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Home My WebLink AboutFolderFOR OFFICE USE ONLY Case No. 0~ 55 Date Submitted J J.,-q' -D ~ DEVELOPMENT PERMIT MINIMUM SUBMITTAL REQUIREMENTS ~ $200.00 development permit fee. ~ Drainage and erosion control plan, with supporting Drainage Report two (2) CO);>. ies each D Notice of Intent (N.0.1.) if disturbed area is greater than 5 acres y 5o LEGAL DESCRIPTION Harvey Hillside. Block One. Lot 42. 5.36 acres. Maria Kegans A-28 APPLICANT (Primary Contact for the Project): Name Rabon Metcalf (RME) E-Mail rmengineer@juno.com Street Address P.O. Box 9253 City College Station State TX Zip Code 77842 Phone Number (979} 219-4174 Fax Number (979} 690-0329 PROPERTY OWNER'S INFORMATION: Name Mark Dudley E-Mail Street Address 11370 SH 30 City Qollege Station State TX Zip Code 77845 Phone Number (979} 776-2135 Fax Number (979) 776-2235 ARCHITECT OR ENGINEER'S INFORMATION: Name Same as Aeelicant E-Mail Street Address City State Zip Code Phone Number Fax Number Application is hereby made for the following development specific site/waterway alterations: 48" RCP Storm sewer imerovements in call Tributary "A" of Carters Creek watershed ACKNOWLEDGMENTS : I, Rabon A. Metcalf. P.E. <Engineer), design engineer/owner, hereby acknowledge or affirm that: 1 :3() "' The information and conclusions contained in the above plans and supporting documents comply with the current requirements of 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 improvements proposed in this application according to these documents and the requirements of Chapter 13 of the College Station City Code Property Owner( s) 1-Aug-02 Contractor 1 of2 CERTIFICATIONS: (for proposed alterations within designated flood hazard areas.) A. I, NIA, certify that any nonresidential structure on or proposed to be on this site as part of this application is designated to prevent damage to the structure or its contents as a result of flooding from the 1 oo year storm. Engineer Date B. I, NIA, 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, Rabon A. Metcalf. P.E., certify that the alterations or development covered by this permit shall not diminish the flood-carrying 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 nceming encroachments of floodways and of floodways fringes. -------- Date D. I, Rabon A. Metca P.E., do certify that the proposed alterations do not raise the level of the 100 year flood above ele ion established in the latest Federal Insurance Administration Flood Hazard Study. --+---rr-, Date ,_. Conditions or comments as part of approval:---------------------- 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. All development shall be in accordance with the plans and specifications 1-Aug-02 2of2 .. -... 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. 1-Aug-02 3 of 2 02/12/03 WED 12:36 FAX 979 6900329 RME FACSIMILE TRANSMITTAL SHEET TO: FROM: Carroll Cotter Rabon Metcalf, PE. COMPANY: DATE: City of College Station 2/12/03 FAX NUMBER: TOT.AL 7; PAGES INCLUDING COVER; PHONE NUMBER: CC: RB: CC FAX NUMBER: Dudley Drainage 0 URGENT ~OR REVIEW 0 PLEASE COMMENT 0 PLBASE REPLY 0 FOR YOUR RECORDS NOTES/COMMENTS: Please find attached the TxDCIT TR-55 modeling method. I will take a close look at my spreadsheet and make sure I do not have any errors. I am currently finalizing the existing and proposed condition models. I have been working with Brett on OP possibilities for replacement of the existing 48" under Pamela lane. If possible, could we schedule a meeting sometime next week with yourself and Brett to discuss my findings and an OP request. Thanks for the help. Rabon The information contained in this fux is confidential and is exclusively fur the use of the previously addressed party. Please call ihe above number to correct any difficulties with the tniosmission of 1his fux. 14!001 02/12/03 WED 12: 37 .FAX 9_7~~00329_ RME -.. ·-.. -..;:.. 5. 7 :NRCS RUNOFF Cu'RVE NUMBER METHODS 5. 7.1 Introduction to NRCS Methods The department has adopted two specific runoff determination techniques developed by the US Depamnent of Agriculture Natural Resource Conservation Service(NRCS), formerly known as the Soil Conservation Service (SCS): a graphical peak discharge method and the dimensionless unit hyd.rograph method. The techniques require basic data similar to that used in the Rational Method. However, the l'o'RCS approach is-more sophisticated io that it considers the time distribution of rainfall, initial rainfall losses to interception and depression storage, and an infiltration rate that decreases during the course of a stonn. The NRCS methods produce the direct runoff for a storm. either real or fabricated, by subtracting infiltration and other losses from the total rainfall using a method sometimes termed the Runoff Curve Number Method. The primary input variables for the NRCS methods are + drainage area size (A) in square kilometers + time of concentration (Tc) in hours + weighted runoff curve number (RCN) + rainfall distribution (NRCS Type II or Ill for Texas) • total design rainfal1 (P) in millimeters The procedures presented here are derived from the NRCS National Engineering Handbook, Section 4 and Hydrology for Small Urban Watersheds, Technical Release Number 55. 5.7.2 NRCS Rainfall-Runoff Equation Equation 5. 7-1 represents a relationship between accumulated rainfall and accwnulated nm.off. This was derived by the NRCS from experimental plots for numerous soils and vegetative cover conditions. Data for land treatment measures, such as contouring and terracing, from experimental watersheds were included. where: R = p = la = s = R = (P-IJ2 (P-·I,)+ S ..........................................•........ 5.7-1 accumulated direct runoff (mm) accumulated rainfall (potential maximum runoff) (mm) initial abstraction including surface storage, interception, and infiltration. prior to runoff (nun) potential maxim~ retention (mm) The potential maximum retention (S) may be computed as the following: Fivdraulic Desi}!n S-3fi !41002 . 02112(03 WED 12:37 FAX 979 6900329 RME i Chapter 5-Hydrology Section 5.7-NRCS kunoff Curve Number Methods s = 25400 -254 RCN .................................................... 5.7-2 where: RCN= runoff curve number as described in Section 5.7.6 Equation 5 .7 ·2 is valid if S < (P-R). Equation (5. 7-2) was developed mainly for small watersheds from recorded stonn data that included total rainfall amount in a calendar da.y, but not its distribution with respect to time. Therefore, this method is appropriate for estimating direct runoff from 24-hour or 1-day storm rainfall. Generally, Ia may be estimated as the following: I. = 0.2S ··········-·······-······································· 5.7-3 which, when substituted in Equation 5-:-1--Z: gives ~.I~? R = (P-0.2 S)1 (P +0.8 S) .................................................... 5.7-4 5. 7.3 Accumulated Rainfall (P) For most highway drainage design purposes, the accu~ulated rainfall may be abstracted from Technical Paper 40 (:NWS, 1961) for a 24-bour duration storm for the relevant frequency. The data for 24-hour 2, 5, 10, 25. 50, and 100-year frequencies for Texas counties are presented in Appendix 5-2. 5.7.4 Rainfall Distribution There are two design dimensionless rainfall distributions for Texas; Type IT and Type ill which are shown in Figure 5.7-1. Figure 5.7-2 shows the areas in Texas ro which these distribution types apply. The distribution represents the fraction of accumulated rainfall (not runoff) accrued with respect to time. The differences between Type II and Type ill are minimal. Hwl.rm.1.lir. nl'.~i9.n 5.37 T.xDOT-09196 141003 02/12/03 WED 12:37 FAX 979 6900329 RME 141004 · · Chapler 5-Hydrology Section 5.7-NRCS RunojfCur-ve Number Methods :i c ~ ... ; .; ..,. o.a Colt 'S c: .3 ~ ~ u. • ' 1~ 15 ,. 24 Time ~hoursl Figure 5.7-1: Soi1 Conservation Service 24-hour rainfall distributions Adapted from TR.55 (1986, pp. B-1) D Typell Type ill _,. Figure 5.7-2 : Rainfall Distnbution Types in Texas ffydraulic Design 5-38 TvD{)T_J)O/OJ; 02/12/.03 WED 12: 38 FAX 979 6900329 RME Cho.pier 5-Hydrology Section 5. 