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26 Development Permit 99-264 Edelweiss B C Floral Shop
- DRAINAGE COMPUTATIONS For Edelweiss Floral Shop 0.96 Acres College Station, Brazos County, T exa.s Prep ared for Robbie Sells 2204 Ferber Circle College Station, Texas 77845 Prepared b y: Garrett Engineering 4444 Carter Creek Parkway -Suite 108 Bryan , Texas 77802 Telephone : (409) 846-2688 *August, 1999 * RE·ViEWE COMPLIANCE r s 101999 COLLEGE STATION ENG~ING Garrett Ensjneering-4444 carter Creel< Par11way SUite 108 -Bryan , Tons n802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 1 Engineer's Certification I hereby certify that this report and grading plan for the drainage design of Edelweiss Floral Shop was prepared under my direct supervision in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owner thereof. DRAINAGE COMPUTATIONS for Edelweiss Floral Shop College Station, Brazos County, Texas * August, 1999 * SUMMARY The subject project is situated within the bounds of Lot 2, Block Two of Edelweiss Business Center an addition to the City of College Station, Brazos County, Texas. Said project is located on the southeast side of Rock Prairie Road approximately 210 feet southeast of the intersection of Rock Prairie Road and F.M. 2154 -Wellborn Road (See Exhibit "A" -Project Location & Vicinity Map). The property consists of a total of0 .96 acres ofland which is currently undeveloped with the exception of an existing 12 .5 foot wide concrete access drive which is constructed on the common line between Lot 1 and Lot 2, Block Two, Edelweiss Business Center. The purpose of this report is to design a stormwater detention facility to negate the impact of the proposed development on downstream properties. The proposed detention facility will be located at the southeast rear corner of Lot 2, Block Two of same Edelweiss Business Center. 0 .53 acres of the project site will free-flow from the subject site without being metered, leaving the balance of land draining to the detention pond being 0 .43 acres . The total weighted predevepment run-off coefficient for the subject site is 0 .34 and the total post-development weighted run-off coefficient is assumed to be 0.44 . The post-development weighted run-off coefficient for the total basin tributary to the detention pond is 0.43 . The total drainage basin tributary to the proposed detention pond is 0 .43 acres of land as previously stated (See Exhibit "B" -Site Plan). A storm water attenuation facility is proposed to be constructed at the rear of the subject property which will incorporate a 2' wide concrete pilot channel which slopes at a 0 .50 % grade from the back of curb on the parking are adjacent to the proposed building and will extend to the outlet of the detention pond where a 12" rectangular weir "meters" the storm water discharge at a rate less than the predevelopment discharge rate from the subject property. Said 12" weir discharges into a proposed concrete flume with a 9" curb which runs parallel to and along the toe of the downstream detention pond berm. The 9" curb has 3" wide rectangular weirs spaced at 5 foot increments along its length. The intent of the 3" wide weirs is to memic sheet drainage from the project site. The detention pond is designed to facilitate up to and include the ultimate 100-year storm event, and discharge at a rate less than the current pre-development peak discharge rates . The proposed detention facility will intercept and meter run-off from 0 .43 acres of the subject site. The run-off generated on the remaining 0 .53 acres of the subject site will be allowed to "free-flow" from the subject site in a southeasterly direction . Computations presented on page 2 present the estimated pre-development peak discharge rates generated by the 2, 5, 10 , 25 , 50 and 100-year storm events . The weighted pre-development run-off coefficient was assumed to be 0 .34 based on a total tributary drainage basin area of0.96 acres . A IO-minute time of concentration (T/c) was estimated utilizing topographic maps and field reconnaissance . The Rational Method was employed exclusiv ely throughout this document to compute the estimated peak stonn water 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, assumed to be 0 .34 in the pre-development condition, "I" is the storm intensity in inches per hour, and "A" is the area of the tributary drainage basin in acres . A 30-minute total storm event duration was utilized exclusively throughout this report. P~op 1.1 - 'J - From the computations on page 3, based on the total tributary area of 0 .96 acres, the post-development weighted run-off coefficient being assumed at 0 .44, and a minimum time of concentration of 10 minutes, the relative post-development peak discharge rates ("Q") were determined and presented in tabular form. The Rational Method was again utilized to compute the estimated peak post-development discharge rates. Computations depicted on page 3 assume no detention. Pages 14 -16 depict pre-development and post- development hydrographs for the 2, 5, 10 , 25 , 50 and 100-year storm events with no detentions considered. A comparison between the peak pre-development discharge rates and post-development discharge rates is included to aid in establishing a preliminary "target" for the volume requirements for the proposed detention facility . This preliminary estimate is computed by determining the volume generated from the difference of the pre-development and post-development hydrographs. Please note that the post- development hydrograph shown on these same graphs assumes no detention at this point in the computational process. Page 4 provides computations that determine the post-development storm water run-off which is allowed to flow from the subject site unmetered and page 5 provides computations that determine the post- development run-off that is routed through the proposed detention facility . The "free-flow" run-off computations presented on page 4 are based on a time of concentration of 10 minutes (minimum), the run- off routed through the proposed detention facility as presented on page 5 is calculated based on a time of concentration of 10 minutes. Pages 6-7 and pages 8-9 are tabulations of the pre-development hydrographs and the post-development hydrographs respectively, based on the computations performed on pages 2 & 3. The post-development hydrograph assumes no detention to facilitate direct comparison in the pre-and post-development conditions. Pages 10-11 and pages 12-13 are tabulations of the post- development hydrograph for "free-flow" storm water run-off and storm water run-off directed through the detention facility respectively. Having derived the preliminary volume requirements as presented on page 3 and "allowable peak" discharge rate as present on page 2 it is now possible to design the final detention facility and outlet control structure. Page 17 presents a tabulation and depth versus volume graph of the detention facility as proposed. The maximum pond volume necessary to provide sufficient storage for the 100-year storm condition was estimated to be approximately 943 cubic feet (page 3). The actual design for the proposed detention pond supplies 866 cubic feet at a water surface elev ation of 333 .61 (Top Of Detention Pond Berm). Page 18 presents a tabulation and rating curve for the proposed outlet control structure. A 12" wide rectangular weir functions as the outlet control structure and samewas chosen due to depth verses discharge ratio characteristics associated with the anticipated headwater depth and convenience of construction. Page 19 presents a tabulation