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FOR OFFICJ;_ }J~E ON L 'f P&Z CASE NO.: ()lD ·IL. I CrTY OF C OLLEGE STATION Planning & Development Services SITE PLAN APPLICATION DATE SUBMITTED:~·'\ .a:p '.l.03 ~ MINIMUM SUBMITTAL REQUIREMENTS .../ Site plan application completed in full. _.::!__ $200.00 Application Fee . .../ $200.00 Development Permit Application Fee. _.::!__ $600.00 Public Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public waterline, sewerline, sidewalk, street or drainage facilities is involved.) _.::!__ Twelve (12) folded copies of site plan N/A One (1) folded copy of the landscape plan. NIA One (1) copy of building elevation for all buildings. N/A A list of building materials for all facades and screening for non-residential buildings. NIA Color samples for all non-residential buildings. NIA Traffic Impact Analysis (if applicable for non-residential buildings). _.::!__ A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they are not checked off. N/A Parkland Dedication requirement approved by the Parks & Recreation Board, please provide proof of approval (if applicable). Date of Preapplication Conference: __ J"'"""a_n_u'--a'"'"ry......_2_0'--0"--6'------------------ NAME OF PROJECT Crescent Pointe Common Areas "G" & "I" -Drainage Improvements ADDRESS Approximately 700' sw of the Copperfield Pkwy I SH 30 Intersection fronting on SH 30 LEGAL DESCRIPTION Crescent Pointe Common Area "G" & Common Area "I" -per Final Plat & Replat Phase 2 APPLICANT/PROJECT MANAGER'S INFORMATION (Primary Contact for the Project): Name Crescent Pointe Holdings, Inc. -Emanuel Glockzin -President Street Address 4500 Carter Creek Pky, Suite 101 City Bryan State Texas Zip Code _77~8~0=2~---- Phone Number (979) 846-8878 E-Mail Address-------------- Fax Number (979) 846-0783 PROPERTY OWNER'S INFORMATION: Name Same as Applicant Street Address--------------------City ___________ _ State _____ Zip Code ______ _ Phone Number ____________ _ ARCHITECT OR ENGINEER'S INFORMATION: Name Kling Engineering & Surveying Street Address 41 01 Texas Ave State Texas Zip Code ~77~8~0=2~---- Phone Number (979) 846-6212 6/13/03 E-Mail Address _____________ _ Fax Number ______________ _ City Bryan E-Mail Address Fred@klingeng I Stewart@klingeng Fax Number (979) 846-8252 l of6 DEVELOPMENT PERMIT PERMIT NO. 06-47 CITY OF COLLEGE STATION Plannint cf Dtwlopmmt &rvius FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: Crescent Pointe Common Areas G & I DATE OF ISSUE: November 8, 2006 OWNER: Crescent Pointe Holdings, Inc. 4500 Carter Creek Pkwy, Suite 101 Bryan, Texas 77802 SITE ADDRESS: 700-ft SW of SH 30/Copperfield Intersection DRAINAGE BASIN: Carter's Creek VALID FOR 12 MONTHS CONTRACTOR: TYPE OF DEVELOPMENT: Full Development Permit SPECIAL CONDITIONS: All construction must be in compliance with the approved construction plans All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section 7.5.E., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance, prior to any operations of this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and required to remain is strictly prohibited. The disposal of any waste material such as, but not limited to, paint, oil, solvents, asphalt, concrete, mortar, or other harmful liquids or materials within the drip line of any tree requ ired to remain is also prohibited. Full Development Permit 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 cond ition, 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. 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 sed imentation 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. Date 1 l-9-0Lp Date 11/07/2006 22:03 2 3 3 290 4 5 6 8 0.5 9798468252 Clearing and Grubbing, ;ind dispOSal of cleared matenals for Oollars and Cents per acnt. LF Furnish and Install 18" HOPE, poblic storm sewer, complete and in place for Ool"'rs and Cent$ J>l'r linear fool LF Furnish and Install 30• HOPE, public storm sewer, oomplete and in place for Dollars and Cents per linear foot. EA Fumish and Install Reinforoed Concrete 4:1 Sloped End Treatment for 30" HOPE, with trash rack per detail, complete and in place for Dollars and Cent:i each. (U m and Downstream Ends EA Furnish and Install 4'x4' Reinforced CorterVl\I Junction Box. -6' depth, complete and in place for Dollars and Cents each. EA Furnish and Install 4'x5' Reinforced Concrete Junction Box, -{;' depth, complete and in place for Dollars and Cents each. SUBTOTAL. 