7-NRCS R~r,off Curve Number Methods 5.7.5 Soil Groups Soil properties influence the relationship between rainfall and runoff by affecting the rate of infiltration. · The NRCS div1des soils into four hydrologic soil groups based on infiltration rates, groups A, B, C, and D which are described as follows: • Group A--Soils having a low runoff potential due to high infiltration rates even when saturated (7.6-1.4 mm/hr). These soils consist primarily of deep sands, deep loess, and aggregated silts. • Group B--Soils having a moderately low runoff potential due to moderate infiltration rates when saturated (3 .8 mm/hr to 7 .6 mm/hr). These soils consist primarily of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately coarse textures (shallow Ioess, sandy loam). • Group C-Soils having a moderately high runoff potential due to slow infiltration rates ( 1.3 mrnJhr to 3.8 mm/hr if saturated). These soils consist primarily of soils in \vbich a layer near the surface impedes the downward movement of water or soils with moderately fine to fine texture (clay loams, shallow sandy loams. soils low fo organic content, and soils usually· high in clay). + Group D---Soils having a high runoff potential due to very slow infiltration rates (1ess than 1.3 rrurubr if saturated). These soils consist primarily of clays with the following characteristics: • high swelling potential • soils with permanently high water tables • soils \l.ith a claypan or clay layer at or near the surface • shallow soils over nearly impervious parent material (soils that swell significantly when wet, heavy plastic clays. and certain saline soils) Consideration should be given to the effects of urbanization on the natural hydrologic soil group. If heavy equipment c_an be expected to compact the soil during construction or if grading will mix the surface and subsurface soils, appropriate changes should be made in the soil group selected. · 5.7.6 Runoff Curve Number (RCT'i) Rainfall infiltration losses primarily are dependent on soil characteristics and land use (surface cover). The NRCS method uses a combination of soil conditions and land use to assign runoff factors known as runoff cur,/e numbers. These represent the runoff potential of an area when the soil is not frozen. The higher the RCN, the higher the runoff potential. Tables 5.7·1 through 5. 7-4 provide an extensive list of suggested runoff curve nwnbers. The RCN values assume medium antecedent moisture conditions. If necessary, the designer should adjust the RCN for wet or dry antecedent moisture conditions. A five-day period.is used as the minimum for estimating antecedent moisrure conditions. i\ntecedent soil moisture conditions also vary during a storm; heavy rain falling on a dry soil can change the soil moisture condition from dry to average to wet during the Hvdraulic Desirzn 5-39 TxDOT-09196 ~005 02/12/03 WED 12: 38 FAX 979_Q_90032L ______ RME _______ _ storm period. Equation 5. 7-5 adjusts values for expected dry soil conditions (antecedent moisture condition I). Use Equation 5.7-6 to accommodate wet soils (antecedent moisture condition III). Table 5.1-5 assists the determination of which moisture condition applies. RCN(I) = 4.2RCN(II) ....................................... 5.7-5 10-0.058RCN(Il) .. 23RCN(Il) RCN(lll) = ....... : ................................ 5.7-6 10+0.13RCN(m f..f,vdraulic Design 5-40 Tr.nnr--fJ0101> 141006 02/12/03 WED 12 :38 FAX 979 6900329 RME Table 5. 7-1 : Runoff Curve Nwnbers for Urban Areas Cover type aod hydrologjc condition Average A a c D percent imne[YjQWi area Fully developed urban areas (vegetation eStablished) Open space (lawns, parks, golf courses, 68 79 86 89 cemeteries. etc.) Poor condition ( Ql'aSS cover <50%) Fair condition {grass cover 50% to 49 69 79 84 75%) Good condition f~s cover> 75%) 39 61 74 80 lmpervious areas: 98 98 98 98 Paved parking lots. roofs. driveways, etc. (excluding ri2ht-of-wav) S rreets and roads: 98 98 98 98 Paved~ curbs and srorm drains ( excludiniz riizhr-of-wav) Paved; open ditches (including right-of-83 89 92 93 wav) Gravel (includin2 ri2ht-of-wavl 76 85 89 91 Dirt (iocludin2 ri2ht-of-wav) 72 82 87 89 Western desert urban areas: 63 77 85 88 . Natural desert landscaping (pervious areas onlv} Artificial desert landscaping 96 96 96 96 (impervious weed barrier, desert shrub wich 1-to 2-inch sand or gravel mulch and basin borders) Urban districtS: Commercial and business 85 89 92 94 95 ! Indusrrial -? ,_ 81 88 91 93- Residential districts by average lot size: 118 acre or less (10~11 houses) 65 77 85 90 92 114 acre 38 61 75 83 87 113 acre 30 57 72 81 86 l /2 acre 25 54 70 80 85 l acre 20 51 68 79 84 2 acres 12 46 65 77 82 Developing urban areas Newly graded areas (pervious areas 77 86 91 94 onlv. no ve2etation) + Values in table are for average runoff condition and I. = 0.2S. • The average percent impervious area shown was used to develop the composite RCN's. Other assumptions are: (I) impervious areas are directly connected to the drain.age system, (:2) impervious areas have a RCN of 98, and (3) pervious areas are considered equivalent to open space in good hydrologfo condition. Hvdraulir. De.'iiP-n 5-41 TxDOT-09196 l4J 007 02/12/03 WED 12:39 FAX 979 6900329 . . RME Table 5 7 2 RunoffC -urve N b fi Culti ed A . ltural L d um ers or vat .gncu an Cover Treatment Hydrologic A B c D tvoe condition Fallow Bare soil -77 86 91 94 Crop residue Poor 76 85 90 93 cover (CR) Good 74 83 8'8 90 Row Straight row (SR) Poor 72 81 88 91 Crops Good 67 78 85 89 SR+CR Poor 71 80 87 90 Good 64 75 82 85 Contoured (C) Poor 70 79 84 88 Good 65 75 82 86 C+CR Poor 69 78 83 87 Good 64 74 81 85 Contoured & Poor 66 74 80 82 terraced ( C & T) Good 62 71 78 81 C&T+CR Poor 65 73 79 81 Good 61 70 77 80 S mali grain SR Poor 65 7.6 84 88 Good 63 75 83 87 SR+CR Poor 64 75 83 86 Good 60 72 80 84 c Poor 63 74 82 85 Good 61 73 81 84 C +CR Poor 62 '7" I :J 81 84 Good 60 i2 80 83 C&T Poor 61 72 79 82 Good 59 70 78 81 C&T+CR Poor 60 71 78 81 Good 58 69 77 80 Close-seeded SR . Poor 66 77 85 89 or broadcaSt Good 58 72 81 85 Legumes or C Poor 64 ~~ ,) 83 85 Rotation Good 55 69 78 83 Meadow C&T Poor 63 73 80 83 Good 51 67 76 80 + Values in table are for average runoff condition and Ia.= 0.25. • Crop residue cover applies only if residue is on at least 5% of the surface throughout the year. • Hydro logic condition is based on a combination of factors that affect infiltration and runoff. including (a) density and canopy of vegetative areas, (b) amount of year-round cover, (c) amq.unt of grass or closed-seeded legumes in rotations, ( d) percent of residue cover on the land surface (good> 20f"o), and (e) degree ofroughness. • Poor. Factors impair infiltration and tend to increase runoff. • Good: Factors encourage average and better than average infiltration and tend to decrease runoff. Hvdraulic Desif!n 5-42 TxDOT-09196 141008 02/12/03 WED 12: 39 .FAX 979 6900329 RME Chapter 5-Hydrology Section 5. 7-NRCS Runoff Curve Number Methods Table 5.7-3: Runoff Curve Numbers for other Agricultural Lands Cover type Hydrologic A B c condition Pasture, grassland. or range-Poor 68 79 86 continuous forage for grazing Fair 49 69 79 Good 39 61 74 Meadow-continuous grass. 30 58 71 protected from grazing and generally mowed for hay Brush-brush-weed-grass mixture, Poor 48 67 77 with brush the major element fair 35 56 70 Good 30 48 65 Woods-grass combination Poor 57 73 82 (orchard or tree farm) Fair 43 65 76 Good .,.., -'~ 58 72 Woods Poor 45 66 77 Fair 36 60 73 Good 30 55 70 Farmsteads-buildings. lanes. 59 74 82 drivewavs. and surround.in!? lots • Values in table are for average runoff condition and la= 0.2S. + Pasture: Poor. < 50% ground cover or heavily grazed with no mulch Fair: 50 to 75% ground cover and not heavily grazed D 89 &4 80 78 83 77 73 86 82 79 83 79 77 86 Good:> 75% ground cover aod lightly or only occasionally grazed + Meadow: Poor: < 50% ground cover Fair: 50 to 75% ground cover Good:> 75% ground cover • \Voods/grass: RCN's shown were computed for areas with 50% grass (pasture} cover. Other ,,.. combinations of conditions may be computed from RCN's for woods and pasture • Woods: Poor: Forest litter, small trees, and brush are destroyed by heavy grazing or regular burning Fair: Woods. grazed but not burned, and some forest litter covers the soil Good: Woods protected from grazing, litter and brush adequately cover soil Hydraulic Desi~ 5-43 TrnnT-llOIOli 141009 02 /12/03 WED 12 :39 FAX 979 6900329 RME Table 5. 