of the relationship between discharge from the detention and the dimensionless quantity 2S/t-O. Also included is the Storage Indication Curve for the proposed detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrographs, and rating curve for the outlet structure. The storage indication curve as shown on page 19 is a graphical solution to the equation presented as follows : 2s1 (I 1 + I 2) + ( ----------------01) dt 2s2 (---------------+ 02) dt Pages 20-22, 23-25 , 26-28 , 29-31 , 32-34, and 35-37 present simulations for the 2, 5, 10, 25 , 50 and 100- year storm events. The first and second pages of each storm frequency simulation represents the tabulated data for the storm event. The third 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 the post-development "free-flow" hydrograph for each storm event. P !:l n P 1-'? - .. - Pages 38 -43 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 actually been slightly reduced from those peak pre- development discharge rates due to the incorporation of the proposed detention facility . Page 44 is a graph that sum.mates the depths , volumes, and percent of "utilized" storage volumes for the 2, 5, 10 , 25 , 50 and 100-year storm events . The construction of the proposed detention facility will minimize the effects of development on downstream property owners and will actually decrease the peak discharge rates for the range of storm events of interest within this report. P ~CTP 1-'1 Determinl! Total Pre~Development Peak Storm Watetllischarge Rates. Tributary Area ("A "): 0 .96 Acres Pervious Area : 0 .89 Acres Impervious Area : 0.07 Acres Run-Off Coefficient ("Cwt"): 0 .34 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 S-Year: 7.69 10-Year: 8 .63 2S-Year: 9.86 SO-Year: 11.1S 100-Year: 11 .64 Peak Discharge Rate ("Q"): 2-Year: 2 .09 S-Year: 2.S4 10-Year: 2 .8S 2S-Year: 3.2S SO-Year: 3 .68 100-Year: 3.84 c = 0.30 c = 0 .90 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 Garrett Engneering • 44« Carter Creek Parkway Suite 108 • Bryan, Texa s nart2 ·Telephone: (409) 846-2688 -Fax: (409) 84fl.3W4 -Pago 2 - ·Determine. Post-development Peak Storm Water Discharge (No Detention) Tribut ary Area ("A "): 0.96 Acres Perv ious Area : 0.74 Acres Impervious Area : 0.22 Acres Run -Off Coefficient ("Cwt"): 0.44 Time Of Concentration ("Tic"): 10 Minutes Hou rl y Intensity Rates ("I"): 2-Year: 6 .33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 SO-Year : 11 .15 100-Year: 11.64 c = 0.30 c = 0.90 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Peak Discharge Rate ("Q"): 2-Yea r: 2.66 Cubic Feet I Second 5-Year: 3.23 Cubic Feet I Second 10-Year: 3.63 Cubic Feet I Second 25 -Year: 4 .14 Cubic Feet I Second 50-Year: 4 .68 Cubic Feet I Second 100-Year: 4.89 Cubic Feet I Second Comparison Of Predevetopment And Post-development P:eak Dische1rge Rate$ Predevelopment Post-Development 2-Year: 2 .09 Ft 3/sec 2.66 Ft3/sec 5-Yea r: 2 .54 Ft3/sec 3 .23 Ft3/sec 10-Year: 2.85 Ft3/sec 3.63 Ft3/sec 25-Year: 3.25 Ft3/sec 4.14 Ft3/sec SO -Year: 3.68 Ft3/sec 4.68 Ft3/sec 100-Year: 3.84 Ft3/sec 4.89 Ft3/sec Preliminary Determinalion Of ·: · DetentiorrPond Volume 2-Year: 0.57 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 5-Year: 0 .69 Ft3/sec x (30 Min . x 60 Sec. I 2 ) = 10-Year: 0.78 Ft3/sec x (30 Min . x 60 Sec. I 2 ) = 25-Year: 0.89 Ft3/sec x (30 Min. x 60 Sec . I 2 ) = 50-Year: 1 . 00 Ft3/sec x (30 Min. x 60 Sec. I 2 ) = 100-Year: 1.05 Ft3/sec x (30 Min . x 60 Sec. I 2 ) = Increase 0 .57 Ft3/sec 0.69 Ft3/sec 0.78 Ft3/sec 0.89 Ft3/sec 1 . 00 Ft3/sec 1.05 Ft3/sec 512 Cubic Feet 623 Cubic Feet 699 Cubic Feet 799 Cubic Feet 903 Cubic Feet 943 Cubic Feet Time Base {Tb) = 3 00 x. Tic And Time Of Concentration !Tic) Of 10 fv1muies Gamitt Engineering-«44 Carter Creek Parl<way Suite 108-Bryan, Teus 77 802-Telej:hono: (409) 846-2688 -Fax: (409) 846-3094 -Page 3 .. . •'; I ·Determine F>ost.::e>evetof>me·r1t ····r=ree.::F1ow•·· Peak Storm WaterDischarge Tributary Area ("A"): 0 .53 Acres Pervious Area : 0 .53 Acres Impervious Area : 0.00 Acres Run-Off Coefficient ("Cwt"): 0.30 c = 0 .30 c = 0 .90 Time Of Concentration ("T/c"): 10 M inutes (Min .) Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches I Hour 5-Year: 7 .69 Inches I Hou r 10-Year: 8 .63 Inches I Hour 25-Year: 9.86 In c hes I Hour 50 -Year: 11 .15 Inches I Hour 100-Year: 11.64 Inches I Hour Peak Discharge Rate ("Q"): 2-Year: 1.01 Cubic Feet I Second 5-Year: 1.22 Cubic Feet I Second 10-Year: 1.37 Cubic Feet I Second 25-Year: 1.57 Cubic Feet I Second 50-Year: 1.77 Cubic Feet I Second 100-Year: 1.85 Cubic Feet I Second Garrett Engneering • 4444 carter Creek Parkway Suite 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 4 - Determine Post~beveiopmeraf Flow Into Detention Pond Tributary Area ("A "): 0 .43 Acres Pervious Area : 0 .21 Acres Impervious Area : 0.22 Acres Run -Off Coefficient ("Cwt"): 0.61 Time Of Concentration ("Tic"): 1 O Minutes Hour1y 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: 1.65 5-Year: 2 .01 10-Year: 2 .25 25-Year: 2.57 50-Year: 2.91 100-Year: 3.04 c = 0 .30 c = 0.90 Inches I Hour Inches I Hour Inches I Hour Inches I Hou r 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 Gam:tt Engineering · 4444 Carter Creek Parkway Suite 108 ·Bryan, T"""s 77802 • Telejlllone: (409) 84&-2688 • Fox: (409) 846-3094 • Page 5 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 0.21 0.25 0.28 0.33 0.37 0.38 2 0.42 0.51 0.57 0.65 0.74 0.77 3 0.63 0.76 0.85 0.98 1.10 1.15 4 0.84 1.02 1.14 1.30 1.47 1.54 5 1.04 1.27 1.42 1.63 1.84 1.92 6 1.25 1.52 1.71 1.95 2.21 2.30 7 1.46 1.78 1.99 2.28 2.58 2.69 8 1.67 2.03 2.28 2.60 2.94 3.07 9 1.88 2.28 2.56 2.93 3.31 3.46 10 2.09 2.54 2.85 3.25 3.68 3.84 11 1.98 2.41 2.71 3.09 3.49 3.65 12 1.88 2.28 2.56 2.93 3.31 3.46 13 1.77 2.16 2.42 2.77 3.13 3.26 14 1.67 2.03 2.28 2.60 2.94 3.07 15 1.57 1.90 2.14 2.44 2.76 2.88 16 1.46 1.78 1.99 2.28 2.58 2.69 17 1.36 1.65 1.85 2.12 2.39 2.50 18 1.25 1.52 1.71 1.95 2.21 2.30 19 1.15 1.40 1.57 1.79 2.02 2.11 20 1.04 1.27 1.42 1.63 1.84 1.92 21 0.94 1.14 1.28 1.46 1.66 1.73 22 0.84 1.02 1.14 1.30 1.47 1.54 23 0.73 0.89 1.00 1.14 1.29 1.34 24 0.63 0.76 0.85 0.98 1.10 1.15 25 0.52 0.63 0.71 0.81 0.92 0.96 26 0.42 0.51 0.57 0.65 0.74 0.77 27 0.31 0.38 0.43 0.49 0.55 0.58 28 0.21 0.25 0.28 0.33 0.37 0.38 29 0.10 0.13 0.14 0.16 0.18 0.19 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 Garrett Engineering· 4444 Carter Creek Pat1<way Suite 108 • Bryan, Texas 77802 • Telepl1one: (409) 846-2888 • Fax: (409) 846-3094 • Page 6 - 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 57 0.00 0.00 0.00 0.00 0,00 0.00 58 0.00 0.00 0.00 0.00 0.00 0.00 59 0.00 0.00 0.00 0.00 0.00 0.00 60 0.00 0.00 0.00 0.00 0.00 0.00 Garrett ErQneenng-4444 carter Creole Parl<way Suite 108 ·Bryan, Texas 77802-Telephone: (409) 846-2688 -FilX'. (409) 846-309-4 -Page 7 • 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 0.27 0.32 0.36 0.41 0.47 0.49 2 0.53 0.65 0.73 0.83 0.94 0.98 3 0.80 0.97 1.09 1.24 1.40 1.47 4 1.06 1.29 1.45 1.66 1.87 1.96 5 1.33 1.62 1.81 2.07 2.34 2.44 6 1.59 1.94 2.18 2.49 2.81 2.93 7 1.86 2.26 2.54 2.90 3.28 3.42 8 2.13 2.58 2.90 3.31 3.75 3.91 9 2.39 2.91 3.26 3.73 4.21 4.40 10 2.66 3.23 3.63 4.14 4.68 4.89 11 2.52 3.07 3.45 3.93 4.45 4.64 12 2.39 2.91 3.26 3.73 4.21 4.40 13 2.26 2.75 3.08 3.52 3.98 4.16 14 2.13 2.58 2.90 3.31 3.75 3.91 15 1.99 2.42 2.72 3.11 3.51 3.67 16 1.86 2.26 2.54 2.90 3.28 3.42 17 1.73 2.10 2.36 2.69 3.04 3.18 18 1.59 1.94 2.18 2.49 2.81 2.93 19 1.46 1.78 1.99 2.28 2.58 2.69 20 1.33 1.62 1.81 2.07 2.34 2.44 21 1.20 1.45 1.63 1.86 2.11 2.20 22 1.06 1.29 1.45 1.66 1.87 1.96 23 0.93 1.13 1.27 1.45 1.64 1.71 24 