otherwise required, lay all pipe straight between changes in alignment and at uniform grade between changes in grade. Excavate bell holes for each pipe joint. When joined in the trench, the pipe shall form a true and smooth line. 6. Whenever practicable, start pipe laying at the lowest point and install the pipe so that the spigot ends point in the direction of flow to prevent bedding material from entering the joint. 7. After each pipe has been brought to grade, aligned, and placed in final position, deposit and shovel slice or spade bedding material under the pipe haunches. Wyes and tees shall be bedded to prevent shear loading. S.106/8 D. Adapters Use watertight adapters to connect to ductile Jron, PVC, A-C or any other dissimilar pipe material to make a watertight connection. E. Minimum Cover S.106.8 Minimum Cover shall be seventy -two (72") inches below top of curb to top of pipe, or as directed by Engineer. REMOVAL OF PIPE OR FITTINGS Remove any pipe or fittings that fail to meet the following requirements: A. Variations in any dimension exceeding the permissible variations prescribed. B. A piece broken out of the bell or spigot end of such size that the watertightness of the joint would be impaired. C. Any shattering or flaking of concrete or other conditions indicating an improper concrete mix. D. Lack of uniformity in placement of steel which might preclude all joints being typical .of those tested. E. Cracks sufficient to impair the strength, durability or serviceability of the pipe. F. The complete absence of distinct web-like markings, which may be indicative of a deficiency of water in the concrete mix, from the external surface of the pipe made by any process in which the forms are removed immediately after the concrete has been placed unless specimens submitted for test that do not have such web-like markings shall have passed the physical tests required by these specifications. G. Failure of pipe to go completely "home" due to binding of spigot against bell or tongue against groove. H. Joint sections with spalls, cracks, fractures, or other imperfections that could adversely affect the performance of the joint. I. Failure to conform with any of the specifications herein set forth or referenced. S.106/9 S.106.9 MEASUREMENT A. Pipe will be measured (by horizontal distance)· from center of manhole to center of manhole, c l eanout or end of pipe without deduction for the length of intermedial fittings; services, manholes or cleanouts. B. Fittings Fittings will not be considered a measured item. C. Concrete Blocking Concrete b l ocking will not be considered a measured item. D. Excavation, Embedment Materials and Backfill Refer to Specification No. WS.309 paragraph A. E. Leakage Test Refer to Specification No ~ W.102.6 F. Manholes Refer to Specification No. S.201. G. Cleanouts Refer to Specification No. S.202. H. Service Connections and Laterals Refer to Specification No. S.203. S.106.10 PAYMENT A. Pipe Payment will be made at the price bid per foot for furnishing and installing pipe, which bid price will include all costs for the complete pipe installation, including fittings, trenching and backfill, embedment, compaction or tamping, testing, final cleanup and all other work not otherwise provided for in the bid proposal. S.106/10 B. Retainage for Incomplete Work for Partial Payments 1. Pipeline in place, but not backfilled, comp~cted, tested, cleaned, and/or right-of-way cleaned up, will not be considered 100% complete. The percent of pipe completed will be reduced by the following percentages: a. Incomplete backfill, compaction and cleanup - 6 %. b. Incomplete Leakage Test -2%. 2. Monthly estimates will be paid b y the linear foot of equivalent pipe properly placed, backfilled, compacted, tested, cleaned, and right-of-way cleaned up. END OF SPECIFICATION S .106/11 Work to be performed under Part S includes materials, labor a nd superintendence required to install a complete sewer line, inc luding manholes, appurtenances and an y other components required to c o nstruct a complete system. PART S.2 MISCELLANEOUS APPURTENANCES SPECIFICATION NO. S.201 MANHOLES S.201.1 DESCRIPTION This section describes the manufacture, construction and installation of sanitary sewer manholes. S.201.2 RELATED WORK SPECIFIED ELSEWHERE A. Specification No. WS.304 -Materials for Embedment B. Part S.l -Sanitary Sewer Mains C. Part S.3 -Standard Details S.201.3 APPLICABLE STANDARDS ASTM -A48, C32, C33, C76, Cl50 and C478 S.201.4 SUBMITTALS A. Submit manufacturer's data on materials furnished indicating compliance with the specifications regarding dimensions, thick- ness, weights and materials. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with this specification. S.201.5 MATERIALS A. Concrete Cement shall conform to the current ASTM Cl50 standard and be Type I. Aggregates shall conform to the current ASTM C33 standard and shall consist of limestone aggregates in the proportion to pro- vide a minimum calcium carbonate equivalent of 65%. Twenty-eight (28) day strength shall be equal to or greater than 3000 psi for cast-in-place concrete. Concrete for pre-cast manholes shall be 4000 psi. B. Manhole Rings and Covers Manhole rings and covers shall be manufactured of Class 30 gray cast iron conforming to ASTM A48 standard. Minimum total weight for ring and cover shall be 300 psi. Pick holes are prohibited. Furnish cast pick lugs. Lid shall have the work "SEWER" cast in it. Ring and covers shall be Samsco Standard Heavy Manhole Ring and Cover No. 50 or approved equal. S.201/1 C. Bricks and Mortar Bricks shall conform to the current ASTM C32 standard, Grade MM. Mortar for laying bricks shall be composed of. one part cement and two parts sand. Mortar joints shall be 1/2 inch thick. D. Grade Rings Grade rings shall be brick or precast reinforced concrete. Minimum thickness shall be 2 inches by 8 inches wide by 24 inches inside diameter. E. Precast Reinforced Manhole Sections Precast manhole sections shall conform to the current ASTM C478 standard. Joints shall be 0-ring gasketed. In lieu of the thickne s s as specified in C478, Section 7, DESIGN, the minimum wall thickness for manhole risers shall be as listed under wall "B" in the "Class Tables" of ASTM C76, Reinforced Concrete Pipe. F. Cast-In Place Forms Cast-in place manholes shall use forms equal to ABS Plastic Forms as marketed by I.C.M. Inc., Box 685, Jacksonville, Arkansas, or approved equal. Manholes shall be constructed of 3000 psi concrete with walls of 6 inches minimum thickness. Conical sections may be cast-in p lace o~ precast per paragraph S.201.4, E above. ·G. Drops Drops shall be constructed of ductile iron, PVC or VCP material specified in Part S.1 Sanitary Sewers, encased in concrete as shown in Part S.3 or on the plans. S.201.6 INSPECTION, STORAGE AND HANDLING A. Refer to Specification No. WS.101 paragraph C and D for general requiremen ts. B. Inspect the subgrade to made sure a suitable foundation for the manhole exists. Remove all debris, muck and water, or any sub- stance wh i ch would be detrimental to the strength of the foundation. C. If the cast-in place manholes are used, clean forms and lubricate with a form lubricant recommended by the form manufacturer. S.102.7 METHODS OF CONSTRUCTION A. Manhole Bases 1. Construct manhole bases in the configuration shown in Part S.3 and/or on the plans. Minimum thickness below the flowline of sewer shall be 8 inches or as shown on the Details. S.201/2 2. Insure that bases are constructed on firm ground and that ground water is controlled. Install crushed stone (standard gradation or larger) to stabilize bottom if directed to do so by Engineer. 3. The invert of manholes shall be formed in such a fashion that they are smooth and will not obstruct 'flow of sewage. Provide flow channels in the manhole base equivalent to the top of the pipe by forming the concrete base and trow- elling it to a smooth, even finish with a steel trowel. Slope the manhole bottom from the wall line to the flow channel and trowel it smooth on a grade of 1 inch per foot with a liberal radius applied at flow channel intercepts. 4. Cradle in concrete the first joint of pipe extending from the manhole in the same pour as that for the manhole base slab. A short joint will be used for this purpose. B. Brick Manholes 1. All beds and joints of mortar shall be full and completely filled. The outside of brick manholes shall be plastered and trowelled smooth with 1/2 inch of mortar. Joints shall be struck flush on inside of manholes. 2. Bricks shall be clean and wetted before laying. Every fifth course shall be laid in such a manner as to effect a tie between such course and the courses immediately thereunder. In general, the long ax.is of the tie course will be perpen- dicular to the long axis of the preceeding four courses. C. Precast Manholes 1. Cast bottom section of precast manhole riser ring in manhole base as shown in Part S.3 or on the plans. Place Synko-Flex waterstop per manufacturer's recommendations prior to setting precast starter ring. 2. Prior to placing each section of manhole riser or cone, thoroughly clean the bells and spigots to be joined. 3. Carefully place the 0-ring gasket and check for proper . alignment. 