7-4: Runoff Curve Numbers for Arid and Semi-arid Rangelands Cover type Hydrologic A B c D condition Herbaceous--mixture of grass. Poor 8-0 87 93 weeds. and low-growing brush, Fair 71 81 89 with brush the minor element Good 62 74 85 Oak-aspen-mountain brush Poor 66 74 79 mixture of oak brush. aspen. fair 48 57 63 mountain mahogany. b itter Good 30 41 48 brush. maple. aod other brush Pi.n yon-j uniper-pinyon. Poor 75 85 89 juniper. or both; grass understory Fair 58 73 80 Good 41 61 71 Sagebrush with grass Poor 67 80 85 understory Fair 51 63 70 Good 35 47 55 Desen shrub--rnajor plants Poor 63 77 85 88 include saltbush, greasewood.. creosote-Fair 55 72 81 86 bush. blackbrush. bursage, palo Good 49 68 7.9 84 verde. mesouice, and cactus + Values in table are for average·runoff condition and r. = 0.2S. + Hydrologic Condition: Poor.< 30% ground cover (litter. grass, and brush overstory) Fair: 30% to 70% ground cover Good: > 70% ground cover + Curve numbers for Group A have been developed only for desert shrub. Hydraulic Desi1tn 5-44 rrnnT--flOIOfi 141010 02 /12/03 WED 12:40 FAX 979 6900329 RME Table 5. 7-5: Rainfall groups for antecedent soil moisture conditions during growing and dormant seasons Growing Sea.sen DocmancSeasm Antc:ccdent five-day five.<fay Condition Conditions Description Antecedent Anrccedmr Rainfall Rainfall An optimum condition of watershed soi.ls. !· ~t 'I ..j '7 where soils are dry rut DOt to che ·wilting point, DryAMCI and when satisfactory plowing or cultivatioo. Less than 35 mm Less than 12 mm takes olao: j -;i L.. o'f 0,-f1 , _, .. Ave:ra~AMC II The avera>(e case for annual floods 35 co 53 mm 12 to28 mm When a heavy rainfal~ or light rainfall and -z_.o ,. 1•/0 WetAMCill low temperatures, have occurred during the Ova53mm Over 28mm five davs orevious to a ~v01 storm 5.7.7 NRCS Graphical PeakDiscbarge Procedure (TR55) This method of peak: discharge determination can be used for relatively homogeneous watersheds with· a maximum time of concentration of 10 hours (600 minutes). In a similar fashion to the Rational Method, if soils and land use vary, the watershed should be subdivided. Precipitation records published in TP-40 and an assumed rainfall distribution are used to construct a synthetic storm. The method should not be used for runoff amounts of less than 38 mm and runoff curve numbers of less than 60. Additionally, the range of curve numbers should be small (say 20 percent) to reasonably conform with the assumption of homogeneity. The following steps outline the method. ( l) Determine the drainage area (A) in. square kilometers. (2) Determine the soil classification based on runoff potential (Type A ... B. C, or D) as described. in Section 5.7.5. One approach for a general classification is to determine the soil name and type from NRCS soil maps or reports. (3) Determine the antecedent soil moisture conditions (AMC) as discussed in Section 5.7.6. ( 4) Classify the hydro logic condition of the soil cover(good, fuir, or poor). Refer to the footnotes on Tables 5.7-1through5.7-4. ( 5) Lise Tables 5. 7-l through 5. 7-4 to determine the runoff curve nwnber (RCN) for the particular soil classitkation for an A.~C II. If appropriate, adjust for AMC I or AMC Ill using Equations 5 .7-5 and 5.7-6 respectively. If necessary, determine a weighted value by dividing the sum of the products of the subarea sizes and RCNs by the total area. This process is similar to the weighting of runoff coefficients in the Rational Method. However, the runoff factors are not directly related. ( 6) Estimate the watershed time of concentration in hours (TC). This may be petformed as outlined in Section 5 .5 or with reference to the description of time of concentration determination in Appendix 5-I of the Hydraulic Volume. Hvdraulic Desfrm 5-45 TrnnT-f)<J/Qf, 141011 02/12/03 WED 12:40 FAX 979 6900329 RME ~012 (7) Determine the potential maximum storage (S) using Equation 5.7-2. (8) Determine the initial abstraction (Ia) using Equation 5.7-3. These are the losses that occur · before runoff begins and include depression storage, interception and infiltration. If Ia is greater than P, it is possible that the rainfall event would not produce runoff (which would be unusual for design frequencies). The abstraction equation may need modification or an alternate means of estimating this value may be necessary, although no specific research has been performed to determine such adjusttnents. (9) Reference Figure 5.7-2 to determine the rainfall distribution type based on location of the watershed (Type II or Type ill for Texas). (lO)Based on the design frequency and a 24-hour duration storm, refer to the Appendix 5-2 to determine the total rainf alI (P) for the location of the watershed. (I !)Determine the accumulated direct runoff (R) using Equation 5.7-4. This value, when multiplied by the watershed area, will indicate the total volume of the rainfall that appears as runoff. (12)Refer to Equation 5.7-7 and Table 5.7-6 with the relevant distribution type from step 10 to determine the unit peak discharge (qu) using time of concentration (tc) and the ratio IJP. _ (l 0c,,-3.J6609) (T c,+c: ta,~) -7 -q" -. c ·········••••••••••·············•••••····.)· -I where: qu = unit peak discharge (m3/s/km2/mm) Tc = time of concentration (hrs) Table 5.7-6 -Coefficients for Equation 5.7-7 Rainfall Type I.IP 4 c, C: II 0.1 2.5532 -0.6151 -0.164 0.3 2.4653 -0.6226 -0.1166 0.35 2.419 -0.6159 -0.0882 0.4 2.3641 -0.5986 -0.0562 0.45 2.2924 -0.5701 -0.0228 0.5 2.2028 -0.516 -0.0126 m 0.1 2.4732 -0.5185 -0.1708 0.3 2.3963 -0.512 -0.1325 0.35 2.3548 -0.4974 -0.1199 0.4 2.3073 -0.4654 -0.1109 0.45 2.2488 -0.4131 -0.1151 0.5 2.1777 -0.368 -0.0953 ( 13 )With reference to Table 5.-: 7-7, detennine the pond adjustment factor (F). This adjustment is to account for pond or swamp areas within the watershed which do not interfere with the time of concentration flow path. 5-46 TxDOT-09196 02/~2(03 WED 12: 40 FAX 979 6900329:.... ------'RME=;..._------ Table 5.7-7: Ponding Adjustment Factor % Ponded/swamp area Factor (F 0 1 0.2 0.97 1 0.87 3 0.15 5 0.72 NOTE: This factor is not intended to replace a hydrograph routing technique where cpnsiderable detention storage is present (typically, with surface area of ponding in excess of 5% of the watershed area). ( 14)Compute the peak discharge (Q) from Equation 5.7-8. Q = quARF ..................................................... .5.7-8 where: Q = peak discharge (m\'s) qu = unit peak discharge (m3/s/k:m2/mm) from step 12 A = drainage area (km2) from step 1 R = runoff volume (IIUTl) from step 11 F = ponding factor from step 13 (15)Repeat steps 10 through 14 for other desired frequencies. A detailed description of this method appears in "Urban Hydrology for Small \Vatersheds," (TR-55). 5.7.8 NRCS Dimensionless Unit Hydrograph ln many instances. for highway drainage design. peak discharge methods v.111 suffice for runoff estimation. However, the estimation of runoff hydrographs may be occasionally necessary for situations such as detention pond design, reservoir routing, or channel routing, especially for larger areas and those in which watershed conditions cannot be considered homogeneous. Many hydrograph methods are available and not specifically excluded for use by the deparonent. However. the NRCS Dimensionless Hydrograph Method is incorporated here due to its relative ease of use as well as the relative ease with which variables can be determined. A unit hydrograph represents the time distribution of flow resulting from one millimeter of direct runoff occurring over the watershed in a specified time. The NRCS dimensionless unit hydrograph is plotted in terms of the ratio of rime over time to peak. A curvilinear dimensionless unit hydrograph is shown in Figure 5.7-3. For hand computations. a triangular hydrograph is considered reasonable as shown in Figure 5.7-4. Hvdrrmlir. ()p_r:frm 5-47 TxDOT-{)9/96 141013 02/12/03 WED 12:41 FAX 979 6900329 RME 141014 ... ' ~ Chapter 5--1-/ydro/ogy Appendix 5-2-24-Hour Rainfall Depth Countv 1-year 2-year 5-year 10-year 25-year 50-vear 100-year Anderson 89 112 152 178 213 241 267 Andrews 0 66 89 109 127 142 165 Angelina 97 122 165 196 234 267 292 Aransas 89 114 160 191 229 262 300 Archer 71 93 124 145 173 196 221 Annstron~ 58 71 97 117 135 150 170 Atascosa 0 102 140 170 198 224 254 Austin 81 118 161 197 231 264 300 lBailev 0 66 86 107 119 147 157 Bandera 0 97 132 157 188 211 239 Bastroo 81 107 145 173 203 229 257 Baylor 69 90 122 137 16& 191 213 Bee 86 108 152 180 216 241 279 Bell 79 104 140 170 198 224 251 !Bexar 0 97 135 165 198 221 251 !Blanco 0 97 135 165 . 