0.80 0.97 1.09 1.24 1.40 1.47 25 0.66 0.81 0.91 1.04 1.17 1.22 26 0.53 0.65 0.73 0.83 0.94 0.98 27 0.40 0.48 0.54 0.62 0.70 0.73 28 0.27 0.32 0.36 0.41 0.47 0.49 29 0.13 0.16 0.18 0.21 0.23 0.24 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 Garrett Engineering· 4444 Carter Creek Par1<way SUito 108 -Bryan, Tex"' 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 8 - 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 57 0.00 0.00 0.00 0.00 0.00 0.00 58 0.00 0.00 0.00 0.00 0.00 0.00 59 0.00 0.00 0.00 0.00 0.00 0.00 60 0.00 0.00 0.00 0.00 0.00 0.00 Garrett Engineering· 44+4 Caner Creek Parkway Suite 108 -B<yan, Texas 77802-Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 9 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 0.10 0.12 0.14 0.16 0.18 0.19 2 0.20 0.24 0.27 0.31 0.35 0.37 3 0.30 0.37 0.41 0.47 0.53 0.56 4 0.40 0.49 0.55 0.63 0.71 0.74 5 0.50 0.61 0.69 0.78 0.89 0.93 6 0.60 0.73 0.82 0.94 1.06 1.11 7 0.70 0.86 0.96 1.10 1.24 1.30 8 0.80 0.98 1.10 1.25 1.42 1.48 9 0.91 1.10 1.24 1.41 1.60 1.67 10 1.01 1.22 1.37 1.57 1.77 1.85 11 0.96 1.16 1.30 1.49 1.68 1.76 12 0.91 1.10 1.24 1.41 1.60 1.67 13 0.86 1.04 1.17 1.33 1.51 1.57 14 0.80 0,98 1.10 1.25 1.42 1.48 15 0.75 0.92 1.03 1.18 1.33 1.39 16 0.70 0.86 0.96 1.10 1.24 1.30 17 0.65 0.80 0.89 1.02 1.15 1.20 18 0.60 0.73 0.82 0.94 1.06 1.11 19 0.55 0.67 0.76 0.86 0.97 1.02 20 0.50 0.61 0.69 0.78 0.89 0.93 21 0.45 0.55 0.62 0.71 0.80 0.83 22 0.40 0.49 0.55 0.63 0.71 0.74 23 0.35 0.43 0.48 0.55 0.62 0.65 24 0.30 0.37 0.41 0.47 0.53 0.56 25 0.25 0.31 0.34 0.39 0.44 0.46 26 0.20 0.24 0.27 0.31 0.35 0.37 27 0.15 0.18 0.21 0.24 0.27 0.28 28 0.10 0.12 0.14 0.16 0.18 0.19 29 0.05 0.06 0.07 0.08 0.09 0.09 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 Garrett Engineering· 44« Cart..-Creek Parl<way Suite 108-Bryan, Texas 77802-Telephone: (409) 84&-2888 -Fax: (409) 84&-3094 -Page 10 - 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 57 0.00 0.00 0.00 0.00 0.00 0.00 58 0.00 0.00 0.00 0.00 0.00 0.00 59 0.00 0.00 0.00 0.00 0.00 0.00 60 0.00 0.00 0.00 0.00 0.00 0.00 Gan-ett Engineering-4444 Carter Creek Par1<way Suite 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 11 - Post-Development Flow Routed Through Detention Pond Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year SO-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 Q_QQ 0.00 0.00 0.00 0.00 0.00 1 0.17 0.20 0.23 0.26 0.29 0.30 2 0.33 0.40 0.45 0.51 0.58 0.61 3 0.50 0.60 0.68 0.77 0.87 0.91 4 0.66 0.80 0.90 1.03 1.16 1.22 5 0.83 1.00 1.13 1.29 1.45 1.52 6 0.99 1.20 1.35 1.54 1.75 1.82 7 1.16 1.41 1.58 1.80 2.04 2.13 8 1.32 1.61 1.80 2.06 2.33 2.43 9 1.49 1.81 2.03 2.32 2.62 2.73 10 1.65 2.01 2.25 2.57 2.91 3.04 11 1.57 1.91 2.14 2.45 2.76 2.89 12 1.49 1.81 2.03 2.32 2.62 2.73 13 1.40 1.71 1.92 2.19 2.47 2.58 14 1.32 1.61 1.80 2.06 2.33 2.43 15 1.24 1.51 1.69 1.93 2.18 2.28 16 1.16 1.41 1.58 1.80 2.04 2.13 17 1.07 1.31 1.46 1.67 1.89 1.97 18 0.99 1.20 1.35 1.54 1.75 1.82 19 0.91 1.10 1.24 1.42 1.60 1.67 20 0.83 1.00 1.13 1.29 1.45 1.52 21 0.74 0.90 1.01 1.16 1.31 1.37 22 0.66 0.80 0.90 1.03 1.16 1.22 23 0.58 0.70 0.79 0.90 1.02 1.06 24 0.50 0.60 0.68 0.77 0.87 0.91 25 0.41 0.50 0.56 0.64 0.73 0.76 26 0.33 0.40 0.45 0.51 0.58 0.61 27 0.25 0.30 0.34 0.39 0.44 0.46 28 0.17 0.20 0.23 0.26 0.29 0.30 29 0.08 0.10 0.11 0.13 0.15 0.15 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 Garrott Engineering-4444 Carter Creek Par1<way SUie 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 12 ,.. 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 57 0.00 0.00 0.00 0.00 0.00 0.00 58 0.00 0.00 0.00 0.00 0.00 0.00 59 0.00 0.00 0.00 0.00 0.00 0.00 60 0.00 0.00 0.00 0.00 0.00 0.00 Garrett Engineering-4444 Carter Creek Par1<way Suite 108-Bryan, Tens 77802-Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Pago 13 ... • 3 .00 ~ Cl) 2 .50 a.. -Cl) Cl) 2 .00 LL u- ·-'1:1 .Q c :J 0 1 .50 0 I.) -Cl) Cl) rn Cl 1 .00 ~ C'IS .t::. I.) .!!? 0.50 c 0 .00 0 ~ Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 2-Year Storm Event 10 20 30 40 50 Time (Minutes) -----Pre-Development Hydrograph ---Total Post-Development Hydrograph Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 5-Year Storm Event ~ 3.00 -----1-1-------+------+-----+-------+-----j -Cl) if 2 .50 u-:c ~ 2.00---#--1"--l--"-~----+------+-----+-------+-----j :J 0 0 I.) -Cl) 1 .50 ---+-.---J-------"oc--1"....-----+-----+-------+-----j Cl> rn Cl ; 1.oo...--++---1------+_,,,,,__.. __ -+-----+------1----....., .t::. I.) 5 0.50+-'4~---+------t-----''&---l-----+-----1-----~ O .OOY--------+------~t--------~-------:.------~-e-~~~-= 0 10 20 ----Pre-Development Hydrograph 30 40 50 Time (Minutes) ---Post-Development Outflow Hydrograph Without Detention Garrett Engineering · 4444 Ca rter Creek Parkway S<ite 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 14 60 60 ... Cl.I Q. Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 10-Year Storm Event 4 .00 ------~---~----~--------~----~ 3.50------#~-----+-----+-----;--------j-----j ~ 3 .00 ----#--1--'l<-----+------+-----+-------t------t Cl.I u. U -2 .50 ----#-~Y--'...,_---"---+------+-----+-------t------t :c -g a 8 2.00-----4'-<--+------.-+------+------+------;-------; -Cl.I ~ (/) 1 .50 -----1---------"d--'1<-----+------t--------j-----j ... "' "fi 1 .00 .!!? c 0.50 +-Jl'-----+-----+---~--1-----1-----f------l ... Cl.I Q. .. Cl.I 0.00 Y-----+---....-ji------------11'----..-----a 0 10 20 30 40 50 Time (Minutes) ----·--Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detent ion Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 25-Year Storm Event 60 4 .50 ----~----~---~----~--------~ 4 .00 ----------+-------l-----+-----1--------l if 3 .oo----+-+-~-~---+-----+-----+------1-----l u-:c -g 2.50---#---f'--l------'T-~--+-----+-----+------1-----l :J 0 0 u -Cl.I 2.00 __ _,__,~----+---~,,,__-----+------+-----<-------< Cl.I (/) Cl ... "' .r; u en Q 1 .50 -----J'4------il----------+'....._.~---+-----+------1-----l 1 .00 -----+-----+-~~----1-----+-----1--------l 0 .50 ...,c___ __ -+-----!---~~-+------J.----+----__j 0 .00 Y-----..---~...-----.'-----:.----.:-----: 0 10 20 ---Pre-Development Hydrograph 30 40 50 Time (Minutes) ---Post-Development Outflow Hyd rograph Without Detent ion Garrett Engineering· 4444 Carter Creek Parkway Suite 108 ·Bryan , Texas 77802 ·Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 15 60 5.00 ... 4.50 Cl) ~ 4 .00 Cl) if 3 .50 .!: :c 3.00 ..c c: c3 8 2.50 -Cl) Cl) en 2.00 Cl ... C'CJ ..c: u .!!? 1 .50 1 .00 c 0 .50 0 .00 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 50-Year Storm Event "' I ' I ' ' I I ""'' I I "'' I I " ' ~ I I '[',, // "" JI "'-\.. l "· 0 10 20 30 40 50 Time (Minutes) ··---Pre-Development Hydrograph ---Post-Development Outflow Hydrograph Without Detention 5 .00 ~ 4 .50 a. -4.00 Cl) if 3.50 :a :c 3.00 ::J c: 0 8 2 .50 -Cl) Cl) en 2.00 Cl ; 1 .50 ..c: ~ 1.00 Ci 0.50 0.00 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 100-Year Storm Event '~ I '\. I I !'-. '\. I I "\. '\. I I ,, '\. I I "-, \. I I "'\. II "" // ~ ' " 0 10 20 30 40 50 Time (Minutes) -----·---Pre-Development Hydrograph Post-Development Outflow Hydrograph W ithout Detention Garrett Engneering-4444 Carter creek Parkway Suite 108 • Btyan, Texas 77802 -Tele!