4. Plug lift holes and joints with "Water Plug" grout. D. Cast-In Place Manholes 1. Base The base shall be cast monolithically with the rest of the manhole. The invert and flow channel shall be formed during or irrunediately after the placing of the concrete and brush- finished as soon as the concrete has sufficiently set. The concrete must set for 24 hours before any pipe inside of the manhole is trinuned. S.201/3 The base concrete shall be 3000 psi, maximum slump 4 inches, vibrated or tamped on undisturbed bearing. The base shall have a minimum diameter 8 inches greater than the outside diameter of the manhole, and a minimum thickness including the area under the pipe as follows: 0 to 8' manhole 8" 8' to 12' manhole 10" 12' and above 12" 2. Invert All invert channels shall be smooth and accurately shaped to a semi-circular bottom conforming to the outside of the adja- cent sewer section. Inverts shall be formed directly in the concrete of the manhole base or may be constructed by laying full sect i on sewer pipe straight through the manhole and breaking out the top half after the base is constructed. In- verts shall extend up at least half of the diameter of the pipe. ,Changes in the direction of the sewer and entering branches shall have a true curve of as large a radius as the size of the manhole will permit. Where the pipe is laid through the manhole, the invert shall be finished to 1/4 inch below the c enter of the pipe. The pipe shall be trimmed· down to 1/4 inch below the surface of the invert, and the edges of the pipe along the invert and at the walls of the manhole shall be plastered and brush-finished.· Plaster shall be 2 parts of masonry sand to l part of Portland cement. 3. Steps Manhole steps will be at 15 inches on center as shown in Part S.3 or on the plans. In general steps will be located 90 degrees from the direction of flow of the manhole and will not be over or opposite a major pipe. A sample of the step must be provided before the forms reach the job site. 4. Manhole Barrel Section The vertical form_s, wall spacers, steps and placing cone must be carefully positioned and firmly clamped in place before any placement is made. The wall spacers must be located 90 degrees from each other. The manhole shall be cast of 3000 psi concrete with a maximum slump of 4 inches. The first placement shall consist of approximately 1/2 yard of concrete deposited evenly around the walls and vibrated until there is a minimum slope of 90 degrees from the bottom of the form to the bearing surface both inside and outside of the manhole. When this is complete and before additional concrete is added, the concrete must be carefully vibrated on each side of each pipe. Add i tional concrete must be deposited in evenly distri- buted layers of about 18 inches with each layer vibrated to bond it to the preceeding layer. The wall spacers must be S.201/4 raised as the placements are made with the area from which the spacer is withdrawn being carefully vibrated. Excessive vibra - tion is to be avoided. A maximum of 2% calcium chloride ma y be added to the concrete, at the contractor's option, to speed the set. The forms may be removed as soon as the concrete has sufficiently set (approximately 2 hours after placement). Form marks and offsets up to 1 inch will be permitted on the outside surface of the manhole. Form marks and offsets up to 1/2 inch will be permitted inside of the manhole. All offsets on the inside surface of the manhole will be smoothed and plas- tered so there is no projection or irregularity capable of scratching a worker or catching and holding water or solid materials. Honeycombs will be plastered with a mortar con- sisting of 3 parts of masonry sand to 1 part Portland cement inunediately upon removal of the forms. 5. Ring and Cover The ring and cover shall be cast monolithically with the manhole for those manholes not to be adjusted. All other manholes shall have the ring and cover set as shown in Part S.3 or on the plans. 6. Backfilling Backfilling will be performed evenly and carefully around the manhole after the full .strength of the concrete is attained. 7. Cold Joints Should circumstances make a cold joint necessary, a formed groove or reinforcing dowels (115 bars x 36" long on 12" centers) will be required in the top of the first placement for shear protection. Immediately before the second placement is made, the surface of the cold joint shall be thoroughly cleaned, a layer of Synko-Flex waterstop placed in the groove and wetted with a layer of mortar being deposited on the surface. 