193 218 246 :Borden 0 74 104 121 145 163 183 !Bosaue 79 102 137 165 191 216 241 !Bowie 91 112 146 174 199 224 250 Brazoria 99 130 178 216 254 292 330 Brazos 76 114 156 185 222 248 279 Brewster 51 66 86 109 127 145 165 [Briscoe 0 74 100 119 138 155 1-1 '~ Brooks 8 J 108 152 180 213 241 279 Bro....,11 71 94 130 155 180 206 231 Burleson 76 l 13 155 184 ,.,, ._ __ 245 278 Burnet 74 97 135 160 191 216 241 Caldwell 79 104 142 170 201 226 254 Calhoun 91 117 163 198 236 267 305 Cameron 89 117 160 188 229 254 292 Camo 90 112 147 174 202 226 251 Carson 56 71 94 114 132 147 168 Cass 91 113 147 174 201 226 251 Castro 0 67 91 109 124 140 160 Chambers 104 140 185 224 257 297 333 Cherokee 91 114 155 183 216 241 262 Childress 62 81 109 127 150 175 191 Clay 72 94 130 147 178 201 226 Cochran 0 65 86 107 121 135 157 Coke 66. 84 114 135 163 183 208 Coleman 71 91 127 147 175 198 226 CoUin 81 102 137 163 193 218 244 Collingsworth 61 79 107 124 147 170 185 Colorado 89 117 160 193 229 259 295 Comal 74 97 135 160 191 216 241 Co mane be 74 .• 97 132 l57 183 208 234 Concho 71 91 122 145 173 196 224 Cooke 79 97 132 157 185 203 236 Coryell 76 102 137 163 193 218 24.5 Hvdraulic Desivn '-711 r..,.rinT_..flO!OJ: DP-HARVEY HILLSIDE -(02-00100055) ENGINEERING REVIEW COMMENTS No. 1 1. Straighten out slope of line, remove joint marks and call out slope. 2. Please tie down profile by stationing flow lines at every slope change and at fittings. 3. Add blow off to low point at creek crossing. 4. At the creek crossing, why ductile iron pipe and encasement pipe? 5. Since you have a gate valve at the tie in to the existing line (Station 0+23), the gate valve and box at Station 3+17 is not necessary. Reviewed by: Carol Cotter Date: March 10, 2003 NOTE: Any changes made to the plans, that have not been requested by the City of College Station, must be explained in your next transmittal letter and "bubbled" on your plans. Any additional changes on these plans that have not been pointed out to the City of College Station will constitute a completely new review. Page 2 of 2 I -~ar 25 03 07:29a Rabon Metcalf Engineering 9796900329 FACSIMILE TRANSMITTAL SHEET TOo FROM: Mark Dudley Rabon Metcalf, P.E. COMl'ANY: DATE: RM Dudley Construction 3/25/03 FAX NUMBER: TOTAL NO. OF PAGES INCLUDING COVER: 776-2235 3 1'110!-lE Nt.:MBER: CC: Carroll Cotter RE: CC FAX NUMBER: Harvey Hillside Water Line 764-3496 0 URGENT 0 FOR REVIEW 0 PLEASE COMMENT 0 PLEASE REPLY li'.J FOR YOUR RECORDS NOTES/COMMENTS: The infunnation contained in this fax is confidential and is exclusively for the use of the previously addressed party. Please call the above number to correct any difficulties with the transmission of this fax. p. 1 • Mar 25 03 07:29a Rabon Metcalf Engineering 9796900329 p.2 EMAlL: R)l.1T:NG!NffR(~0.COM March 25 , 2003 Mark Dudley RM Dudley Construction 11370 State Highway 30 College Station, TX 77845 RE: Water Line Revision Design Notification Water Line Improvements -Block One, Lot 42, Harvey Hillside RME No. 121-0147 Dear Mr. Dudley: Please find attached the revised drawing for the water line route on the above referenced project. These changes resulted from the marked gas pipeline route, my meeting with you, and a separate meeting that I had with Mr. John Logan (COCS) yesterday. Due to the location of the existing sanitary sewer, gas pipeline, and available space between the two, we will have to cross the gas pipeline twice as shown. As required by Exxon-Mobile pipeline, our water line will need to cross under their pipe with a minimum of 24" clearance (outside of pipe to outside of pipe). Also, the joint of pipe crossing under the gas pipeline will need to be encased with a segment of pressure class pipe. Along with these changes, I will need the new elevations and grades for the water line installation crossing the creek, and south of the creek to the terminating fire hydrant. This information will be incorporated into the record drawings provided to Public Works. Please provide a copy of this information to Mr. Logan as representation of my authorization for the described changes. Please call should you have any questions or require assistance. Cc: Carroll Cotter CDl-12l-Ol47-L04 Page -I PR,lOSEO VARIABLE 'MOtH P.U.E. STA 3+92.67: 1-8" (MJ) 45" BEND (TWIST BEND TO BEGIN SHALLOWING OF LINE) I -a"xs· (MJ) TEE 2-6" (MJ) GATE VALVES & BOXES I -8"x6" (MJ) REDUCER 1-6" MJ PLUG I 0 L.F. OF EROSION CONTROL SILT FENCING, SEE DETAIL SHEET 2 INSTALLED AFTER BACKFILL OF TRENCH) PLAN ~IEYf'. SCALE: 1~40 \ 10 L.F. OF EROSION CONTROL SILT FENCING, SEE DETAIL SHEET 2 (INSTALLED AFTER BACKFILL OF TRENCH "' \ \ \ \ \ " STA 8+25.00: 1-6"•6' (MJ) TEE 1-FlRE HYDRANT (TYPE II) 2-6" (MJ) GA TE VALVES & BOXES 1-6" MJ PLUG 3. Qi , I\) (.11 0 w 0 .,,J w 0 Qj :;u Qj rr 0 :J :J: tD ~ () Qj ...... -t) l'Tl :J ""' ..... :J tD tD , ..... :J ""' (0 .,,J (0 en (0 0 0 w I\) (0 .,, . w ~-'1 DEVELOPMENT PERMIT PERMIT NO. 02-055 Project: Harvey Hillside Block 1 Lot 42 Waterline COLLlGl STATION FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE : CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: Harvey Hillside Lot 42, Block 1 DATE OF ISSUE: 03/12/03 OWNER: Mark Dudley 11370 SH 30 College Station, TX 77845 TYPE OF DEVELOPMENT: SPECIAL CONDITIONS: SITE ADDRESS: 3950 Harvey Road DRAINAGE BASIN: Carter's Creek VALID FOR 3 MONTHS CONTRACTOR: Waterline Construction Only All construction must be in compliance with the approved construction plans All trees must be barricaded, as shown on plans, prior to any construction. Any trees not barricaded will not count towards landscaping points. Barricades must be 1' per caliper inch of the tree diameter. Erosion control per the approved plans shall be installed for duration of project. 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. If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite, it is the contractors responsibility to implement measures that will meet City, State and Federal requirements. 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 as well as erosion, siltation or sedimentation resulting from the permitted work. 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 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. I Date ENGINEER'S COST ESTIMATE WATER LINE IMPROVEMENTS HARVEY IDLLSIDE BLOCK ONE, LOT 42 COLLEGE STATION, BRAZOS COUNTY, TEXAS NO. DESCRIPTION 1 Mobilization, Traffic Control, & Trench Safety 2 8" PVC (C900 -DR 14 -Class 200) Water Line wffype "B" Backfill 3 6" PVC (C900 -DR 14 -Class 200) Water Line wffype "B" Backfill 4 8" (MJ) Gate Valve & Box 5 6" (MJ) Gate Valve & Box 6 Ductile Iron Fittings (Class 350) 7 Standard Fire Hydrant (Type 2) & Appurtenances 8 15" Steel Encasement (Sch 40) w/8" DIP (Class 52) Carrier Pipe w/Locking Joints & Casing Spacers 9 12" Steel Encasement (Sch 40) w/6" DIP (Class 52) Carrier Pipe w/Locking Joints & Casing Spacers 10 Creek Crossing (Erosion Control Measures & Extra Compaction Effort) 11 Water Services 12 Silt Fencing QUANTITY UNIT 1 LS 365 LF 384 LF 2 EA 4 EA 1 LS 1 EA 40 LF 20 LF 1 LS 1 EA 100 LF UNIT COST $1,586.25 $17.75 $15.00 $700.00 $525.00 $3,000.00 $2,150.00 $85.00 $70.00 $1 ,500.00 $375.00 $5.00 SUB-TOTAL = This Engineer's Cost Estimate was prepared in this office, at the date shown, nd is released for the purpose of CD1-121-0147-E04 Date RABON .METCALF ENGINEERING POST OFFICE BOX 9253 COILEGE STATION. TEXAS T/842 CELL: (979) 219-4174 FAX: (979) 690-0329 E-MAIL: RMENGINEER@JUNO.COM TOTAL COST $1 ,586.25 $6,478.75 $5,760.00 $1 ,400.00 $2,100.00 $3,000.00 $2, 150.00 $3,400.00 $1 ,400.00 $1 ,500.00 $375.00 $500.00 $29,650.00 1 of 1 ENGINEER'S COST ESTIMATE WATER LINE IMPROVEMENTS HARVEY HILLSIDE BLOCK ONE, LOT 42 COLLEGE STATION, BRAZOS COUNTY, TEXAS NO. DESCRIPTION QUANTITY UNIT 1 Mobilization, Traffic Control, & Trench Safety 1 LS 2 8" PVC (C900-DR 14-Class 200) Water Line 365 LF wffype "B" Backfill 3 6" PVC (C900 -DR 14-Class 200) Water Line 384 LF wffype "B" Backfill 4 8" (MJ) Gate Valve & Box 1 EA 5 6" (MJ) Gate Valve & Box 4 EA 6 Ductile Iron Fittings (Class 350) 1 LS 7 Standard Fire Hydrant (Type 2) & Appurtenances 1 EA 8 2" Blow-Off Valve 1 EA 9 15" Steel Encasement (Sch 40) w/8" DIP (Class 52) 40 LF Carrier Pipe w/Locking Joints & Casing Spacers 10 12" Steel Encasement (Sch 40) w/6" DIP (Class 52) 20 LF Carrier Pipe w/Locking Joints & Casing Spacers 11 Creek Crossing (Erosion Control Measures & Extra 1 LS Compaction Effort) 12 Water Service 1 EA 13 Silt Fencing 100 LF This Engineer's Cost Estimate was prepared in this office, at the date sho and is released for the purpose of CD1-121-0147-E05 RABON METCALF ENGINEERING POST OFFICE BOX 9253 COLLEGE STATION. TEXAS 77842 CELL: 1979) 219-4174 FAX: 19791 690-0329 E-MAIL: RMENGINEER@JUNO.COM UNIT COST $1,586.25 $17.75 $15.00 $700.00 $525.00 $3,000.00 $2,150.00 $450.00 $85.00 $70.00 $1,500.00 $375.00 $5.00 SUB-TOTAL= TOTAL COST $1,586.25 $6,478.75 $5,760.00 $700.00 $2,100.00 $3,000.00 $2,150.00 $450.00 $3,400.00 $1,400.00 $1 ,500.00 $375.00 $500.00 $29,400.00 1 of 1 DP-HARVEY HILLSIDE -(02-00100055) ENGINEERING REVIEW COMMENTS No. 1 1. You will need to show grade control on the water line by stationing flow lines at slope changes and at fittings. In the current configuration you will also need a blow off at the lowest point of the dip in the pipe (Sta 2+02). Straightening the line will simplify the amount of information and remove requirement of blow off. 2. Remove joint marks and call out slope. 