>lione : (409) 84&-2688 -Fax: (409) 84&-3094 -Page 16 60 60 Detention Pond De th Vs. Volume 0 .90 0 .80 0 .70 0.60 -'$ 0.50 !:!:. .c -Q. g 0.40 0 .30 0 .20 Elevation 332.77 332 .85 332.95 333 .00 333.30 333.61 y / 0 .10 0 .00 Depth (Feet) 0 .00 0 .08 0 .18 0 .23 0 .53 0 .84 Volume (Ft3) 0 82 186 237 546 866 Detention Pond Depth Vs. Volume / / , / , /~ /' / / , 0 100 200 300 400 500 600 700 800 Detention Pond Volume (Cubic Feet) Garrett Engneering-4444 Carter Creek Partcway SUite 108 -Bryan . Tegs 77802 -Telei:t>one : (409) 846-2688 -Fax: (409) 846-3094 -Page 17 900 Rating Curve For Outlet Controt Structure De th Vs ~ Volume 0.90 0.80 0.70 0.60 --g: 0 .50 !:!:. .r:. -g. 0.40 c 0.30 0.20 0.10 0.00 0.00 Elevation 332 .77 332 .85 332 .95 333 .00 333 .30 333 .61 Depth (Feet) 0 .00 0.08 0 .18 0.23 0.53 0.84 Discharge Ft3/Sec 0 .00 0.07 0.23 0.33 1.16 2 .31 Rating Curve For Outlet Control Structure Depth Vs. Volume 0.50 1.00 1.50 2.00 Discharge (Cubic Feet Per Second) Garrett Engneering· 4444 Carter Creek Pall<way Suite 108. Bryan, Texas 77802 ·Telephone : (409) 846-2688 -Fax: (409) 846-3094 -Pago 18 2 .50 !storage Indication Curve -"C c 0 I.) Cl) (/) ... Cl) D.. ... Cl) Cl) u. I.) :a :::I 0 2 .50 2.00 1.50 -; 1.00 Ol ... ns .c I.) Cl) c 0 .50 0.00 Depth (Feet) 0 .00 0 .08 0 .18 0 .23 0.53 0.84 0.00 5.00 Storage Discharge 2s/t 2s/t+O (Ft3) (Ft3/Sec) (Ft3/Sec) (Ft3/Sec) 0 0.00 0 .00 0 .00 82 0.07 2 .73 2 .80 186 0.23 6 .20 6 .43 237 0 .33 7.90 8 .23 546 1.16 18.20 19 .36 866 2 .31 28.87 31.18 Storage Indication Curve 10 .00 15.00 20 .00 25.00 30 .00 2s/t+O (Cubic Feet Per Second) Garrett Engineering-4444 Carter Creek Part<way Suite 108 -Bryan, Texas 77802 -Telephone: (409) 846-2888 ·Fax: (409) 846-3094 • Page 19 35.00 Inflow I Outflow Simulation 2-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.17 0.17 0.16 0.17 0.00 0.00 332.77 2 0.33 0.50 0.62 0.65 0.02 0.02 332.79 3 0.50 0.83 1.37 1.45 0.04 0.04 332.81 4 0.66 1.16 2.40 2.53 0.06 0.07 332.84 5 0.83 1.49 3.65 3.89 0.12 0.11 332.88 6 0.99 1.82 5.09 5.47 0.19 0.15 332.92 7 1.16 2.15 6.69 7.24 0.28 0.20 332.97 8 1.32 2.48 8.37 9.17 0.40 0.26 333.03 9 1.49 2.81 10.08 11.17 0.55 0.31 333.08 10 1.65 3.14 11.81 13.21 0.70 0.36 333.13 11 1.57 3.22 13.36 15.03 0.84 0.41 333.18 12 1.49 3.05 14.53 16.41 0.94 0.45 333.22 13 1.40 2.89 15.39 17.42 1.02 0.48 333.25 14 1.32 2.72 15.98 18.11 1.07 0.50 333.27 15 1.24 2.56 16.34 18.54 1.10 0.51 333.28 16 1.16 2.39 16.51 18.74 1.11 0.51 333.28 17 1.07 2.23 16.51 18.74 1.11 0.51 333.28 18 0.99 2.06 16.37 18.57 1.10 0.51 333.28 19 0.91 1.90 16.11 18.27 1.08 0.50 333.27 20 0.83 1.73 15.75 17.85 1.05 0.49 333.26 21 0.74 1.57 15.31 17.32 1.01 0.48 333.25 22 0.66 1.40 14.78 16.71 0.96 0.46 333.23 23 0.58 1.24 14.20 16.02 0.91 0.44 333.21 24 0.50 1.07 13.56 15.27 0.86 0.42 333.19 25 0.41 0.91 12.88 14.47 0.80 0.40 333.17 26 0.33 0.74 12.16 13.62 0.73 0.38 333.15 27 0.25 0.58 11.40 12.74 0.67 0.35 333.12 28 0.17 0.41 10.62 11.82 0.60 0.33 333.10 29 0.08 0.25 9.82 10.87 0.53 0.30 333.07 30 0.00 0.08 8.99 9.90 0.45 0.27 333.04 31 0.00 0.00 8.22 8.99 0.39 0.25 333.02 32 0.00 0.00 7.56 8.22 0.33 0.23 333.00 33 0.00 0.00 6.97 7.56 0.29 0.21 332.98 34 0.00 0.00 6.45 6.97 0.26 0.20 332.97 35 0.00 0.00 5.99 6.45 0.23 0.18 332.95 36 0.00 0.00 5.57 5.99 0.21 0.17 332.94 37 0.00 0.00 5.18 5.57 0.19 0.16 332.93 38 0.00 0.00 4.83 5.18 0.18 0.15 332.92 39 0.00 0.00 4.52 4.83 0.16 0.14 332.91 40 0.00 0.00 4.22 4.52 0.15 0.13 332.90 41 0.00 0.00 3.96 4.22 0.13 0.12 332.89 42 0.00 0.00 3.72 3.96 0.12 0.11 332.88 43 0.00 0.00 3.50 3.72 0.11 0.11 332.88 44 0.00 0.00 3.30 3.50 0.10 0.10 332.87 45 0.00 0.00 3.11 3.30 0.09 0.09 332.86 Garrett Ensjneering • 4444 Carter Creek Parl<way Suite 108-Bryan. Tens 77802-Tele~: (409) 846-2688 • Fax: (409) 846-3094 -Page 20 ... 46 0.00 0.00 2.94 3.11 0.08 0.09 332.86 47 0.00 0.00 2.79 2.94 0.08 0.08 332.85 48 0.00 0.00 2.65 2.79 0.07 0.08 332.85 49 0.00 0.00 2.52 2.65 0.07 0.08 332.85 50 o_oo 0.00 2.39 2.52 0_06 0.07 332.84 51 0.00 0.00 2.27 2.39 0.06 0.07 332.84 52 0.00 0.00 2.16 2.27 0.06 0.06 332.83 53 0.00 0.00 2.05 2.16 0.05 0.06 332.83 54 0.00 0.00 1.95 2.05 0.05 0.06 332.83 55 0.00 0.00 1.85 1.95 0.05 0.06 332.83 56 0.00 0.00 1.76 1.85 0.05 0.05 332.82 57 0.00 0.00 1.67 1.76 0.04 0.05 332.82 58 0.00 0.00 1.59 1.67 0.04 0.05 332.82 59 0.00 0.00 1.51 1.59 0.04 0.05 332.82 60 0.00 0.00 1.43 1.51 0.04 0.04 332.81 Garrett Engineering-4444 Carter Creek Parkway Suite 108-Biyan, Texas 77802-Telephone: (409) 846-2888 - Fax: (409) 846-3094 -Page 21 "' -"C c: 0 (,,) 4> CJ) '-4> a.. .... 4> 4> u. (,,) :.0 :::l ~ ~ 0 s :::l 0 Inflow/Outflow Simulation 2-Year Storm Event 3.00 ' 2.50 f 2 .00 I • I I I • I 1 .50 ' ! I ,: / f 1.00 0 .50 I 1 • J . .' ' I 1/ . I 0.00 0 10 ----Pre- Developrnent Hydrograph ' ' ' \ ' \ \ \ 20 30 40 Time (Minutes) - - -• Post- Developrnent Outflow Hydrograph Without Detention ---•Post- Developrnent Outflow With Detention 50 --- - -Post- Developrnent "Free-Flow" Garrett Engneering -4444 Carter Creek Parkway &lite 108 -Bryan , Texas 77802 -Telepllone: (409) 846-2688 -Fax: (409) 846-3094 • Page 22 60 Inflow I Outflow Simulation 5-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.20 0.20 0.19 0.20 0.01 0.01 332.78 2 0.40 0.60 0.75 0.79 0.02 0.02 332.79 3 0.60 1.00 1.67 1.76 0.04 0.05 332.82 4 0.80 1.41 2.91 3.08 0.08 0.09 332.86 5 1.00 1.81 4.41 4.72 0.15 0.13 332.90 6 1.20 2.21 6.14 6.62 0.24 0.19 332.96 7 1.41 2.61 8.01 8.75 0.37 0.24 333.01 8 1.61 3.01 9.95 11.02 0.54 0.31 333.08 9 1.81 3.41 11.93 13.36 0.71 0.37 333.14 10 2.01 3.81 13.97 15.75 0.89 0.43 333.20 11 1.91 3.92 15.78 17.88 1.05 0.49 333.26 12 1.81 3.71 17.15 19.50 1.17 0.53 333.30 13 1.71 3.51 18.09 20.66 1.29 0.56 333.33 14 1.61 3.31 18.69 21.40 1.36 0.58 333.35 15 1.51 3.11 19.00 21.80 1.40 0.59 333.36 16 1.41 2.91 19.10 21.91 1.41 0.60 333.37 17 1.31 2.71 19.01 21.81 1.40 0.59 333.36 18 1.20 2.51 18.78 21.52 1.37 0.59 333.36 19 1.10 2.31 18.43 21.09 1.33 0.58 333.35 20 1.00 2.11 17.99 20.54 1.27 0.56 333.33 21 0.90 1.91 17.47 19.90 1.21 0.54 333.31 22 0.80 1.71 16.89 19.18 1.15 0.53 333.30 23 0.70 1.51 16.22 18.39 1.09 0.50 333.27 24 0.60 1.31 15.48 17.52 1.02 0.48 333.25 25 0.50 1.10 14.68 16.58 0.95 0.46 333.23 26 0.40 0.90 13.82 15.58 0.88 0.43 333.20 27 0.30 0.70 12.93 14.53 0.80 0.40 333.17 28 0.20 0.50 11.99 13.43 0.72 0.37 333.14 29 0.10 0.30 11.03 12.29 0.63 0.34 333.11 30 0.00 0.10 10.04 11.13 0.55 0.31 333.08 31 0.00 0.00 9.11 10.04 0.46 0.28 333.05 32 0.00 0.00 8.32 9.11 0.40 0.25 333.02 33 0.00 0.00 7.64 8.32 0.34 0.23 333.00 34 0.00 0.00 7.05 7.64 0.30 0.21 332.98 35 0.00 0.00 6.52 7.05 0.26 0.20 332.97 36 0.00 0.00 6.05 6.52 0.23 0.18 332.95 37 0.00 0.00 5.62 6.05 0.21 0.17 332.94 38 0.00 0.00 5.23 5.62 0.19 0.16 332.93 39 0.00 0.00 4.88 5.23 0.18 0.15 332.92 40 0.00 0.00 4.56 4.88 0.16 0.14 332.91 41 0.00 0.00 4.26 4.56 0.15 0.13 332.90 42 0.00 0.00 3.99 4.26 0.13 0.12 332.89 43 0.00 0.00 3.75 3.99 0.12 0.11 332.88 44 0.00 0.00 3.52 3.75 0.11 0.11 332.88 45 0.00 0.00 3.32 3.52 0.10 0.10 332.87 Garrett Ens;jneering-4444 Carter Creek Par1<way Su~e 108 -Bryan, Tens 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 23 ... 