1: (ITEMS 1~) LS Furnish, Install, and maintain all necessary Erosion and Sediment Control Measures (to Include coJlStruction exit. sit! fencing, haybales. brush piles, and oth<:ir ~lln'e$ called out on SWP3) complete and in plaoe for Dollars and Cents per lump sum. AC Furnish and Install Hydromulch In Accon:tance with Sheet C2.1 . complete and in place for Dollars and Cents per aae. SUBTOTAL2: (ITEMS 7-9) ESTIMATE SUMMARY SUBTOTAL1: SUBTOTAL2: TOTAL CONSTRUCTION COSTS: 10%Contin TOTAL ESTIMATED COSTS: PAGE 02/02 $30.00 $90.00 $60.00 $17.400.00 $2,000.00 $2,000.00 $3,000.00 $3,000.00 $3,200;00 $3,200.00 $26,190.00 $2,000.00 $2,000.00 $4,200.00 $2,100.00 $4,100.00 $26,190.00 $4,100.00 $30,290.00 $3029.00 $33 319.00 DRAINAGE REPORT FOR Lots 1-4 Block 2 Crescent Pointe Phase One, Vol. 6880, Pg. 188 & An Additional 10.87 Acres of Block 2 of Crescent Pointe J. W. Scott Survey, A-49 College Station, Brazos County, Texas August 11, 2006 Revised: September 7, 2006 DEVELOPED BY: Crescent Pointe Holdings, Inc. Emanuel Glockzin, Jr., President 4500 Carter Creek Parkway, Suite 101 Bryan, Texas 77802 PREPARED BY: Kling Engineering & Surveying 4101 S. Texas Avenue, Suite A Bryan, TX 77802 (979) 846-6212 Drainage Report for Lots 1-4 Block 2 Crescent Pointe -Drainage Report -Page 1 Crescent Pointe Phase One, Vol. 6880, Pg. 188 & An Additional 10.87 Acres of Block 2 of Crescent Pointe J. W. Scott Survey, A-49 College Station, Brazos County, Texas August 11, 2006 Revised: September 7, 2006 GENERAL LOCATION & DESCRIPTION: For purposes of this drainage design and report, the "Project Area" shall be defined as follows: • Lots l-4,Block2(4.20acres)ofPhase l (Vol.6880,Pg.188) • A remaining 10.87 acres of Block 2 • Total Project Area acreage: 15.08 acres The Project Area is located at the west comer of the Copperfield Parkway/State Highway 30 intersection. The Project Area is bounded on the northeast by Copperfield Parkway, on the southeast by State Highway 30 (SH No. 30), and on the northwest by Crescent Pointe Parkway. The southwest boundary of the Project Area is the western lotline of Lot 5R, Block 2 then extending from the lot's southwest comer, perpendicular to the SH No. 30 Right-of-Way (refer to Appendix 1: "Vicinity Map"). Pre-development or existing conditions of the Project Area consist of vacant land covered with a mixture of short grass pasture, scattered brush/wooded areas and natural and man made drainage ditches. The average sub basin slope is 2.1 % as measured along the Project Area's hydraulic length. Based on the current USDA National Resources Conservation Service Soil Survey for Brazos County, Texas, the native soils are in hydrologic soil group D (refer to Appendix 5a -"Hydrologic Calculations -Pre Development Conditions"). Currently, office/commercial development is planned for the Project Area. PURPOSE: The purpose of this report is to document the storm water management for the full development of the Project Area. Proposed development for the areas included in this drainage report consist of office and commercial uses. This planned development is expected to occur in phases, therefore this report will document the design parameters for planned development of the entire Project Area. Detention will be provided within a privately maintained, project specific drainage facility. Future development must be hydraulically compatible with this design. Future development within the Project Area will only need to document that runoff coefficients do not exceed those assumed in this report and demonstrate conveyance of site stormwater runoff to the drainage facility. Crescent Pointe -Drainage Report -Page 2 DRAINAGE BASIN: The site is located in the Carters Creek drainage basin, which is the primary drainage system. The Project Area is in the secondary system and drains directly into an unnamed tributary of Carters Creek (see Appendix 2: "General Location Map"). No portion of the site is within the 100 year flood hazard area according to the Flood Insurance Rate Map for Brazos County, Texas and Incorporated Areas number 48041C0161 C, Effective date: July 2, 1992, (see Appendix 3: "Flood Insurance Rate Map"). The major sub-basin for the Project Area is approximately 22.23 acres (refer to Appendix 4 "Drainage Area Maps). The sub-basin outfall structure is a TXDOT culvert consisting of a 36" RCP. The culvert crosses State Highway No.30 approximately 650 feet southwest of the Copperfield Parkway/SH No.30 intersection. The sub-basin area is generally