3. Add blow off to low point at creek crossing. Blow off positioned at lowest point. You can tee into line and slope blow off to point out of creek and then turn up. 4. Since you have a gate valve at the tie in to the existing line (Station 0+23), the gate valve and box at Station 3+17 is not necessary. Reviewed by: Carol Cotter Date: March 10, 2003 NOTE: Any changes made to the plans, that have not been requested by the City of College Station, must be explained in your next transmittal letter and "bubbled" on your plans. Any additional changes on these plans that have not been pointed out to the City of College Station will constitute a completely new review. Page 2 of 2 The City of College Station, Texas P.O. Box 9960 January 21, 2003 Mark Dudley 11370 State Highway 30 College Station, TX 77845 Embracing the Past, Exploring the Future. • 1101 Texas A venue • College Station, TX 77842 www.ci.college-station.tx.us RE: NOTICE OF NON-COMPLIANCE with Chapter 13, City of Co ge Station Code of Ordinances Lot 42, Block 1, Harvey Hillside (Harvey Road at Pamela Lane) Mr. Dudley: • (979) 764-3500 City Inspectors have observed that fill is being brought onto and being placed on the above referenced site contrary to the Development Permit currently active. The current Development Permit is for clearing and grubbing only, and does not allow or provide for fill or importation of material. The importation and placement of fill must cease immediately until the Development Permit is ammended to allow for such placement. Erosion fencing must be placed around the material already on site, and any areas where the ground cover has been disturbed by the importation or fill process. You may submit application information to allow fill along with supporting information to show that the fill will not be detrimental to the creek and/or neighboring properties. If Staff determines that the material has impacted the flood carrying capacity of the creek, or may cause significant erosion or siltation problems, the material may be required to be removed. Failure to comply with these actions will result in enforcement action taken in accordance with Chapter 13, Section 7 of the Code of Ordinances. If you have any questions about these requirements, please call me at (979) 764-3570. Thank you for your cooperation. s7~ et ~Mzy~E Assistant City Engineer xc: Kelly Templin Jon Mies Carol Cotter Natalie Ruiz o:\group\dev _serv\Tom V\DuddleyDesist Home of Texas A&M University The Ci!f of College Station, Texas racing the Past, Exploring the Future. P.O. Box 9960 • College Station, TX 77842 www.ci.college-station.tx.us January 21, 2003 RE: NOTICE OF NON-COMPLIANCE with Chapter 13, City of College Station Code of Ordinances Lot 42, Block 1, Harvey Hillside (Harvey Road at Pamela Lane) Mr. Dudley: • (979) 764-3500 City Inspectors have observed that fill is being brought onto and being placed on the above referenced site contrary to the Development Permit currently active. The current Development Permit is for clearing and grubbing only, and does not allow or provide for fill or importation of material. The importation and placement of fill must cease immediately until the Development Permit is ammended to allow for such placement. Erosion fencing must be placed around the material already on site, and any areas where the ground cover has been disturbed by the importation or fill process. You may submit application information to allow fill along with supporting information to show that the fill will not be detrimental to the creek and/or neighboring properties. If Staff determines that the material has impacted the flood carrying capacity of the creek, or may cause significant erosion or siltation problems, the material may be required to be removed. Failure to comply with these actions will result in enforcement action taken in accordance with Chapter 13, Section 7 of the Code of Ordinances. If you have any questions about these requirements, please call me at (979) 764-3570. Thank you for your cooperation. g;,~ B'f{Mzy~E~ Assistant City Engineer xc: Kelly Templin Jon Mies Carol Cotter Natalie Ruiz o:\group\dev _serv\Tom V\DuddleyDesist Home of Texas A&M University The Ci!f of College Station, Texas P.O. Box 9960 January 2, 2003 Mark Dudley 11370 State Highway 30 College Station, TX 77845 • Embracing the Past, Exploring the Future. 1101 Texas Avenue • College Station, TX 77842 www.ci.college-station.tx.us RE: NOTICE OF NON-COMPLIANCE with Chapter 13, City of College Station Code of Ordinances Lot 42, Block 1, Harvey Hillside (Harvey Road at Pamela Lane) Mr. Dudley: • (979) 764-3500 It has come to our attention that clearing and/or grading on the above referenced site is being performed without a Development Permit. Chapter 13 , Section 3 of the City of College Station Code of Ordinances requires a Development Permit prior to any clearing or development within the City of College Station. You may also be in violation of Texas Commission on Environmental Quality (TCEQ), Environmental Protection Agency (EPA), and Corp of Engineers regulations. In order to continue clearing your site, a Clearing and Grading Development Permit must be obtained by satisfying specific requirements. The submittal requirements necessary for a Clearing and Grading permit are as follows: a completed application; $200 application fee; a Notice of Intent (NOI); a Clearing/Grading Plan (showing existing and proposed elevations); and, an Erosion Control Plan. The items listed above shall be submitted within ten (10) working days of receipt of this notice. No construction work will be permitted until the site is brought into compliance. Failure to comply with this City Ordinance will result in enforcement action taken in accordance with Chapter 13 , Section 7 of the Code of Ordinances. If you have any questions, please call me at (979) 764-3570. Thank you for your cooperation. 7/lttl Brett Mccully, P.E. Asst. City Engineer xc: Natalie Ruiz, Development Coordinator Jon Mies, Fire Marshall O:\DEVE_SER\DEVPERM\NonComp\NON\DuddleyDesist.doc Home of Texas A&M University Brett, I received the comments on Mark's project the other day. Also, Carol, Spencer and I had a meeting prior to discuss some of the issues. I can address all of the comments, but I would like a little direction of the first comments about the floodway and variance. I have reviewed Chapter 13 and do not think a variance is required. Section 5-G "Special Provisions for Floodways" does sight that improvements within the flood way are prohibited, but a variance can be issued if it is demonstrated that no adverse conditions are created. Section 5-B establishes "Areas of Special Flood Hazard". Here it states that the floodway shall be determined by the most current FIS study and FIRM's. Since Mark's property is not mapped as having floodplain or floodway across it, by FEMA, does it technically by ordinance require a variance for these drainage improvements? This is just something new to me and I am trying to figure it out. If I am missing something, please point me in the right direction. The only other occurrence that I have to base this off of is the Callaway House. It was developed quite a while ago, may be we got away with something that we should have not, but we channelized a