8. Construction Joints A construction joint shall be provided for 6 foot diameter manholes as shown in Part S.3 or on the plans. In addition, manholes deeper than 15 feet may have a construction joint for ease and safety in concrete placement. A formed groove or re- inforcing dowels (116 bars x 36" long on 12" centers) will be required in the top of the first placement for shear protection. Immediately before the second placement is made, the surface of the cold joint shall be thoroughly cleaned, a layer of Synko- Flex waterstop placed in the groove and wetted with a layer of mortar being deposited on the surface. E. Install grade ring s and manhole ring covers a s shown in Pa rt S.3 or on the plans. S.2 01/5 F. Corrosion resistant steps shall be placed in the walls at a vertical distance of 18 inches on centers beginning at a point not great er than 3 feet from flow line of sewer, and shall be · installed continuously to within not less than·9 inches of top of the work. Where the concrete is used in wall construction these steps shall be cast in the wall at time concrete is placed. G. Where inlet leads, main or lateral pipe sewers enter manholes, pipes shall be cut off flush with inside of manhole and any irregularities shall be pointed up with mortar. H. If manholes are constructed in streets where immediate subsequent paving or re-paving is involved, readjust the manhole ring and covers, after the paving operation is complete. I. Each manhole shall be tested individually by exfiltration, or infiltrat i on in areas of high groundwater. The maximum allowable leakage shall be 1/10 of a gallon per hour per foot diameter per foot of head. If manhole does not pass leakage test, then Contractor shall take whatever remedial work necessary to cause manholes to pass this leakage test. J. Drops shall be constructed as shown in Part S.3 or on the plans. Concrete for encasement shall have a twenty-eight (28) day strength of 2000 psi. Ductile iron pipe and fittings shall be wrapped per Specification No. S.103.7 D. S.201.8 MEASUREMENT A. Standard Depth Manholes The depth of manholes completed shall be determined by measuring the vertical distance from the flow line of the sewer main to the top of the manhole ring and cover. All manholes with a depth from 4 feet up to and including 8 feet shall be designated as Standard Manholes. Standard manholes will be measured by the each for the various size diameters. B. Shallow Manholes Manholes with a depth less than 4 feet shall be designated Shallow Manholes and will be measured by the each for the various size diameters. C. Extra Depth Manholes Manholes with a depth greater than 8 feet shall be designated Extra Depth Manholes and will be measured by the linear depth over 8 feet for the various size diameters. S .201/6 D. Manhole Drops The depth of manhole drops completed shall be determined by measuring the vertical distance from the flow line of the hprizontal portion of the tee to the flow line of the sewer main. Drops up to and in- cluding 3 feet shall be designated Standard Manhole ·Drop. Standard manhole drops will be measured by the each for the various size diameters. E. Extra Depth Manhole Drops Manhole drops with a depth greater than 3 feet shall be designated Extra Depth Manhole Drops and will be measured by the linear depth over 3 feet for the various size diameters. S.201.9 PAYMENT A. Standard Depth and Shallow Manholes Payment will be made at the unit price bid per each for furnishing and installing Standard Depth and Shallow Manholes, which bid price shall include all costs for the complete manhole installation includ- ing all materials, labor, equipment, excavation, foundation, backfill, testing, clean up and incidentals necessary for a complete _installa- tion for the various classification of manholes. B. Extra Depth Manholes Payment will be made at the unit price bid per linear foot for furnishing and installing Extra Depth Manholes, which bid price shall include all costs for the furnishing and installing of all materials, labor, equipment, and incidenials necessary for a complete installation. C. Manhole Drops Payment will be made at the unit price bid per each for furnishing and installing manhole drops, which bid price shall include all costs for the complete drop installation including all labor, equipment, materials and incidentals in addition to Standard, or Extra Depth Manholes for a complete installation. D. Extra Depth Manhole Drops Payment will be made at the unit price bid per linear foot for furnishing and installing Extra Depth Manhole Drops, which bid price shall include all costs for extra depth drop installation including all labor, equipment, materials and incidentals in addition to man- hole drops for a complete installation. E. Retainage for Incomplete Work for Partial Payments 1. Manholes and manhole drops in place but not backfilled, compacted, tested, cleaned, and/or right-of-way cleaned up, will not be s .201/7 considered 100% complete. The percent of manhole or manhole drop completed will be reduced by the following percentages: a. Incomplete backfill, compaction and clean up -6%. b. Incomplete leakage test - 2%. 