46 0.00 0.00 3.14 3.32 0.09 0.09 332.86 47 0.00 0.00 2.97 3.14 0.08 0.09 332.86 48 0.00 0.00 2.81 2.97 0.08 0.08 332.85 49 0.00 0.00 2.67 2.81 0.07 0.08 332.85 50 0.00 0.00 2.54 2.67 0.07 0.08 332.85 51 0.00 0.00 2.41 2.54 0.06 0.07 332.84 52 0.00 0.00 2.29 2.41 0.06 0.07 332.84 53 0.00 0.00 2.18 2.29 0.06 0.07 332.84 54 0.00 0.00 2.07 2.18 0.05 0.06 332.83 55 0.00 0.00 1.96 2.07 0.05 0.06 332.83 56 0.00 0.00 1.87 1.96 0.05 0.06 332.83 57 0.00 0.00 1.77 1.87 0.05 0.05 332.82 58 0.00 0.00 1.68 1.77 0.04 0.05 332.82 59 0.00 0.00 1.60 1.68 0.04 0.05 332.82 60 0.00 0.00 1.52 1.60 0.04 0.05 332.82 Garrett Engineering· 4444 Corter Creek Parl<way Suite 108 • Bryan, Texas 77802 ·Telephone: (409) 846-2688 • Fax: (409) 846-~ • Page 24 ... -"O c 0 u Q) "' ... Q) c.. -Q) Q) LL u :c ~ ~ ~ 0 5 ~ 0 Inflow/Outflow Simulation 5-Year Storm Event 3 .50 3.00 2 .50 2 .00 1.50 1.00 0 .50 0 .00 0 I I ' J \ .: I I :1 i • I J f I 10 ----Pre- Development Hydrograph \ ' l ' \ \ ·. \ ' 20 30 40 Time (Minutes) Post- Development Outflow Hydrograp h Without Detention ---•Post- Development Outflow With Detention 50 ---· --· Post- Development "Free-Flow" Garrett EnOneering· 4444 Carter Creek Parl<way Suite 108-Bryan, Texas 77802-Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 25 60 Inflow I Outflow Simulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.23 0.23 0.21 0.23 0.01 0.01 332.78 2 0.45 0.68 0.85 0.89 0.02 0.03 332.80 3 0.68 1.13 1.87 1.97 0.05 0.06 332.83 4 0.90 1.58 3.25 3.45 0.10 0.10 332.87 5 1.13 2.03 4.92 5.28 0.18 0.15 332.92 6 1.35 2.48 6.83 7.40 0.28 0.21 332.98 7 1.58 2.93 8.88 9.76 0.44 0.27 333.04 8 1.80 3.38 11.00 12.26 0.63 0.34 333.11 9 2.03 3.83 13.18 14.83 0.82 0.41 333.18 10 2.25 4.28 15.43 17.46 1.02 0.48 333.25 11 2.14 4.39 17.41 19.82 1.20 0.54 333.31 12 2.03 4.17 18.83 21.58 1.38 0.59 333.36 13 1.92 3.94 19.79 22.77 1.49 0.62 333.39 14 1.80 3.72 20.38 23.51 1.56 0.64 333.41 15 1.69 3.49 20.67 23.87 1.60 0.65 333.42 16 1.58 3.27 20.73 23.94 1.61 0.65 333.42 17 1.46 3.04 20.59 23.77 1.59 0.65 333.42 18 1.35 2.82 20.30 23.41 1.55 0.64 333.41 19 1.24 2.59 19.89 22.89 1.50 0.62 333.39 20 1.13 2.37 19.37 22.25 1.44 0.61 333.38 21 1.01 2.14 18.77 21.51 1.37 0.59 333.36 22 0.90 1.92 18.11 20.69 1.29 0.56 333.33 23 0.79 1.69 17.39 19.80 1.20 0.54 333.31 24 0.68 1.46 16.61 18.86 1.12 0.52 333.29 25 0.56 1.24 15.76 17.85 1.05 0.49 333.26 26 0.45 1.01 14.84 16.77 0.97 0.46 333.23 27 0.34 0.79 13.86 15.63 0.88 0.43 333.20 28 0.23 0.56 12.84 14.43 0.79 0.40 333.17 29 0.11 0.34 11.78 13.18 0.70 0.36 333.13 30 0.00 0.11 10.69 11.89 0.60 0.33 333.10 31 0.00 0.00 9.66 10.69 0.51 0.30 333.07 32 0.00 0.00 8.79 9.66 0.44 0.27 333.04 33 0.00 0.00 8.04 8.79 0.37 0.25 333.02 34 0.00 0.00 7.41 8.04 0.32 0.22 332.99 35 0.00 0.00 6.84 7.41 0.28 0.21 332.98 36 0.00 0.00 6.33 6.84 0.25 0.19 332.96 37 0.00 0.00 5.88 6.33 0.23 0.18 332.95 38 0.00 0.00 5.47 5.88 0.21 0.16 332.93 39 0.00 0.00 5.09 5.47 0.19 0.15 332.92 40 0.00 0.00 4.75 5.09 0.17 0.14 332.91 41 0.00 0.00 4.44 4.75 0.16 0.13 332.90 42 0.00 0.00 4.16 4.44 0.14 0.13 332.90 43 0.00 0.00 3.90 4.16 0.13 0.12 332.89 44 0.00 0.00 3.66 3.90 0.12 0.11 332.88 Garrett Ef9neering • 4444 Carter Creek Parkway Suite 108 • Bryan, Texas 77802 ·Telephone: (409) 846-2688 • Fax: (409) 846-3094 -Page 26 I'll 45 0.00 0.00 3.44 3.66 0.11 0.10 332.87 46 0.00 0.00 3.25 3.44 0.10 0.10 332.87 47 0.00 0.00 3.07 3.25 0.09 0.09 332.86 48 0.00 0.00 2.90 3.07 0.08 0.09 332.86 49 0.00 0.00 2.76 2.90 0.07 0.08 332.85 50 0.00 0.00 2.62 2.76 0.07 0.08 332.85 51 0.00 0.00 2.49 2.62 0.07 0.07 332.84 52 0.00 0.00 2.36 2.49 0.06 0.07 332.84 53 0.00 0.00 2.25 2.36 0.06 0.07 332.84 54 0.00 0.00 2.13 2.25 0.06 0.06 332.83 55 0.00 0.00 2.03 2.13 0.05 0.06 332.83 56 0.00 0.00 1.93 2.03 0.05 0.06 332.83 57 0.00 0.00 1.83 1.93 0.05 0.05 332.82 58 0.00 0.00 1.74 1.83 0.05 0.05 332.82 59 0.00 0.00 1.65 1.74 0.04 0.05 332.82 60 0.00 0.00 1.57 1.65 0.04 0.05 332.82 Garrett Engineering-4444 Carter Creek Parkway &Jite 108 -Bryan, Texas 77802-Telephono: (409) 846-2688 -Fax: (409) 846-3094 -Page 27 Inflow/Outflow Simulation 10-Year Storm Event -"C c: 0 4.00 3 .50 3.00 ~ 2 .50 "' ... Cl) a. -Cl) if 2.00 u :c ::I ~ ~ 1.50 5 ::I 0 1 .00 0.50 0.00 0 I :'/ I I J f ' I i I f r/ l •: , . \ 10 ----Pre- Development Hydrograph ' \ \ \ \ 20 30 40 50 Time (Minutes) • Post- Development Outflow Hydrograph Without Detention ----Post----- - - -Post- Development Development Outflow With "Free-Flow'' Detention G•~ Engneering· 4444 Carter Creek Parkway Suite 108 ·Bryan, T"""s 77802 ·Telephone: (409) 846-2688 -Fox: (409) 846-3094 • PoJlO 28 60 Inflow I Outflow Simulation 25-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.26 0.26 0.24 0.26 0.01 0.01 332.78 2 0.51 0.77 0.97 1.02 0.03 0.03 332.80 3 0.77 1.29 2.14 2.25 0.06 0.06 332.83 4 1.03 1.80 3.70 3.94 0.12 0.11 332.88 5 1.29 2.32 5.59 6.02 0.21 0.17 332.94 6 1.54 2.83 7.74 8.43 0.34 0.24 333.01 7 1.80 3.35 10.00 11.08 0.54 0.31 333.08 8 2.06 3.86 12.36 13.86 0.75 0.38 333.15 9 2.32 4.38 14.81 16.73 0.96 0.46 333.23 10 2.57 4.89 17.31 19.70 1.19 0.54 333.31 11 2.45 5.02 19.43 22.33 1.45 0.61 333.38 12 2.32 4.76 20.93 24.19 1.63 0.66 333.43 13 2.19 4.50 21.93 25.44 1.75 0.69 333.46 14 2.06 4.25 22.53 26.18 1.82 0.71 333.48 15 1.93 3.99 22.81 26.52 1.86 0.72 333.49 16 1.80 3.73 22.82 26.54 1.86 0.72 333.49 17 1.67 3.47 22.63 26.30 1.84 0.71 333.48 18 1.54 3.22 22.26 25.84 1.79 0.70 333.47 19 1.42 2.96 21.76 25.22 1.73 0.68 333.45 20 1.29 2.70 21.15 24.46 1.66 0.66 333.43 21 1.16 2.45 20.45 23.60 1.57 0.64 333.41 22 1.03 2.19 19.68 22.64 1.48 0.62 333.39 23 0.90 1.93 18.85 21.61 1.38 0.59 333.36 24 0.77 1.67 17.98 20.53 1.27 0.56 333.33 25 0.64 1.42 17.07 19.39 1.16 0.53 333.30 26 0.51 1.16 16.08 18.23 1.08 0.50 333.27 27 0.39 0.90 15.01 16.98 0.98 0.47 333.24 28 0.26 0.64 13.89 15.66 0.88 0.43 333.20 29 0.13 0.39 12.71 14.27 0.78 0.39 333.16 30 0.00 0.13 11.49 12.84 0.67 0.35 333.12 31 0.00 0.00 10.35 11.49 0.57 0.32 333.09 32 0.00 0.00 9.37 10.35 0.49 0.29 333.06 33 0.00 0.00 8.54 9.37 0.42 0.26 333.03 34 0.00 0.00 7.83 8.54 0.35 0.24 333.01 35 0.00 0.00 7.22 7.83 0.31 0.22 332.99 36 0.00 0.00 6.67 7.22 0.27 0.20 332.97 37 0.00 0.00 6.18 6.67 0.24 0.19 332.96 38 0.00 0.00 5.75 6.18 0.22 0.17 332.94 39 0.00 0.00 5.35 5.75 0.20 0.16 332.93 40 0.00 0.00 4.98 5.35 0.18 0.15 332.92 41 0.00 0.00 4.65 4.98 0.17 0.14 332.91 42 0.00 0.00 4.35 4.65 0.15 0.13 332.90 43 0.00 0.00 4.07 4.35 0.14 0.12 332.89 44 0.00 0.00 3.82 4.07 0.13 0.11 332.88 45 0.00 0.00 3.59 3.82 0.11 0.11 332.88 Garrett Engineering· 4444 Carter Creek Parkway Suite 108 • Bryan, Texas 77802 ·Telephone: (409) 846-2688 • Fax: (409) 846-3094 • Page 29 - 46 0.00 0.00 3.38 3.59 0.10 0.10 332.87 47 0.00 0.00 3.19 3.38 0.10 0.10 332.87 48 0.00 0.00 3.01 3.19 0.09 0.09 332.86 49 0.00 0.00 2.86 3.01 0.08 0.09 332.86 50 0.00 0.00 2.71 2.86 0.07 0.08 332.85 51 0.00 0.00 2.58 2.71 0.07 0.08 332.85 52 0.00 0.00 2.45 2.58 0.06 0.07 332.84 53 0.00 0.00 2.33 2.45 0.06 0.07 332.84 54 0.00 0.00 2.21 2.33 0.06 0.07 332.84 55 0.00 0.00 2.10 2.21 0.06 0.06 332.83 56 0.00 0.00 1.99 2.10 0.05 0.06 332.83 57 0.00 0.00 1.89 1.99 0.05 0.06 332.83 58 0.00 0.00 1.80 1.89 0.05 0.05 332.82 59 0.00 0.00 1.71 1.80 0.04 0.05 332.82 60 0.00 0.00 1.62 1.71 0.04 0.05 332.82 Garrett En!jneering-4444 Carter Creek Par1<way Suite 108-Btyan, Texas 77&J2 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 30 ... -"C c: 0 (,,) Q,I rn .... Q,I a.. -Q,I Q,I u. (,,) :s :J ~ 3: 0 5 :J 0 Inflow/Outflow Simulation 25-Year Storm Event 4 .50 4.00 l I ~ 3.50 ' I I f 3 .00 .:; J i 2.50 I ! 