creek into a 8'x5' box culvert without any variance. Thanks for the help. I will be making the other changes and turning them in within a week or so. P.S. -Final go the joint letter for the Peace Lutheran TxDOT driveway permit. Do you mind if I submit the document to both COCS and TxDOT at the same time, or does it need to be routed through COCS? Rabon A. Metcalf, P .E. Rabon Metcalf Engineering P.O. Box 9253 College Station, TX 77842 Hm/Fx: (979) 690-0329 Cell: (979) 219-4174 Sign Up for Juno Platinum Internet Access Today Only $9.95 per month! Visit www.juno.com Page 1 of 1 file://C:\Documents%20and%20Settings\bmccully\Local %20Settings\ Temp\GW} 00004.H... 1110/2003 ~Carol Cotter -,SN£B.QACHMENI:99~ .. ENCROACHMENT -means an intrusion, obstruction, or other infringement on an area reserved for a specific purpose such as an easement or floodway. FLOODW A Y -means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot. AREA OF SPECIAL FLOOD HAZARD -is the land adjacent to a clearly defined channel within a community subject to a one percent or greater chance of flooding in any given year. The area may be designated as Zone A on the Flood Hazard Boundary Map (FHBM). After detailed ratemaking has been completed in preparation for publication of the FIRM, Zone A usually is refined into Zones A, AE, AH, AO, Al-99, VO, Vl-30, VE, or V. ESTABLISHMENT OF AREAS OF SPECIAL FLOOD HAZARD The basis for identification of the Areas of Special Flood Hazard shall be the most current engineering re-port entitled "Flood Insurance Study for the City of College Station, Texas" as accepted by FEMA and the Federal Insurance Administration, including the accompanying Flood Insurance Rate Maps and Flood Hazard Boundary Maps showing the floodway. The current report is dated January 2, 1981; however, any revisions, amendments, or updated studies accepted by FEMA and the Flood Insurance Administration shall be adopted by ref-erence and are hereby declared to be a part of this chapter. The most current Flood Insurance Study shall be used for all determinations of flood insurance rates, flood ways, and additional revisions as they become available. The current Flood Insurance Study, FIRM, FHBM, along with any revisions or amendments shall be maintained and made available by the designated Administrator of the Stormwater Management Program. SPECIAL PROVISIONS FOR FLOOD WAYS Located within Areas of Special Flood Hazard established in Section 5-B are areas designated as floodways. The flood way is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and the potential for erosion; therefore, the following provisions shall be required: (1) Encroachments shall be prohibited, including fill, new construction, substantial improvements of existing construction, structures, manufactured homes, or other development. Variances requested on this standard shall be accompanied by a complete engineering report fully demonstrating that the encroachments shall not result in any increase in water surface elevation or flood hazard upstream, within, or downstream of the encroachment location. The engineering report shall conform to the requirements of the Drainage Policy and Design Standards and shall bear the dated seal and signature of a registered professional engineer; (Ordinance No. 1728 of October 22, 1987) (2) Exemptions for the requirements of Section 5-G may be made in the following cases: (a) Customary and incidental routine grounds maintenance, landscaping and home gardening wh ich does not require a building permit, zone change request, or variance from the provisions of the Zoning Ordinance; (b) Emergency repairs ofa temporary nature made on public or private property which are deemed necessary for the preservation of life, health, or property, and which are made under such circumstances where it would be impossible or impracticable to obtain a development permit. (c) Temporary excavation for the purpose of maintaining, or repairing any public street, public utility facility, or any service lines related thereto; (Ordinance No. 1740 of February 25, 1988) (3) All new construction or substantial improvements of existing construction shall be subject to the methods of flood hazard reduction outlined in Section 5. (Ordinance No. 1728 of October 22, 1987) (4) When a regulatory floodway has not been designated, no new construction, substantial improvements, or other development, including fill, shall be permitted within zones designated Al-A30 and AE on the community's FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community. (Ordinance No. 1740 of February 25, 1988) Page 1 I Brett McCully -Mark Dudley 776-2135 for Brett From: To: Date: Subject: Pf' Deborah Grace Cotter, Carol; Thompson, Spencer 1n103 10:11AM Mark Dudley 776-2135 for Brett Page 1 The Ci!f of College Station, Texas P.O. Box 9960 January 2, 2003 Mark Dudley 11370 State Highway 30 College Station, TX 77845 • Embracing the Past, Exploring the Future. 1101 Texas Avenue • College Station, TX 77842 www.ci.college-station.tx.us RE: NOTICE OF NON-COMPLIANCE with Chapter 13, City of College Station Code of Ordinances Lot 42, Block 1, Harvey Hillside (Harvey Road at Pamela Lane) Mr. Dudley: • (979) 764-3500 It has come to our attention that clearing and/or grading on the above referenced site is being performed without a Development Permit. Chapter 13, Section 3 of the City of College Station Code of Ordinances requires a Development Permit prior to any clearing or development within the City of College Station. You may also be in violation of Texas Commission on Environmental Quality (TCEQ), Environmental Protection Agency (EPA), and Corp of Engineers regulations. In order to continue clearing your site, a Clearing and Grading Development Permit must be obtained by satisfying specific requirements. The submittal requirements necessary for a Clearing and Grading permit are as follows: a completed application; $200 application fee; a Notice of Intent (NOI); a Clearing/Grading Plan (showing existing and proposed elevations); and, an Erosion Control Plan. The items listed above shall be submitted within ten (10) working days of receipt of this notice. No construction work will be permitted until the site is brought into compliance. Failure to comply with this City Ordinance will result in enforcement action taken in accordance with Chapter 13, Section 7 of the Code of Ordinances. If you have any questions, please call me at (979) 764-3570. Thank you for your cooperation. 7littl Brett McCully, P .E. Asst. City Engineer xc: Natalie Ruiz, Development Coordinator Jon Mies, Fire Marshall O:\DEVE_SER\DEVPERM\NonComp\NON\DuddleyDesist.doc Home of Texas A&M University STAFF REVIEW COMMENTS NO. 1 Project: DP-HARVEY HILLSIDE-DEVELOPMENT PERMIT{ 02-00100055) ENGINEERING 1. It appears that this project proposes to relocate the stream and fill in the floodway. Encroachment into a floodway is prohibited by the Ordinance. You will need to obtain a variance to the drainage ordinance to proceed with this proposal. 2. Show inlets to the storm water line, addressing surface flow down the west side of Pamela Lane with an inlet at the manhole. 3. Recheck delineation of drainage basins for accuracy. 4. Elaborate on how the connection of the proposed junction box to existing headwall is to be made. 5. The flood plain administrator does not feel that Condition I accurately reflects the hydrologic conditions of the watersheds. Please revise. 6. Because this development is greater than 5-acres, an NOi is required. 7. Provide electronic copy of HEC-RAS model and data. Provide map with cross sections. 8. There appear to be two culverts labeled #1 in HEC-RAS table. Verify. Reviewed by: Carol Cotter Date: December 30, 2002 NOTE: Any changes made to the plans, that have not been requested by the City of College Station, must be explained in your next transmittal letter and "bubbled" on your plans. Any additional changes on these plans that have not been pointed out to the City, will constitute a completely new review. Staff Review Comments Page 2 of 4 l * ~ Notice of Proposed Installation •-Utility Line on Non-Controlled Access Highway ·~ form 1023 (Rev. ~93) (Pre11£0~1'erslon(S} ate Q~ To the Texas Transportation CommiuiOll c/o District Engineer Texas Department of Transportation Teras ~-~~~-~~-~ Date :fANVAf2.'1 IS\ -zoo~ Formal notice is hereby given that ~ .m · t>~o\.E-'"\ C~a.