2. Monthly estimates will be paid by the each or linear foot of equivalent manhole or manhole drop properly placed, backfilled, compacted, tested, cleaned and right-of-way cleaned up. END OF SPECIFICATION S .201/8 SPECIFICATION NO. S.202 CLEAN OUTS S.202.1 DESCRIPTION This section describes the manufacture, construction and installation of sanitary sewer cleanouts. S.202.2 RELATED WORK SPECIFIED ELSEWHERE A. Specification No. WS.304 -Materials for Embedment B. Part S.l -Sanitary Sewer Mains C. Part S.3 -Standard Details S.202.3 APPLICABLE STANDARDS ASTM -A48, C33 and Cl50 S.202.4 SUBMITTALS A. Submit manufacturer's data on materials furnished indicating compliance with the specifications regarding dimensions, thick- ness, weights and materials _. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with this specification. S.202.5 MATERIALS A. Concrete for Blocking Cement shall conform to the current ASTM CSO standard and be Type I. Aggregates shall conform to the current ASTM C33 standard. Twenty-eight (28) day strength shall be equal to or greater than 2000 psi. B. Sewer Cleanout and Cover Sewer cleanouts and covers shall be manufactured of gray cast iron conforming to ASTM A48 standard. Lid shall have the word "SEWER" cast in it. Cleanouts and covers shall be manufactured by Samsco. S.202.6 INSPECTION, STORAGE AND HANDLING A. Refer to Specification No. WS.101 paragraph C and D for general requirements. S .202/l B. Inspect the subgrade to make sure a suitable foundation for the cleanout exists. Remove all debris, muck and water, or any sub- stance which would be detrimental to the installation. S.202.7 METHODS OF CONSTRUCTION Install and construct sanitary sewer cleanouts as shown in Part S.3 or on the plans. S.202.8 MEASUREMENT Cleanouts will be measu r ed by the each for the various size listed in the proposal. S.202.9 PAYMENT A. Cleanouts Payment will be made at the unit price bid per each for furnishing and installing cleanouts, which bid price shall include all costs for the complete cleanout installation including all materials, labor, equipmen t, excavation, piping, backfill, testing, clean up and incidentals from sewer main to cast iron cleanout. B. Retainage for I ncomplete Work for Partial Payments 1. Cleanouts in place but not backfilled, compacted, tested, cleaned, and/or right-of-way cleaned up, will not be considered 100% complete. The percent of cleanout completed will be re- duced by the following percentages: a. Incomplete backfill, compaction and clean up -6%. b. Incomplete leakage test - 2%. 2. Monthly estimates will be paid by the each of equivalent cleanout properly placed, backfilled, compacted, tested, cleaned and right-of-way cleaned up. END OF SPECIFICATION S.202/2 _j SPECIFICATION NO. S.203 SERVICE CONNECTIONS AND LATERALS S.203.l DESCRIPTION This section describes the manufacture, construction and installation of sanitary sewer service connections and laterals. S.203.2 RELATED WORK SPECIFIED ELSEWHERE A. Specification No. WS.304 -Materials for Embedment B. Part S.l -Sanitary Sewer Mains C. Part S.3 -Standard Details S.203.3 APPLICABLE STANDARDS ASTM -C33, Cl50, Dl557, Dl748 and D2241 S.203.4 SUBMITTALS A. Submit manufacturer's data on pipe furnished indicating compliance with the specifications regarding dimensions, thickness, weights and materials. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with this specification. S.203.5 MATERIALS A. Concrete for Blocking Cement shall meet ASTM Cl50, Type I. Aggregates shall meet ASTM C33. The twenty-eight (28) day compressive strength shall be 2000 psi or more. B. Service Connections Service connections shall be standard sewer fittings manufactured of the same material as the sewer main. C. Laterals 1. Pipe Lateral pipe shall be four (4") inches in diameter and larger PVC pipe which shall conform to ASTM D2241 standard and NSF approved class 1245-A PVC compound conforming to ASTM Dl788. PVC pipe wall thickness shall be Schedule 40 or SDR 21 and the outside diameter shall be the same as steel pipe. S.203/1 2. Joints Lateral pipe joints shall be furnished with a solid sleeve . coupling and solvent welded, or integral thicknened bell with elastorneric gasket. 