2 .00 • j , I I 1 .50 :/ ,:; 1.00 ·I 0 .50 0 .00 0 10 ---·-·--Pre- Development Hydrograph \ ' \ l ' l • \ '\ . \ 20 30 40 50 Time (Minutes) • Post- Development Outflow Hydrograph Without Detention ----Post-• • ----• Post- Development Development Outflow With "Free-Flow" Detention Garrett Engineering-4444 Carter Creek Parl<way Suite 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 31 60 Inflow I Outflow Simulation SO-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.29 0.29 0.28 0.29 0.01 0.01 332.78 2 0.58 0.87 1.09 1.15 0.03 0.03 332.80 3 0.87 1.45 2.42 2.55 0.06 0.07 332.84 4 1.16 2.04 4.17 4.46 0.14 0.13 332.90 5 1.45 2.62 6.29 6.79 0.25 0.19 332.96 6 1.75 3.20 8.64 9.49 0.42 0.26 333.03 7 2.04 3.78 11.14 12.42 0.64 0.34 333.11 8 2.33 4.36 13.76 15.50 0.87 0.43 333.20 9 2.62 4.95 16.48 18.70 1.11 0.51 333.28 10 2.91 5.53 19.17 22.01 1.42 0.60 333.37 11 2.76 5.67 21.46 24.85 1.69 0.67 333.44 12 2.62 5.38 23.07 26.84 1.89 0.73 333.50 13 2.47 5.09 24.13 28.16 2.02 0.76 333.53 14 2.33 4.80 24.74 28.93 2.09 0.78 333.55 15 2.18 4.51 25.01 29.25 2.12 0.79 333.56 16 2.04 4.22 24.99 29.23 2.12 0.79 333.56 17 1.89 3.93 24.73 28.91 2.09 0.78 333.55 18 1.75 3.64 24.30 28.37 2.04 0.77 333.54 19 1.60 3.35 23.71 27.64 1.97 0.75 333.52 20 1.45 3.06 23.00 26.77 1.88 0.72 333.49 21 1.31 2.76 22.20 25.77 1.78 0.70 333.47 22 1.16 2.47 21.32 24.67 1.68 0.67 333.44 23 1.02 2.18 20.38 23.50 1.56 0.64 333.41 24 0.87 1.89 19.38 22.27 1.44 0.61 333.38 25 0.73 1.60 18.35 20.98 1.32 0.57 333.34 26 0.58 1.31 17.28 19.66 1.19 0.54 333.31 27 0.44 1.02 16.13 18.30 1.08 0.50 333.27 28 0.29 0.73 14.91 16.86 0.97 0.46 333.23 29 0.15 0.44 13.63 15.35 0.86 0.42 333.19 30 0.00 0.15 12.29 13.77 0.74 0.38 333.15 31 0.00 0.00 11.02 12.29 0.63 0.34 333.11 32 0.00 0.00 9.95 11.02 0.54 0.31 333.08 33 0.00 0.00 9.03 9.95 0.46 0.28 333.05 34 0.00 0.00 8.25 9.03 0.39 0.25 333.02 35 0.00 0.00 7.59 8.25 0.33 0.23 333.00 36 0.00 0.00 7.00 7.59 0.29 0.21 332.98 37 0.00 0.00 6.48 7.00 0.26 0.20 332.97 38 0.00 0.00 6.01 6.48 0.23 0.18 332.95 39 0.00 0.00 5.59 6.01 0.21 0.17 332.94 40 0.00 0.00 5.20 5.59 0.19 0.16 332.93 41 0.00 0.00 4.85 5.20 0.18 0.15 332.92 42 0.00 0.00 4.53 4.85 0.16 0.14 332.91 43 0.00 0.00 4.24 4.53 0.15 0.13 332.90 44 0.00 0.00 3.97 4.24 0.13 0.12 332.89 45 0.00 0.00 3.73 3.97 0.12 0.11 332.88 Garrett Engneering-4444 Carter Creek Parl<way SUie 108 -Bryan, Texas nao2 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 32 "' 46 0.00 0.00 3.51 3.73 0.11 0.11 332.88 47 0.00 0.00 3.30 3.51 0.10 0.10 332.87 48 0.00 0.00 3.12 3.30 0.09 0.09 332.86 49 0.00 0.00 2.95 3.12 0.08 0.09 332.86 50 0.00 0.00 2.80 2.95 0.08 0.08 332.85 51 0.00 0.00 2.66 2.80 0.07 0.08 332.85 52 0.00 0.00 2.53 2.66 0.07 0.08 332.85 53 0.00 0.00 2.40 2.53 0.06 0.07 332.84 54 0.00 0.00 2.28 2.40 0.06 0.07 332.84 55 0.00 0.00 2.17 2.28 0.06 0.07 332.84 56 0.00 0.00 2.06 2.17 0.05 0.06 332.83 57 0.00 0.00 1.96 2.06 0.05 0.06 332.83 58 0.00 0.00 1.86 1.96 0.05 0.06 332.83 59 0.00 0.00 1.77 1.86 0.05 0.05 332.82 60 0.00 0.00 1.68 1.77 0.04 0.05 332.82 Garrett Eni;neering-4444 Carte< C.-eek Parttway Suite 108 -Bryan. Texas 77802 -Te!ei:t>one: (409) 846-2688 -Fax: (409) 846-3094 -Page 33 • Inflow/Outflow Simulation 50-Year Storm Event 5 .00 4.50 \ ' 4.00 J -3.50 "C c 0 f I u Q) "' 3.00 .... Q) Q. I ! • ... ' ! l Q) Q) 2.50 J \ u. f u .· I \ :.c :J 0 'i' 2 .00 0 5 :J 0 1 .50 I I f ,/ 1.00 ./ •j ., 0 .50 0.00 0 10 -····---Pre- Development Hydrograph ' 20 30 40 50 Time (Minutes) • Post- Development Outflow Hydrograph Without Detention ----Post-- - - --- -Post- Development Development Outflow With "Free-Flow" Detention Garrett Engneering -4444 Corter C""'k Pori<woy SUie 108 -Bryon, TeX3s 77802 -Telephone: (409) 846-2688 • Fox: (409) 846-3094 -Page 34 60 Inflow I Outflow Simulation 100-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 332.77 1 0.30 0.30 0.29 0.30 0.01 0.01 332.78 2 0.61 0.91 1.14 1.20 0.03 0.03 332.80 3 0.91 1.52 2.53 2.66 0.07 0.08 332.85 4 1.22 2.13 4.35 4.65 0.15 0.13 332.90 5 1.52 2.73 6.55 7.08 0.27 0.20 332.97 6 1.82 3.34 8.98 9.89 0.45 0.27 333.04 7 2.13 3.95 11.57 12.93 0.68 0.36 333.13 8 2.43 4.56 14.29 16.13 0.92 0.44 333.21 9 2.73 5.16 17.12 19.46 1.17 0.53 333.30 10 3.04 5.77 19.88 22.89 1.50 0.62 333.39 11 2.89 5.92 22.23 25.81 1.79 0.70 333.47 12 2.73 5.62 23.88 27.85 1.99 0.75 333.52 13 2.58 5.32 24.96 29.19 2.12 0.79 333.56 14 2.43 5.01 25.59 29.97 2.19 0.81 333.58 15 2.28 4.71 25.85 30.30 2.22 0.82 333.59 16 2.13 4.40 25.81 30.25 2.22 0.82 333.59 17 1.97 4.10 25.54 29.91 2.19 0.81 333.58 18 1.82 3.80 25.07 29.34 2.13 0.79 333.56 19 1.67 3.49 24.46 28.57 2.06 0.77 333.54 20 1.52 3.19 23.71 27.65 1.97 0.75 333.52 21 1.37 2.89 22.87 26.60 1.86 0.72 333.49 22 1.22 2.58 21.95 25.45 1.75 0.69 333.46 23 1.06 2.28 20.96 24.22 1.63 0.66 333.43 24 0.91 1.97 19.92 22.93 1.51 0.62 333.39 25 0.76 1.67 18.83 21.59 1.38 0.59 333.36 26 0.61 1.37 17.72 20.20 1.24 0.55 333.32 27 0.46 1.06 16.55 18.78 1.12 0.51 333.28 28 0.30 0.76 15.29 17.31 1.01 0.47 333.24 29 0.15 0.46 13.97 15.75 0.89 0.43 333.20 30 0.00 0.15 12.58 14.12 0.77 0.39 333.16 31 0.00 0.00 11.27 12.58 0.65 0.35 333.12 32 0.00 0.00 10.16 11.27 0.56 0.31 333.08 33 0.00 0.00 9.21 10.16 0.47 0.28 333.05 34 0.00 0.00 8.40 9.21 0.40 0.26 333.03 35 0.00 0.00 7.72 8.40 0.34 0.23 333.00 36 0.00 0.00 7.12 7.72 0.30 0.22 332.99 37 0.00 0.00 6.58 7.12 0.27 0.20 332.97 38 0.00 0.00 6.10 6.58 0.24 0.18 332.95 39 0.00 0.00 5.67 6.10 0.22 0.17 332.94 40 0.00 0.00 5.28 5.67 0.20 0.16 332.93 41 0.00 0.00 4.92 5.28 0.18 0.15 332.92 42 0.00 0.00 4.59 4.92 0.16 0.14 332.91 43 0.00 0.00 4.30 4.59 0.15 0.13 332.90 44 0.00 0.00 4.02 4.30 0.14 0.12 332.89 45 0.00 0.00 3.78 4.02 0.12 0.11 332.88 Garrett Engineering· 4444 Corter Creek P3r1<way S<.ite 108 • Btyan, Texas 77802 • Telelilooe: (409) 84&-2688 • Fox: ("409) 84&-3094 -P3ge 35 fll 46 0.00 0.00 3.55 3.78 0.11 0.11 332.88 47 0.00 0.00 3.34 3.55 0.10 0.10 332.87 48 0.00 0.00 3.16 3.34 0.09 0.09 332.86 49 0.00 0.00 2.99 3.16 0.09 0.09 332.86 50 0.00 0.00 2.83 2.99 0.08 0.09 332.86 51 0.00 0.00 2.69 2.83 0.07 0.08 332.85 52 0.00 0.00 2.55 2.69 0.07 0.08 332.85 53 0.00 0.00 2.43 2.55 0.06 0.07 332.84 54 0.00 0.00 2.30 2.43 0.06 0.07 332.84 55 0.00 0.00 2.19 2.30 0.06 0.07 332.84 56 0.00 0.00 2.08 2.19 0.05 0.06 332.83 57 0.00 0.00 1.98 2.08 0.05 0.06 332.83 58 0.00 0.00 1.88 1.98 0.05 0.06 332.83 59 0.00 0.00 1.78 1.88 0.05 0.05 332.82 60 0.00 0.00 1.69 1.78 0.04 0.05 332.82 Garrett Engineering-4444 Carter Creek Par1<way Suite 108-Bryan, Texas 77602 -Telephone: (409) 646-2686 -Fax: (409) 646-3094 -Page 36 11111 Inflow/Outflow Simulation 100-Year Storm Event 5 .00 4.50 4 .00 -3 .50 i 'C I I c 0 f.J Cl) "' 3.00 .... Cl) a. .. Cl) Cl) 2 .50 l LL f.J .Q I ! :::J ' 0 -; 2.00 I I 0 !5 :::J 0 1 .50 ,' / 1 .00 'f 'I .i ... 0 .50 0 .00 0 10 ----·---Pre- Developmen t Hyd rograph 20 30 40 50 Time (Minutes) • Post- Developme nt Outflow Hydrograph W ithout Detention ----Post- - - -- ---Post- Development Develop ment Outflow W ith "F ree -Flow" Detention Garrett Engineering-4444 Carter Creek Par1<way SUie 108 -Bryan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Page 37 60 Inflow/Outflow Simulation 2-Year Storm Event 2 .50 2 .00 -'Cl c 0 u Cl) 1 .50 en ... Cl) c.. ... Cl) Cl) u. (,) :c :::I ~ ~ 1 .00 0 5 :::J 0 0 .50 0 .00 0 10 20 30 40 50 60 Time (Minutes) ----Pre-Development Hyd rograph ---•Total Post-Development Hydrograph Garrett Engineering· 4444 Carter C<eek Parkway 5uite 108 • Bryan. Texas n802 ·Telephone: (40Q) 846-2688 • Fax: (40Q) 84&-Jllll.4 • Page 38 • Inflow/Outflow Simulation 5-Year Storm Event 3 .00 2.50 ~ 2 .00 c: 0 u Q) "' ... Q) a.. -Q) Q) 1.50 LL \ i u I :c ::J (..) -~ 0 5 ::J 0 1 .00 \ \ \ \ 0 10 20 30 40 50 60 Time (Minutes) ---~-Pre-Development Hydrograph ---Total Post-Development Hyd rograph Garrett Ensjneering-4444 Carter Creek Pan<wa y Suite 108 -!!<Yan, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 84&-3094 -Page 39 Inflow/Outflow Simulation 10-Year Storm Event 3 .00 2 .50 :c-2 .00 c: 0 (,,) OJ en ... OJ D.. -OJ OJ 1 .50 ~ (,,) :0 I :I (..) I -~ 0 I 5 :i 0 1 .00 I I 0.50 0 .00 0 10 20 30 40 50 60 Time (Minutes) ---Pre-Development Hyd rograph ---Total Post-Development Hydrogra ph Garrett Engneering -4444 Carter Creel< Part<way Suite 108 -Bryon, Texas 77802 -Teiejmne: (409) 846-2688 -Fax: (409) 846-3094 -Page 40 Inflow/Outflow Simulation 25-Year Storm Event 3.50 3 .00 2.50 :a-c: 0 u Cl,) "' ... 