<JC--tt ~N Co111PB»Y N!>lm9$ to place a 8 u VJA""l~ "'"'''ra 3°\'E. -\ N line within the right-of.way of ?·". 'Oc in __ _Jf0=-='2A=...:;'Z;~o.-i!l!~~~------County, -77- Texas as follows: (give loc:atiOU; length, general design. etc.) lle.-\N '70 8.\t:n\Ner gn WhtF-£ L-1"1\:._ ~t'i!.cY.. ~(pt> /.. ...... WES1' OF -rH€ 1N-Ce..·wt:5€c110l...l OF ~-H-~l::> ct'\ ~6\.A ~J'JE. J0EJl'J~ tr-l ~u-m-'2\&rtlrl-O~-wf'.~ o F ~.H. ~ The line will be co:.nstruct.ed and maintained on the highway right-ol·way as showu on the attaclled drawing and fn a~e with ~ .n.dtiB, regu.ladons atid policies of the Tens Depariltint of Tranaportation (TxOOT), and all gown-n:ing laws, includiug but; not limited io the "'Federal Clean Water Act, .. the -~·Federal Endangered Species Act," and the "Federal Historic Preservation Act." Upan request by TIDOT, proof a[ compliaace with all goven:WJg laws,rul#, W ~mtj!f~ will ht!.$11hml~~ 'rt'DQT ~~ ~mrnencement ofCOlJBtructlJ:m. 'fhe location and description ot"t.be proposed line and appmtenancea i1 more fully shoWD by __ :i ...... ""' ____ complet.e seta of di·awinis ·attached to t.hfs notice. Construction of this line will begin on or after the ,_. _l __ day of fi;:e,aA A~_.± By .signing below., 1 t:.ertify tht 1 am authorized to l"flpresent the Firm listed below, and that the Firm agrees to the conditionslprov.:isions mdudedln thfs ~t-t Firm .12.·m. ~~ ~~""t~Vl"'l\a~ = By(Prfntj-LN\~·~· l!;t!::~~~'!tl-.J.__,,..,......~~~--~~ 8ignature -JC.-,~~--'~~ ...... ....6o~::.._~~~~----~ Title 1 Address I 1$'7c !:>. H . ?;2C) C.0\..\...E.<:ie. 57Alt~, \)( 77845 P.boneNo. l<17'tj 771.P-Zl'5fii Form 1023 (Rev. 09-93) (Previous Versions Obsolete) .. APPROVAL Hwy.No . ..._~~-~------,~~~~~--~~~ Bel!.. RM Offset EndRM Offset Matntenance SectiOn No-.---·---~-.......... - ==_,.-...,...----~··-. -. Date The Texas Department of Transportation (TxD01) o~~rs no objection ~o the location. on the right-Of-way of your proposed ______________ line as shown by accompanying drawings and notice dated except as noted below. It is e..~pressly ·understood that the TxDOT docs not purport, hereby, to grant any right, claim, title., or e~ment in or upon this highway! and it is !W'lher understood that tb.e TxDOT may require tbe owner fl> relocate this line, subject to provWons of govern;ng Jaws. by gMng rhirty (30} days written. notice.. "You are req.ues.tc.d ro notify this oftire poor· ro rommcmcement ot \i.fl.Y rou.f.i.ne. of periodic maintenance which re.quires pruning ot: trees within the .hig..bway ri,g.h1-0f-way, so Iha! we may p1pvide specifications for the ~nt .and methods 1:0 govern .in trimming, topping. tree balance~ type _ of curs,_ painting c..uts and-clean up. These spe.cificalions are intended to preserve-our considerable investment in highway planting and beautification, by reducing damage due to trimming. The instaJJa.tion sb.aJJ.not damage any part of the-highway and adequate. provisions mYst be made to cause minimum. inconveniences lO traffic and adjacent property owners. Jn the event the Owner fails to comply with. any or aU of the requirements as set forth herein. the State may cake such ~ction as it deems appropriate to compel compliance.. • General Special Provisions: .. \ • Revegeta.tion Spednl Provisions: In order to minimiz.e erosion and sedimentation resulting from the proposed installation, the project area will be revegetated . · .· ' . .. . · 0 in accordance ~th TxDOrs Standard Specification Item ··164 -which specifies the appropriate grass seed mix 10 be used, or 0 as indicated on the auachment. Please notify _________________________ torty-eight (48) hours prior to starting constr"'ction of the line in order that we may have a representative present Texas Department of Transportation By:_··----.;_~--------'----'-----District Engineer--District No .. _____ _ December 9, 2002 Brett McCully, P.E. Assistant City Engineer City of College Station 1101 Texas Avenue South College Station, TX 77842 RE: R.M Dudley Construction -Storm Sewer Improvements Block One, Lot 42, Harvey Hillside RME No. 121-0137 DearBrett: Please find attached the following findings, calculations and attachments for the above referenced project's storm sewer improvements. This drainage letter and the supporting design methods were performed in accordance with the City of College Station's Drainage Design Policies and Standards. Information used for the design and the resulting calculations, for the storm sewer improvements, are as follows: •!• A-1: Drainage Area Map •!• A-2, 3 & 4: TR-55 -Hydrology Models; •!• A-5 & 6: HEC-RAS Summary Tables; •!• A-7: Storm Sewer Improvements-Construction Plan Hydrology The project site is located within the watershed of Carters Creek. Runoff is conveyed to the site from two separate watersheds by two unnamed watersheds. These watersheds and their associated tributaries were named Tributary A & B for the purposes of this study. Tributary A is will be the creek experiencing the drainage improvements. This information is further clarified on the Drainage Area Map (A-1). In general, Tributary A conveys runoff in a north to south manner, bisecting Lot 42, and discharging into Tributary B. This watershed is approximately 43 acres in land area. From the confluence of Tributary A the watershed for Tributary B extends upstream in a northwest direction and comprises a total area of approximately 238 acres. Using Technical Report 55 (TR 55) hydrology modeling methods the two watershed's runoff values were determined. Based on the above average hydro logic conditions of these watersheds, Antecedent Moisture Condition I was selected. Results from the I, 2, 5, 10, 25, 50 & 100-year rainfall events are illustrated the TR 55 data sheets (A-2 thru 4) for each respective watershed. Filename: CDl-121-0137-LOl Page - 1 ' Watershed "C" is the combined watershed of both Tributary A & B which will be used for downstream water surface calculations and modeling for the storm sewer improvements. Hydraulic Once the required hydrologic calculations were completed then the storm sewer improvements could be modeled and sizing of the drainage structure could be accomplished. The hydraulic modeling of the storm sewer improvements were utilized using the HEC-RAS program. Modeling coefficients and parameters for the proposed improvements where input as follows: •!• Tributary B was modeled immediately downstream of the proposed storm sewer improvements. This starting water surface elevation (WSE) was determined by normal depth calculations. From this information the model determined whether the storm sewer was under inlet or outlet control; •!• Coefficients of friction for the existing CMP were set to 0.025 and the proposed RCP at 0. 013 . Within the proposed junction box, the coefficient of friction was increased to 0. 020 to account for head losses; Based from this model the following findings were determined. The proposed drainage improvements were designed for the 25-year rainfall event and analyzed during the 100-year rainfall event. •!• During the design storm, the proposed 48" RCP would discharge runoff into Tributary B at a rate of 5.57 fps. Rock rip-rap was added to the outlet structure to reduce the discharge velocity further and to help control erosion of the creek (A-5 & 6); •!• During the 100-year rainfall event, the capacity of the storm sewer system is exceeded. The headwater elevation at the 48" CMP reaches an elevation above the lowest grade of Pamela Lane and approximately 45 cfs is discharged of the road. This occurs near the intersection of S.H. 30 (A-5 & 6); •!