3. Fittings Fittings shall be Schedule 40 or SDR 21 PVC. S.203.6 INSPECTION, STORAGE AND F.ANDLING A. Refer to Specification No. WS.101 paragraph C and D for general requirements. B. Unloading -Cold weather Handling As the temperature approaches and drops below freezing, extra care should be used in handling during cold weather. Pipe at the bottom of a stack may become out-of-round due to the weight of material above it. Allow the pipe to recover to full initial roundness be- fore installation. Pipe may be unloaded by hand, either by passing over the side or off the truck end. Sliding one length on another is permissible in unloading pipe; but lengths in the bottom layer should be lifted off of the rough surface of the truck body to avoid abrasion. Compact shipping units (palletized bundles in a wood frame) may be unloaded by conventional fork lifts. C : Stockpiles Store pipe on a flat surface so as to support the barrel evenly, with bell ends overhanging. Store random lengths separately where they will be readily available. Individual lengths of pipe should be stacked in piles no higher than 5 feet. Pipe shall be pro- tected during long exposures (several months) to sunlight. Do not use clear plastic sheets and provide for air circulation under sheet. D. Storing Rubber Rings Store all rubber rings at a central point and distribute them as needed. Keep them clean, away from oil, grease, excessive heat and electric motors which produce ozone. If rubber rings are not to be used immediately, store them in their cartons, as shipped, in a cool dark place out of the direct rays of the sun. S.203.7 CONSTRUCTION METHODS A. Trench Width Trench width shall not exceed twenty-f our (24") inches for latera l s . S.2 03/2 B. '.·.i . Service Connections Service line connections shall be constructed and installed as shown in Part S.3 or as shown on the plans. Service lines shall enter sewer mains 45 degrees right or left of the vertical center of the sewer mains. Drop connections shall have at least a four (4") inch PVC vertical stack to within eight (8") inches of fin- ished grade on top of curb. Compact backfill around vertical stacks (drops) in eight (8") inch lifts to 95% ASTM D1557. S.203.8 MEASUREMENT A. Service Connections Service connections will be measured by the each for the various size of service connections listed in the proposal. B. Drop Service Connections Drop service connections will be measured by the each for the various size of drop service connections listed in the propsal. S.203.9 PAYMENT A. Service Connections Payment will be made at the unit price bid per each for furnishing and installing service conn~ctions, which bid price shall include all costs for the complete service connection installation includ- ing all materials, labor, equipment, excavation, wye or tee, bends, lateral pipe to the plug, plug, backfill, concrete, testing, clean up and incidentals for a complete installation. B. Drop Service Connections Payment will be made at the unit price bid per each for furnishing and installing drop service connections, which bid price shall include all costs for the complete drop service connection instal- lation including all materials, labor, equipment, excavation, wye or tee, bends, stacks, lateral or stack pipe to plug(s), plug(s), backfill, concrete, testing, clean up and incidentals for a complete installation. C. Retainage for Incomplete Work for Partial Payments 1. Service connections in place but not backfilled, compacted, tested, cleaned and/or right-of-way cleaned up, will not be considered 100% complete. The percent of connection completed will be reduced by the following percentages: a. Incomplete backfill, compaction and clean up - 6 %. b. Incomplete leakage test -2%. S.203/3 2. Monthly estimates will be paid by the each of equivalent connections properly placed, backfilled, compacted, tested, cleaned and right-of-way cleaned up. . •• l END OF SPECIFICATION S.203/4 :.r:!. SPECIFICATION NO. S.204 DETECTOR TAPE S.204.1 DESCRIPTION This section describes the manufacture and installation of detector tape to mark non-metallic piping. S.204.2 RELATED WORK SPECIFIED ELSEWHERE Part S.l -Sanitary Sewer Mains S.204.3 SUBMITTALS A. Submit manufacturer's data on materials furnished indicating compliance with the specifications. B. Submit manufacturer's "Certificate of Compliance" stating that the materials furnished comply with this specification. S.204.4 MATERIALS ··Detector tape shall be "Detectable" Terra Tape as manufactured by Griffolyn Company, Houston, Texas or approved equal. The tape shall have a warning notice indicating the use of the pipeline. S.204.5 