2 .00 Cl,) a.. I -Cl,) Cl,) u. u l :0 :::s ~ 1 .50 ~ 0 I !5 :::s 0 1 .00 0 .50 0 .00 0 10 20 30 40 50 60 Time (Minutes) ----Pre-Development Hydrograph ---Total Post-Development Hydrograph Gorrell Engineering· «44 Carter Creek Parl<way Suite 108 ·Bryan . Texas 77802 ·Telephone: (4~) 84&-2688 ·Fax; (409) 846-3094 • Page 41 - 4 .00 3.50 3 .00 -"C c: 8 2 .50 G> en ... G> Cl. ... G> ~ 2 .00 u :c :J 0 -~ 0 = 1 .50 :J 0 1 .00 0 .50 0 .00 Inflow/Outflow Simulation 50-Year Storm Event ' \ \ \ 1 0 10 20 30 40 50 60 Time (Minutes) ----·· Pre-Development Hydrograph ---Total Post-Development Hydrograph Gamitt Engineering-«-44 Carter Creek Par1<way &>le 108 -Bryon, Texas 77802 -Telephone: (409) 846-2688 -Fax: (409) 846-3094 -Poge 42 Inflow/Outflow Simulation 100-Year Storm Event 4 .00 3.50 3 .00 -"O c 0 2 .50 u Cl> t/) ... Cl> c.. -Cl> cu 2 .00 u. u :c ~ I ~ :: 0 = 1.50 I ~ 0 1 .00 0.50 \ 0.00 0 10 20 30 40 50 60 Time (Minutes) Pre-Development Hydrograph ---Total Post-Development Hydrograph Garrett Engneering • 4-444 Carter creek Par1<way suto 108 -Bryan. Tens n802-Telephone: (409) 846-2688 -Fax: ('4C)g) 846-3094 • Page 43 GI E ::s 0 > E ::s E '>C cu ~ .... 0 -c: GI u ... GI Q. Detention Pond Storage Volumes as Percent of Maximum Volume 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2-year 5-year 10-year 25-year 50-year 100-year Design Storm Storm Simulation Synopsis 2-year 5-ear 10-year 25-year 50-year 100-year Storm Depth 0 .51 0 .60 0 .65 0 .72 0.79 0 .82 Storm Elevation 333 .28 333 .37 333 .42 333.49 333 .56 333 .59 Storm Volume 529 615 670 740 814 842 Maximum Capacity 866 866 866 866 866 866 Percent of Capacity 61% 71% 77% 86% 94% 97% Garrett Engneoring-4444 Carter Cl"eek Port<way SUie 108-B!yan, Texos n so2-Tele!mne: (409) 846-2688 -Fax: (409) 846-3094 -Page 44 Cl> E ..:! 0 > E :I E ')( CIS :E .... 0 -c: Cl> u '-Cl> a. Detention Pond Storage Volumes as Percent of Maximum Volume 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2-year 5-year 10-year 25-year 50-year 100-year Design Storm Storm Simulation Synopsis 2-year 5-ear 10-ear 25-year 50-ear 100-ear Storm Depth 0.51 0.60 0.65 0.72 0.79 0.82 Storm Elevation 333 .28 333 .37 333 .42 333 .49 333 .56 333.59 Storm Volume 529 615 670 740 814 842 Maximum Capacity 866 866 866 866 866 866 Percent of Capacity 61% 71% 77% 86% 94% 97% Garrett Ef9neering-4444 Carter Creek Pa11cwoy Suite 108 ·Bryan, Texas n802 • Telept\o!>e: (409) 846-2688 -Fax: (409) 846-3094 • Pago 44 l-.... •_> ·' '. -.-; .. MEMORANDU l 1~199 ·---- :~ta?i !f?.;"1:i.1w\;d 1·1e ai:.iove -mtintioned isits· plan --s reque::>tL:d r. B f1::il1chvi:'i£; i:~~!::le i: ~1 !!-:; 0+ st:"; ff re vie .-v curnrc~Ail s d t::Jlling itEJms tha:: nHti-Q to .J ,: addi ef:.._;2d PiiJdS'-' ;;; :: .... :, ··~_; tr1r.: cornn1r,nt-;; and ·u rnit the follo1Ning inforrnahnn _;f furtt1e 1 ~ -;ff :f-!vic·,·• t112u (.'.') 'J)lltµl~te sets c.•t bu1~ding Gonstruct"or: !J!Ui.iOS(~... r•cvel<JpmE=1nt itl the r ~' !s.:Yl '::Ii €: on <.;t1ached; and f il..:if"'°? ...re COi l/ ,.tjl 1l:; thai you are not cJrldressing ..\<ith rh1.'] revi:>ed "iii? plG.il, ~·:1:: · :.::.·:-' <~Lrac!·1 ;:J ict!·'~~ t:-.':;-1~:~'1ng the details. If y .. :-u hE!vH t:.·my qtJc;;tiOr"\£ !): i.uc( ::J:"idil:or ;i • • • ,. t '""' 3 -o 1r11c:m. 3llu 1, ;J:er:ise ·-~!I m1:: a ... v -.; ,) r . CC. R.:-:IJi.:• t. Sc:ils. ?.204 r·erber Cirr.te .. Cllegc !:i!~.,fr:Jn, Tt:,:'as, 7TR--iS '::~ SC filt-: #99 437 .:... :!.! 1'N on 7(l.: '.s-196 DEVELoPMF\'T SVCS STAFF REVIEV\I COMMENTS No. 1 ,1ld8' the telephone number for the Owner f'rTNf<ie th€· r..iri eway throat englh dimension. Al:o providti the di~rancc fo: the :;.d1"'eent stiee 'drivew::w, and al~o rn 'lm1 openings on Hock Pram Rord Ch· r 1ge t €' E\8 fi:~et P rivl':l t G Ac ... e~s Eas.s: ent to Pnvata .u. ":cess unCi Lirainage E8scment ,,. Fie v1df; w:..ter m~!.A locutions. { -iGng~ tne -ar set back dimension from 7' .5 feet !o 15 tc::i t. ,, Clari :· rnat<~n~ I u'Sed on scr·-:iemng fence for the dump .. t--c. Provide transformer lo cation . ab0v~ and l1•·1derground se:-l"h.>:: :.zm fl(:~.,,0;1 s to 1 he ouild1ng S v 'N F 1ff: Lanes for th ~ driv~way entry up to bul net \nCh.Kfi!lG ~r1e parh.1nd wti·1 s1n....e tit~ oac of the btJilding is morn tha11 ·150 foe: from the curb !111r~ c•r pavvmen . <~< g~ of the public street. 9. R1.. c:k Pt;i;nB Roe1d :s a major arter ia l ~ B :.h wri on t 1a Cit: ' , Thorcu '.]ht ~ir~ P!an; thE=> stree isc~p'.3 poin' riaquirenient is 1 c.anop_ ti t.e pe~ :;::s foe. ,f 'ront3ge (6 tre;es). 1t) Thi'? par .ng i t . -".;rt.~e n ing alor~g Rock Prn1ri~ Road is to be cont ii ,ur--1 1s witho11l ~J8;2•S between ~hrubs. 11. P!«.>v n.le -s .. :r9ening for the pmpo~e(i rnnsfor1 ne1 , · Jc 1Jntt , ana µc.11:1t ,·8rv1c2 conPcchons. t o the buil·'ir;g 12 . Provide an ir igaton system pl::.n prior to hE: C . ( 13. Provide a leger1ci f r the V•r 1er and sanitary sewer derr.ands ·14 The c '"rlifica ·ion signatures of the surv~)1 Dr and enr ,neer G1re r £;qui~·(Jd : ·, the ..;,,te ~!an. 1 ~~ Staff ht-1s not comple,E:d lhe drainage and grad1n~: pi~r .s . ~f!\..l \•,{!fi 'y Vi:lfd thF.< comm n t:--tor the e wh ~~n the re 1ew is compl0te Peviewerj tiy D. te-A-16 -99 Review Date: __________ _ plication Fee ($100) plication . Erosion Control Plan 4. EPA/NOI (> 5 acres) 5. Public Infrastructure Inspection Fee ($300) ~. Drainage Report ,:r~ 7. HOA Covenants for maintenance of detention/retention ponds .. y~ 8. Easements Dedicated (separate instrument) lif f\. 9. TXDOT permits issued 'YA 10 . Enginccr1 5 'Estimates (14 necessaey for rough grading/clcariog ....... all others necessaey for full permit) 11 ol12 DEVELOPMENT PERMIT CITY OF COLLEGE STATION 1101 TEXAS AVE COLLEGE STATION, TX 77840 PHONE: (409) 764-3741 FAX: (409) 764-3814 Application Number Property Address Property ID . . . . Application description Subdivision Name Property Use 99-00500294 Date 112 ROCK PRAIRIE RD DEVELOPMENT-AREA'S INSIDE SFHA BUSINESS Property Zoning . GENERAL COMMERCIAL Owner Contractor OWNER Permit . . . . Additional desc Permit Fee Issue Date DEVELOPMENT PERMIT 100.00 9/13/99 Special Notes and Comments THE CONTRACTOR SHALL TAKE ALL NECESSARY PRECAUTIONS TO PREVENT SILT AND DEBRIS FROM LEAVING THE IMMEDIATE CONSTRUCTION SITE IN ACCORDANCE WITH THE APPROVED EROSION CONTROL PLAN AS WELL AS THE CITY OF COLLEGE STATION DRAINAGE POLICY AND DESIGN CRITERIA. THE OWNER AND/OR CONTRACTOR SHALL ASSURE THAT ALL DISTURBED AREAS ARE SODDEN AND ESTABLISHMENT OF VEGETATION OCCURS PRIOR TO REMOVAL OF ANY SILT FENCING OR HAY BALES USED FOR TEMPORARY EROSION CONTROL. THE OWNER AND/OR CONTRACTOR SHALL ALSO INSURE THAT ANY DISTURBED VEGETATION BE RETURNED TO ITS ORIGINAL CONDITION, PLACEMENT AND STATE. THE OWNER AND/OR CONTRACTOR SHALL BE RESPONSIBLE FOR ANY DAMAGE TO ADJACENT PROPERTIES, CITY STREETS, OR INFRASTRUCTURE DUE TO HEAVY MACHINERY AND/OR EQUIPMENT. ANY TREES REQUIRED TO BE PROTECTED BY ORDINANCE OR AS PART OF THE LANDSCAPE PLAN MUST BE COMPLETELY FENCED BEFORE ANY OPERATIONS OF THIS PERMIT CAN BEGIN. 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 Valuation 9/13/99 0 DEVELOPMENT PERMIT CITY OF COLLEGE STATION 1101 TEXAS AVE COLLEGE STATION, TX 77840 PHONE: (409) 764-3741 FAX: (409) 764-3814 Appli c ati~:m Number . . . . . 99 -00500294 Special Notes and Comments CONSTRUCTION, EROSION AND SEDIMENTATION SHALL NOT BE DEPOSITED IN CITY STREETS, OR EXISTING DRAINAGE FACILITIES. I HEREBY GRANT THIS PERMIT FOR DEVELOPMENT OR AN AREA INSIDE THE SPECIAL FLOOD HAZARD AREA. ALL DEVELOPMENT SHALL BE IN ACCORDANCE WITH THE PLANS AND SPECIFICATIONS SUBMITTED TO AND APPROVED BY THE CITY DEVELOPMENT ENGINEER AND ALL OF THE CODES AND ORDINANCES OF THE CITY OF COLLEGE STATION THAT APPLY. ADMINISTRATOR SIGNITURE: DATE : ~-,, :sza;;; I CONTRACTO~OWNER SIGNITURE: DATE: 9/JS/CfJ **************************************** **************************************** Fee summary Charged Pa i d ------------------------------------- Permit Fee Total 100.00 100.00 Grand Total 100.00 100.00 BUILDING DEPT REPRESENTA APPLICANT: Credited ---------- .00 .00 Page Dat e Du e 2 9/13 /99 ---------- .00 .0 0 1 / l FOR OFFICE US E CASE NO .. __ _ DATE SUBMITI'ED SITE PLAN APPLICATION MINIM1JM SUBMITfAL REQUIREMENTS ~ite plan application completed in full. ~ ~ _ . ~$100.00 Application Fee. · ~- V-$100.00 Development Permit Application Fee. -!!Ji $300.00 Pu~lic Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public waterline, sewcrline, sidewalk, street or drainage facilities is involved.) ...i,L. Ten (10) folded copies of site plan. . ~ A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they checked off. APPLICATION DATA NAMEOFPROJECT !WUIJfl!