• The storm sewer improvements will, in general, constitute 184 feet of 48" RCP, outlet end treatment for channel stabilization and a concrete junction box at the connection point to the 48" CMP; The attached engineering calculations are issued for the before stated drainage improvements and are issued by me and are applicable to this project. Please call should you have any questions are require assistance. Filename: CDl-121-0137-LOl Page -2 Drainage Area 11A11 TR 55 -HYDROLOGY MODEL (R) = ___ (_P_-_o_.2_S ..... )2 ___ Equation 5.7-4 (P +0.8S) 1 NRCS RAINFALL-RUNOFF EQUATION (R): R 1 R2 Rs R 10 R 25 R 50 R 100 CONDITION (I) 3.83 16.38 36.96 54.06 78.37 96.n 119.84 0.15 0.64 1.46 2.13 3.09 3.81 4.72 CONDITION (III) 42.34 76.36 115.83 143.65 179.54 204.93 235.34 1.67 3.01 4.56 5.66 7.07 8.07 9.27 AVERAGE 17.64 41 .68 73.30 96.99 128.66 151.62 179.55 0.69 1.64 2.89 3.82 5.07 5.97 7.07 1a P =accumulated rainfall (potential maximum runoff) (mm)-Appendix 5-2 -24 Hour Rainfall Depth P1 P 2 p5 p 10 p 25 p 50 p 100 76 114 156 185 222 248 279 2.99 4.49 6.14 7.28 8.74 9.76· 10.98 1b S =potential maximum retention (mm) (S) = 25400 -254 RCN (S)ro = 223.68 mm (S)cm> = 40.85 mm (S)(AVG) = 110.63 mm therefore {18) = initial abstraction (mm) Oa> = 0.2S (la)(l) = 44.74 mm {la)(IIJ) = 8.17 mm Oa)AvG = 22.13 mm 1c RCN =runoff curve number-Table 5.7-1 (Urban Areas) & Table 5.7-2&3 (Agircultural Land) dry soil conditions (antecedent moisture condition I) 4.2RCN(Il) RCN(I) = 10 -0.058RCN(II) mm in mm in mm in mm in Equation 5 7-2 Equation 5 7-3 Equation 5.7-5 wet soil conditions (antecedent moisture condition III) 23RCN(II) RCN(III) =-----~---Equation 5 7-6 10 + 0.13RCN(II) RCN Table Input Data Soil Classification Type = c RCN(I) = 53.17 Hydrologic Condition = Fair RCN(III) = 86.15 RCN(II) = 73 RCNAVG = 69.66 121--0137 TR 55 Method Drainage Area "A" TR 55 -HYDROLOGY MODEL 2 NRCS GRAPHICAL PEAK DISCHARGE (Q): (Q) = quARF Q1 Q2 Qs 0 0 1 3 15 33 1 2 3 38 69 104 0 1 2 16 37 66 Watershed Input Data Drainage Area = 0.067 Drainage Area = 0.17 Ponding Factor= 1 Q10 CONDITION (I 1 49 CONDITION (III) 4 129 AVERAGE mi2 km2 2 87 Q25 Qso 2 2 70 87 5 5 161 184 3 4 116 136 Table 5.7-7: Ponding Adjustment Factor Q100 3 108 6 211 5 161 Equation 5. 7-8 m3/sec ft3Jsec m3/sec tt3/sec 2a qu =Unit peak discharge (m3/s/km2/mm) (qu) = 1o<c.-3.36609) * Tc(C,+c, x tog TJ Equation 5 7-7 (qu) = 0.147 m3/s/km2/mm Table 5.7-6 Coefficient Data Rainfall Type = III Figure 5.7-2 : Rainfall Distribution Types in Texas IJP(l)= 2.05 IJP(IIJ) = 0.37 IJP(AVG) = 1.01 !JP Used= 0.30 Co= 2.3963 c, = -0.512 C2 = -0.1325 2b T0 =Time of Concentraction (hrs) 0.516 hrs Length (L) VelocityM TIME (T) (ft) (fps) (sec) 1,233 4.25 290 1, 117 2.25 496 590 0.55 1,073 TOTAL (L) AVG (V) TOTAL (T) 2,940 1.6 1,859 121-0137 TR 55 Method Drainage Area "B" TR 55 -HYDROLOGY MODEL (R) = __ __.(_P_-_o._2S ...... )._2 ___ Equation 5 7-4 (P +0.8$) 1 NRCS RAINFALL-RUNOFF EQUATION (R): R1 R2 R5 R 10 R 25 R 50 R 100 CONDITION (I) 5.37 19.72 42.18 60.45 86.12 105.39 129.40 0.21 0.78 1.66 2.38 3.39 4.15 5.09 CONDITION (III) 44.68 79.27 119.13 147.15 183.22 208.71 239.22 1.76 3.12 4.69 5.79 7.21 8.22 9.42 AVERAGE 19.85 45.16 77.87 102.17 134.48 157.82 186.14 0.78 1.78 3.07 4.02 5.29 6.21 7.33 1a P = accumulated rainfall (potential maximum runoff) (mm) -Appendix 5-2 -24 Hour Rainfall Depth p 1 P 2 p5 p 10 p 25 p 50 p 100 76 114 156 185 222 248 279 2.99 4.49 6.14 7.28 8.74 9.76 10.98 1b S =potential maximum retention (mm) ($) = 25400 -254 RCN (S)ro = 201 .59 mm (S)(lu) = 36.81 mm (S)(AVG) = 101.01 mm therefore (111) = initial abstraction (mm) (la)= 0.2S (la)(!)= 40.32 mm (la}(III) = 7.36 mm (la)AVG = 20.20 mm 1c RCN =runoff curve number-Table 5.7-1 (Urban Areas) & Table 5.7-2&3 (Agircultural Land) dry soil conditions (antecedent moisture condition I) 4.2RCN(II) RCN(I) = 10 - 0.058RCN(II) mm n i mm n i mm n i mm in Equation 5 7-2 Equation 5 7-3 Equation 5. 7-5 wet soil conditions (antecedent moisture condition III) 23RCN(II) RCN(III) =---------Equation 5 7-6 10 + 0.13RCN(II) RCN Table Input Data Soil Classification Type = c RCN(I) = 55. 75 Hydrologic Condition = Fair RCN(III) = 87.34 RCN(II) = 75 RCNAVG = 71 .55 121-0137 TR 55 Method Drainage Area "B" TR 55 -HYDROLOGY MODEL 2 NRCS GRAPHICAL PEAK DISCHARGE (Q): (0) = quARF 01 0 2 Os 1 2 5 22 80 171 5 9 14 181 322 484 2 5 9 81 183 316 Watershed Input Data Drainage Area = 0.372 Drainage Area = 0.96 Ponding Factor = 1 010 CONDITION {I} 7 246 CONDITION (III} 17 598 AVERAGE mi2 km2 12 415 025 Oso 10 12 350 428 21 24 744 848 15 18 546 641 Table 5.7-7: Ponding Adjustment Factor Equation 5 7-8 0100 15 526 28 972 21 756 2a qu =Unit peak dischatge (m3/s/km2/mm) (qu}= 1o<c.-3.36609)•Tccc,+e2X1ogTJ Equallon57-7 (qu} = 0.119 m3/s/km2/mm Table 5.7-6 Coefficient Data Rainfall Type = III Figure 5.7-2: Rainfall Distribution Types in Texas IJP(I)= 1.85 IJP(Im = 0.34 IJP(AVG) = 0.93 IJP Used= 0.30 Co= 2.3963 C1= -0.512 C2 = -0.1325 2b Te= Time of Concentraction (hrs} 0.806 hrs Length (L) Velocity (V} TIME (T} (ft} (fps) (sec} 2,441 4.25 574 1,189 2.25 528 900 0.5 1,800 TOTAL (L) AVGM TOTAL (T) 4,530 1.6 2,903 121-0137 TR 55 Method Drainage Area "C" TR 55 -HYDROLOGY MODEL (R) = __ .-..l(.;...P_-...;.0;.;;;.2...;.S1....)2 ___ Equation 5.7-4 (P +0.8S) 1 NRCS RAINFALL-RUNOFF EQUATION (R}: R 1 R2 R5 R 10 R 25 R 50 R 100 CONDITION (I) 5.37 19.72 42.18 60.45 86.12 105.39 129.40 0.21 0.78 1.66 2.38 3.39 4.15 5.09 CONDITION (III) 44.68 79.27 119.13 147.15 183.22 208.71 239.22 1.76 3.12 4.69 5.79 7.21 8.22 9.42 AVERAGE 19.85 45.16 77.87 102.17 134.48 157.82 186.14 0.78 1.78 3.07 4.02 5.29 6.21 7.33 1a P =accumulated rainfall (potential maximum runoff) (mm) -Appendix 5-2 -24 Hour Rainfall Depth p 1 P2 P5 p 10 P25 p 50 p 100 76 114 156 185 222 248 279 2.99 4.49 6.14 7.28 8.74 9.76 10.98 1b S =potential maximum retention (mm) ($) = 25400 -254 RCN (S)m = 201 .59 mm (S)(IIl) = 36.81 mm (S)(AVG) = 101.01 mm therefore (18) =initial abstraction (mm) Cla} = 0.2S (la)(l) = 40.32 mm Cla)(nl) = 7.36 mm (la)AVG: 20.20 mm 1c RCN =runoff curve number-Table 5.7-1 (Urban Areas) & Table 5.7-2&3 (Agircultural Land) dry soil conditions (antecedent moisture condition I) 4.2RCN(II) RCN(I) = 10 -0.058RCN(II) - mm in mm in mm in mm in Equation 5 7-2 Equation 5 7-3 Equation 5 7-5 wet soil conditions (antecedent moisture condition III) 23RCN(II) RCN(III) =-----...;....;.._--Equation 5 7-6 10 + 0.13RCN(II) RCN Table Input Data Soil Classification Type = c RCN(I) = 55. 75 Hydrologic Condition = Fair RCN(III) = 87.34 RCN(II} = 75 RCNAVG = 71.55 121-0137 TR 55 Method Drainage Area "C" TR 55 -HYDROLOGY MODEL 2 NRCS GRAPHICAL PEAK DISCHARGE (Q): (Q) = quARF Q1 Q2 Qs 1 3 6 26 95 202 6 11 16 214 380 571 3 6 11 95 216 373 Watershed Input Data Drainage Area = 0.439 Drainage Area = 1.14 Ponding Factor= 1 Q10 CONDITION (I) 8 290 CONDITION (III) 20 705 AVERAGE mi2 km2 14 490 Q25 Qso 12 14 413 505 25 28 878 1000 18 21 645 756 Table 5.7-7: Ponding Adjustment Factor Equation 5 7-8 Q100 18 620 32 1147 25 892 2a qu = Unit peak discharge (m3/s/km2/mm) (qu) = 1o<c. -3.36609) • Tc(c,+e, x log TJ Equation 5 7-7 (qu) = 0.119 m3/slkm2/mm Table 5.7-8 Coefficient Data Rainfall Type = III Figure 5.7-2 : Rainfall Distribution Types in Texas IJPro = 1.85 IJP(IIJ) = 0.34 IJP(AVG) = 0.93 IJP Used = 0.30 Co= 2.3963 C1 = -0.512 C2= -0.1325 2b Tc= Time of Concentraction (hrs) 0.806 hrs Length (L) Velocity (V) TIME (D (ft) (fps) (sec) 2,441 4.25 574 1,189 2.25 528 900 0.5 1,800 TOTAL (L) AVG (V) TOTAL (T) 4,530 1.6 2,903 121-0137 TR 55 Method HEC-RAS Plan: PROP1 River Reach River Sta Profile Q Total Min Ch El W.S. EleY CrltW.S. E.G. Elev E.G. Slope Vel Chnl FlowArea Top Width Froude#Chl (cfs) (ft) (ft) (ft) (ft) (Mt) (ft/$) (sq ft) (ft) Primary P2 1 25YR 413.00 272.30 278.42 277.80 278.96 0.007002 6.16 84.53 53.12 0.61 Primary P2 1 100YR 620.00 272.30 279.10 278.59 279.74 0.007002 6.99 127.84 79.09 0.63 Primary P2 2 25YR 413.00 273.90 278.68 279.31 0.008447 6.39 68.73 37.49 0.68 Primary P2 2 100YR 620.00 273.90 279.28 280.14 0.009566 7.61 95.98 56.06 0.74 Secondary 51 5 25YR 70.00 274.20 279.28 276.63 279.31 0.000531 1.46 47.86 18.83 0.27 Secondary S1 5 100YR 108.00 274.20 280.10 277.10 280.14 0.000482 1.58 88.75 116.52 0.30 Secondary 51 5.5 Culvert Secondary 51 6 25YR 70.00 279.55 283.38 281.66 283.71 0.002624 4.57 15.33 4.00 0.41 Secondary fS1 6 100YR 108.00 279.55 284.70 282.37 285.13 0.003060 5.24 20.60 4.00 0.41 Secondary S1 6.5 Culvert Secondary s~ 7 25YR 70.00 279.60 284.41 280.75 284.42 0.000092 0.72 96.77 31.28 0.07 Secondary 51 ,, 7 100YR .. 108.00 279.60 285.59 281.07 285.60 0.000065 0.73 220.88 197.03 0.06 HEC-RAS Plan: PROP1 R.iver Reach River Sta " Profile E.G.US. w.s.us. E.G.IC E.G.OC Min El Ww Flow CulvQ QWtltr OeltaWS C\llvVel US CulVVelDS (ft) {ft) (ft) (ft} (ft) (cfs) (cfs) (11) {ft/5) (Ills) Secondlry S1 5.5 Culllert #1 25VR 283.71 283.38 283.43 283.71 285.11 70.00 4.11 8.36 5.57 Secondary S1 5.5 Culllertt1 100YR 285.13 284.70 285.13 285.11 285.11 107.98 0.02 4.60 10.19 8.59 Secondary S1 6.5 Cutvartl1 25YR 284.42 284.41 283.44 284.42 285.11 70.00 1.03 5.57 5.69 Seoondwy S1 6.5 Culvert#1 100YR 285.60 285.59 285.14 285.60 285.11 62.55 45.45 0.89 4.98 4.98