divided as follows: 4.56 acres: Northwest of Crescent Pointe Pkwy. (Including a portion of Crescent Pointe Pkwy and Copperfield Pkwy Ri ghts-of-Way) 15 .08 acres: Southeast of Crescent Pointe Pkwy. and southwest of Copperfield Pkwy. 2.59 acres: TXDOT SH No. 30 Right-of-Way (Including a portion of Copperfield Pkwy. Right-of- Way) DRAINAGE DESIGN CRITERIA: Due to the expected increase in storm water runoff for post development conditions, a drainage facility will be designed to attenuate the 2 year through 100 year storm events. Stormwater from the entire Project Area is to be conveyed to the drainage facility via overland flow and future public and private storm sewer systems (private storm sewer not designed with this report). It is imperative that during individual site development, the site grading & drainage plans accommodate conveyance of storm water runoff to the drainage facility. This is a requirement for all site areas as depicted on the post developed drainage area map (refer to Appendix 4). An additional design constraint is the existing Project Area outfall structure (TXDOT 36" RCP at SH No. 30). The TXDOT culvert is a channel restriction and causes undesigned detention to occur on-site in an existing area of ponding. This has a limiting effect on total site runoff. Allowable discharge from the developed site will be less than or equal to the pre-developed runoff rate for the various storm events. The Uplands Method was used to calculate travel times along sub-basin hydraulic lengths and time of concentration. The Rational Method was used to calculate peak runoff rates for both pre and post developed conditions. A triangular hydrograph approximation with the following parameters was used to develop runoff hydrographs: Time to Peak (Tp) = Time of Concentration (Tc) Tp = 1/3 Hydrograph Base Time (Rising Limb of Hydrograph) 3Tp = Hydrograph Base Time Crescent Pointe -Drainage Report -Page 3 Level Pool Routing was used in the pre-developed conditions analysis to route hydrographs through the existing ponding area with the appropriate hydraulic equations used to model the TXDOT structure. The drainage facility design proposes approximately 300 LF of public storm sewer and a single, privately maintained detention pond. Conditions at the site exist such that, for post development conditions, the water surface upstream of the project outfall may effect the performance of the design pond. An "interconnected" pond routing procedure was used for post development conditions (to be discussed in the "Drainage Facilities Design -Post Development Conditions -Detention Facilities Design" section). DRAINAGE FACILITIES DESIGN: Pre Development Conditions: Project Drainage Areas: The project sub-basin is divided into two drainage areas. Drainage area "DA-lA-PRE" is on the northwest side of Crescent Pointe Pkwy and encompasses approximately 3.06 acres ofland uses consisting currently vacant property and 1.50 acres of Crescent Pointe Parkway and Copperfield Parkway Rights-of-Way. The area was delineated based on City of College Station 2' topographic maps, Crescent Pointe Pkwy construction plans, as well as field surveyed topographic information. Drainage area "DA-lB-PRE" is located on the southeast of Crescent Pointe Pkwy northwest of the Copperfield Parkway/SH No. 30 intersection and encompasses approximately 17.67 acres of vacant property, existing channel, and SH No. 30 Right-of-Way . Delineation for this area was based on City of College Station 2' topographic maps, field surveyed topographic information, and field inspection of existing public storm sewer in Copperfield Pkwy (see Appendix 4: "Drainage Area Maps"). The following table summarizes pre developed drainage areas and associated land cover. DRAINAGE GRASS/ RIGHT OF WAY/ CHANNEL TOTAL AREA PASTURE IMPERVIOUS /POND AREA (acres) (C=0.42) (C=0.90) (C=0.90) (acres) DA-1A-PRE I 3.06 I 1.50 I -I 4.56 DA-18-PRE 13.84 1.79 2.04 17.67 TOTAL ACRES: 16.90 3.29 2.04 22.23 Table 1 Hydrologic & Hydraulic Analysis: Times of concentration for the various drainage areas were computed using the Uplands Method. Intensities for the various storm events were computed based on the Brazos County Intensity Duration Frequency curves for the corresponding times of concentration. Peak flow rates for each drainage area were calculated using the Rational Method (refer to Appendix 5 "Hydrologic Calculations -Pre Development Conditions" for computations). Crescent Pointe -Drainage Report -Page 4 The following table summarizes the peak runoff rates for the various storm events. Q (cfs) DRAINAGE Tc C-Value Area 2 yr 5 yr 10 yr 25 yr 50 yr 100 yr AREA (mini (a cl DA-1A-PRE 10.00 0.58 4.56 16.66 20.25 22.73 25.96 29.35 30.64 DA-18-PRE 18.82 0.52 17.67 42.45 52.42 59.34 68.01 77.15 80.50 Table 2 The above peak flow rates were used in the existing conditions hydrograph generation. After summation of the sub-area hydrographs, the resultant hydro graph was routed through the TXDOT structure utilizing existing upstream channel area for storage volume. The final peak flow rate through the TXDOT structure was used to set the maximum allowable discharge from the Project Area. Detention Routing: Upstream of the Project Area outfall, there exists a depressed drainage way/channel. The channel extends northwest through the Project Area (refer to Appendix 4 "Drainage Area Maps"). The combination of the TXDOT structure and the drainage way effect undesigned detention. To determine pre developed discharge rates from the project outfall, the existing system was modeled as a detention pond with the TXDOT structure as it's outlet. Kling Engineering & Surveying conducted a topographic survey of the Project Area and from that information, the available volume for storage was computed. The following information documents existing conditions parameters used in the model. Drainage Way/Channel Volume: 2B-PRE Upstream of SH No. 30 Elevation Area Volume (ft) (sq.ft) (ac-ft) 263 3 0.000 264 32 0.000 265 91 0.001 266 188 0.003 267 346 0.006 268 571 0.010 269 886 0.017 270 1587 0.028 271 2890 0.051 272 4327 0.082 273 6834 0.127 274 11779 0.211 Volume Sum (ac-ft) 0.000 0.000 0.002 0.005 0.011 0.021 0.038 0.066 0.117 0.199 0.326 0.537 Table 3 TXDOT Structure: 2B Size/Type: 36" RCP Manning's n: 0.013 Upstream FL: 262.57 Downstream FL: 258.00 Horiz. Length: 11 7.00 ft Slope: 3.91 % Crescent Pointe -Drainage Report -Page 5 The following table summarizes total discharges from the existing Project Area under pre developed conditions (refer to Appendix 6a "Detention Routing Calculations -Pre Development Conditions"). PEAK DISCHARGE STORM EVENT RATE (CFS) 2YR SYR 10YR 25YR SOYR 100 YR DA-1A-PRE 17 20 23 26 29 31 DA-18-PRE 42 52 59 68 77 80 DA-1 B-PRE Inflow 51 62 70 81 91 95 Project Outfall / 481266.7 58 / 267.5 66 / 268.2 74/269.1 831270.0 851270.3 WSEL Project Outfall 6.79 8.20 9.34 10.47 11 .74 12.02 Velocity (fps) *reported values vary slightly from calculated values due to differences in the runoffhydrograph and routing procedure calculation time steps Table 4 Post Development Conditions: Project Drainage Areas: Under post developed conditions, the TXDOT structure will continue to serve as the Project Area outfall. The project's detention pond will discharge into the SH No. 30 right of way and be routed through this culvert. The storage volume within the right of way will be treated as an interconnected pond. This volume will be modeled as a detention area with the TXDOT structure used as the outlet works. Peak discharge rates through the culvert will be limited to pre development discharge rates. The post developed drainage area and sub areas remain relatively unchanged from the pre developed areas. The drainage area upstream of Crescent Pointe Pkwy was reduced to an equivalent post developed area generating the same peak runoff rate as the pre developed area (from 22.23 ac. to 20.77 ac.). Based on City of College Station 2' digital topography maps, it is possible to storm sewer the entire Project Area into the proposed drainage facilities. This requires storm sewer is to be designed & constructed during the site development phase of the associated lots (see Appendix 4: "Drainage Area Maps"). A 300 LF portion of public storm sewer design will be documented in this project. Due to the lack of final site plans for the Project Area, the assumption that maximum impervious lot coverage could not exceed 80% was made. The remaining 20% of the lot area is assumed to be landscaped or grassed. Crescent Pointe -Drainage Report -Page 6 The following table summarizes post developed drainage areas, associated land cover and the respective Rational runoff coefficient "C". DRAINAGE AREA DEV. LOT 1, IMPERVIOUS CHANNEL/ UNDEVELOPED TOTAL (acres) AREA BLOCK2 AREAS POND AREAS AREA IC=0.77) IC=0.59) <C=0.90\ <C=0.90\ IC=0.42\ tacresl DA-1A-POST 0.83 -1.50 -0.30 2.63 DA-18-POST 12.50 1.11 -1.46 -15.07 nt.-1C-POST --1 7q -1 ?R ".