< ~1rlf.(I t<WTf:lf. -~ 1~ _)/;Of! ADDRESS ~~ll~Jr------'k~(tl~~P~M~J~fi ~U~d ~~· ~~~~~~~~~ LEGAL DESCRIPTION 1,.,oy 2.-t B.l.<X.-k T>vu ; £flj£.LW£Hf ~£rs ct:/llW£; O,q,g~ AL APPLICANT (Primary Contact for the Project): Name G AR-ee=tT W'11Ne61?.1 tJq {~c. -Dekn.tA\ Street Address 1/1/'f'f Ctr;rt.f(A. C-11-LO< f/a.J t !>urD! 10 g City _,t&y,~,....w~-------- State TX Zip Code 77'! D -i.. E-Mail Address _________ _ Phone Nwnber __.._t~Y("--_V_9i'..__ _____ Fax Nwnber --------------- PROPER1Y OWNER'S INFORMATION: Name (2.p&to:: . >ELIA Street Address 1-1-0 't. rfMErt c.1(UL£ City @Lj;6-£ffATI &J Stcitc T>< Zip Code 77' <u-E-Mail Address ---------- Phone Nwnbcr -----------'--Fax Nwnbcr ______________ _ ARCIDTECT OR ENGINEER'S INFORMATION: Name ~£tr £,.J.,_/;Vf.e&,JG- StreetAddress lfl#& ~·(./!£Lie tltJ#. !JHTi toi City _A__~=ui~...::__ ______ _ State 1);2 Zip Code ·77$0'4 E-Mail Address ---------- Phone Number ivt-2-tg1 FaxNwnber ______________ _ OTHER CONTACTS (Please specify type of contact, i.e. project manager, potential buyer, local contact, etc.) Name -------------------------=-------- StreetAddrcss ----------------City ----------- State Zip Code _____ E-Mail Address ---------- Phone Number Fax Nwnbcr SITE PLAN APPLICATION SITEAPP.IX>C OJnS/99 --------------- .. SUPPLEMENTAL DEVELOPMENT PERMIT INFORMATION Application is hereby made for the following development specific waterway altera.tions: ACKNOWLEDGMENTS: fGJ\>°\e.. ?k\\S I, · 1-e...:> TuolMa.5 D61}:Nn csN 13>ND ' 12..qz-~i.Nl! id ·, design engineer/owner, hereby acknowledge or affirm that 1be information aii<l conclusions contained in the above plans and supporting documents comply with the current requirements ol the City of College Station, Texas City Code, Chapter 13 and its associated Drainage Policy and Design Standards. As a condition of approval of this permit application, I agree to construct the ~provements proposed in this application accordinf th~en ~ requirements of Chapter 13 of the College Station City Code. ~~ A. . I, certify that any nonresidential structure on or proposed to be on this site as pa of this application is designated to prevent damage to the structure or its contents as a result of flooding from the 100 year storm. Engineer Date B. I, certify that the finished floor elevation of the lowest floor, including any basement. of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended. Engineer Date C. I , , certify that the alterations or development covered by this permit shall no t diminish the flood~ng capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent With requirements of the City of College Station City Code, Chapter 13 concerning encroachments of floodwaysandoffloodwayfringes. Engineer Date . . D . I, do certify that the proposed alterations do not raise the levcl of the 100 year fl~ above elevation established in the latest Federal Insurance Administration Flood Ha7.ard Study . Engineer Date Conditions or conunents as part of approval :-------------,.---------------- In accordanee with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to 'insure that deb from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. T hereby grant this permit for development. All development shall be in accordance with the plans and Specifications submitted to and approved by the City Engineer for the above named project All of the applicable codes and ordinances of the City of College Station shall apply. SITE PLAN APPLICATION SITEAPP.DOC 03125199 3 of 3 ProjectNamc: M/we1sz .fk-~ ~ Review Date:___.;.~____:;,-4-_17,__~---- Reviewer :. ___________ _ Drainage Reports Location JJA D Primal)' drainage system identified ffet 0 Surrounding developments shown >1' Local strccts, drainage systems shown Description !!, Acreage of project :,el Land cover described NA 0 Primal)'/scc:oodary systems within property shown ,ff General ~ption Drainage Basins AJA o R.cfercnccs to FIRMs if applicable '1/A D Secondary system flow patterns and impact of development on existing system ..f)A-0 Proposed pathways to Primal)' system shown or described Design Criteria J.)o 0 Ally deviation from standards being requested? 11/o D Discussion of site constraints and capacities (streets, existing structures, etc .) Ah 0 Discuss ion of any applicable previous drainage studies and how this plan will affect it Hydrologic Criteria Ff, Rainfall/runoff calculation method described and calculations provided gr' Detention discharge I storage calculation method I calculations %_ S&orm n:currencc intcrva15 used pf Discussion of other drainage facility design criteria used if not referenced in Standards dauli riteria Identify capacity of systems used Specify velocities at critical points in system Identify detention I retention outlet and routing Discussion of other drainage facility design criteria used not referenced in Standards Drainage Facility Dqign J! Discuss drainage paucma /flows (pre vs. post) ~o/ D Axe they draining water onto another property owner? -if so, is it where the water flowed before? and is it not { more than what flowed there before? and no faster than it flowed before? 0 Discuss erosion control mcaswcs employed yj Discuss detention pond design (sideslope, low flow cbaooels, outlet works, frceboard, emergency spillway) No 0 Discuss maintenance access and responsibilities JI I Conclusions ;vr;. 0 Verify compliance with DPDS (signed and sealed certification) 0 Explain effectiveness of improvements with regard to controlling discharges of S -100 year storm by a) Detaining b) Aocommodating runoff in existing I proposed casements or ROW discharging into primary system c) Combination of a & b 9 ot'12 Project Name: Gih!€d 7~ r!HJ 5~ Review Datc:--'4s.............,<~.....:.(_..;..7 __,~----- Reviewer: ___________ _ Drainage Reports(cont.) AopendicCJ B References (all criteria and technical infonnation used) Jtf Hydrologic computations J1. Land use assumptions for adjacent property Z Minor/major storm runoff at specific points Jlf Historiclfully developed runoff specific points % Hydrographs at critical points J' Hydraulic computations 0 Culvert capacities (headwater and tailwater assumptions) 0 Storm sewer capacities 0 Street capacities 0 Storm inlet capacities (inlet control rating) 0 Open channel design ~ Detention area I volume capacity I outlet capacity Attached Drawings A Location map with drainage patterns 'pf Floodplain map if any 'f1. Drainage plan with topo (existing and proposed with arrows if needed) 'Ji Details of outlet structures 10 oll2 .. , '· Project Name:. __________ _ Review Date: __________ _ Reviewer: ___________ ~ TXDOT PERMIT CHECKLIST 0 Permit signed (Utility or Driveway) by owner 0 Set or excerpts of construction plans of what is proposed within ROW 0 Traffic Control Plan (TMUfCD) 0 Drainage Calculations (if applicable) For City Uae 0 Sign permits 0 Attach cover letter 0 Submit in triplicate to TxDOT 12 all2 LOOK IN CONFIDENTIAL BINDER FOR OTHER SUPPORTING MATERIAL