CONSTRUCTION METHODS A. Installation 1. Install the detector tape 24" below finished grade directly above and parallel with any non-metallic sewer pipe. 2. At each manhole, bring the detector tape up to the manhole to a point approximately 24" below finished grade. Drill through the manhole and pull the detector tape through the manhole and label the loose end with a plastic marker. Grout hole with non-shrink grout or water stop material. B. Testing Provide the services of the manufacturer's representative to test for continuity. If the test indicates a discontinuity, locate and repair the damage, then retest. S.204/1 I S.204.6 MEASUREMENT Detector tape will not be considered a measured item. S.204.7 PAYMENT Cost for detector tape and installation will be included in th~ utiit price bid for installation of sewer main. END OF SPECIFICATION S.204/2 John Hall, Chairman Pam Reed, Commissioner Peggy Gamer, Commissioner Anthony Grigsby, Executive Director TEXAS NATURAL RESOURCE CONSERVATION COMMISSION Protecting Texas by Reducing and Preventing Pollution October l4, 1994 Don Garrett, P.E. Garrett ENgineering 4444 Carter Creek Pkwy Ste Bryan, Texas 77802 108 Re: Brazos Dear Mr. Garrett: We have received the design submittal included with your cover letter dated cc ~vb~r 12, 1994. The rules which regulate the design-:--i~stallat .M>n aAd te~ting•of domestic wastewater projects are found in 30 TAC, Chapter 317, of the TNRCC's rul ~ titled, "Design Criteria for Sewerage Systems". All plans and specifications submitted for TNRCC _approval must comply with these rules. Beginning on September 1, 1994, severe budget reductions required the TNRCC to eliminate most reviews of domestic wastewater project plans and specifications. At most, only a cursory review of the proposed project was performed. A technical review to determine conformity with 30 TAC Chapter 317 has NOT been performed. The proposed project is approved with the following comments and conditions: 1. An engineering report must be prepared and sealed by a Professional Engineer registered in the State of Texas. This engineering report must include all constants, graphs, equations, and calculations, which are needed to both justify the design and show full comppliance with Section 317.1 (c) of the TNRCC's rules requiring a final engineering report. Copies of this report shall be made available to the TNRCC, upon request. 2. The final version of the project plans and specifications shall include any and all information necessary to show full compliance with the -applicable requirements detailed in Chapter 317 of the TNRCC's rules. Copies of the final version of the project plans and specifications shall be made avialable to the TNRCC, upon request. RECE\VED NOV 1 0 \~ P.O. Box 13087 • Austin, Tex as 78711 -3087 • 512/239-1000 printed on recycled pape r ming soy-ba~d ink Don Garrett, P.E. Page 2 3 . Any test results necessary to show compliance with the testing require- ments of Chapter 317 shall be made available to the TNRCC, upon request. 4. The TNRCC still maintains its review authority and may uti l ize this authority at any time in the future. If plans are to undergo review, TNRCC will notify you upon receipt of the project. Also, please be aware of Section 317 .l(a)(2)(A) of the rules which states, "Approval given by the Commission is not intended to relieve the sewerage system owner or the design engineer of any liabilities or responsibilities with respect to the design, construction, or operation of the project." 5. Within 60 days of the completion of construction, an appointed engineer must notify both the Permitting Section of the TNRCC's Watershed Management Division and the appropriate Region Office of the date of completion. The engineer must also provide written certification that all construction, materials and equipment, and test results were substantial l y in accordance with the approved plans and specifications, the rules of the TNRCC and any change orders filed with the TNRCC. All notifications, certifications and change orders must include the signed and dated seal of a Profe ss ional Engineer registered in the State of Texas. 6. All plans and specifications shall conform with any other wa s te discha r ge requirements and water quality standards established by the TNRCC, as the requirements pertain to a regulated discharge . If you have any questions or if we can be of any further serv i ce, please call me at (512) 239-4554. Sincerely, ~Iv.Wk_ Thomas W. Weber . Manager, Permitting Section Watershed Management Division cc : C1ty of College St ation f NRCC, Region 9 Office , Submitted Materials Attached