\ 07 TOTAL ACRES: 13.33 1.11 3.29 1.46 1.58 20.77 Table 5 It should be noted that drainage area DA-lC-POST is the only drainage area that does not flow into the detention facilities or improved channel but directly into the right of way areas. Proposed Drainage Improvements: Project Area drainage improvements will consist of approximately 300 LF of 30" HDPE storm sewer and a single, privately maintained detention pond. The proposed detention pond will be constructed in such a way as to limit impacts to Jurisdictional Waters of the U.S. Wherever possible, the flow line of the pond will be lower than the existing channel flow line. Hydrologic & Hydraulic Analysis: Times of concentration for the various drainage areas and sub-areas were computed using the Uplands Method. For instances when the computed time was less than 10 minutes, a minimum of 10 minutes was used. Intensities for the various storm events were computed based on the Brazos County Intensity Duration Frequency curve for the corresponding times of concentration. Peak flow rates for each drainage area were calculated using the Rational Method (refer to Appendix Sb "Hydrologic Calculations -Post Development Conditions" for computations). The following table summarizes the peak runoff rates for the various storm events. a (cfs) DRAINAGE Tc C-Value Area 2 yr I 5 yr 10 yr 25 yr 50 yr 100 yr AREA (minl (a cl DA-1A-POST 10.00 0.80 2.63 13.37 16.26 18.25 20.85 23.57 24.61 DA-18-POST 10.00 0.77 15.08 73.38 89.22 100.15 114.38 129.30 135.00 DA-1C-POST 10.00 0.70 3.07 13.59 16.52 18.55 21.18 23.95 25.00 Table 6 Crescent Pointe -Drainage Report -Page 7 Storm Sewer Facilities Design: Public storm sewer facilities were designed to provide drainage from Lots 1-4, Block 2 of Crescent Pointe Phase 1 to the detention pond at Common Area "I". The public storm sewer will connect to a public 18" HDPE storm sewer line at the southeast property line of Lot 2, Block 2 with a reinforced concrete junction box. Approximately 300 LF of public storm sewer will be installed with an additional junction to change the angle in which the line enters the pond. The public storm sewer was designed to handle the ultimate development, 100 yr. runoff from the four contributing lots. It was determined that a 30" HDPE pipe would accomodate the 100 yr. flowrates. The following table shows calculated values in the 30" public storm sewer (refer to Appendix 6 "Hydraulic Calculations -Storm Sewer" for computations). INLET I GROUND Q100 PIPE SIZE PIPE SIZE FLIN FLOUT HGL VELOCITY JUNCTION ELEV. (FT) (CFS) IN(IN.) OUT(IN.) (FT) (FT) (FT.) (FPS) 1-1 290.00 19.26 18-HDPE 30-HOPE N/A 286.00 287.72 10.90 1-2 289.65 35.48 30-HDPE 30-HOPE 285.93 283.16 285.18 7.23 J-2 285.00 35.48 30-HDPE 30-HOPE 280.67 278.25 280.48 7.23 OUTFALL 284.00 35.48 30-HDPE N/A 278.05 N/A 278.01 N/A Detention Facilities Design: In order to compute the ultimate, post development discharge rates for the Project Area outfall structure, it was necessary to create a model that analyzed two separate pond/storage areas. These areas are defined as follows: Pond lB Pond IC Detention pond created immediately south of Crescent Pointe Parkway Right of Way storage area immediately north of SH No. 30 These areas are "interconnected". Interconnected pond modeling is used when the water surface elevation downstream of an outlet structure varies with time. Since tailwater elevations affect discharge rates from upstream structures, the design pond area was considered as interconnected. To accomplish interconnected pond routing, calculation of multiple rating tables for a given outlet device under varying tail water conditions is performed. Graphs of these rating tables for the detention pond outlets are located in Appendix 6b, "Detention Routing Calculations -Post Development Conditions" for reference. Crescent Pointe -Drainage Report -Page 8 The drainage system was designed so that the peak, post developed flow rates discharged through the TXDOT structure did not exceed pre-developed flow rates. The following information documents design parameters used in the model. Detention Pond Characteristics: Pond lB Pond lC -Right of Way Storage Elev Area Volume Volume Elev Area Volume Volume Sum Sum (ft) (sq.ft) (ac-ft) (ac-ft) (ft) (sq.ft) (ac-ft) (ac-ft) 272 2235 0.01 7 0.017 263 3 0.000 0.000 273 5010 0.081 0.098 264 32 0.000 0.000 274 8129 0.149 0.248 265 91 0.001 0.002 275 11325 0.222 0.470 266 188 0.003 0.005 276 13685 0.287 0.756 267 346 0.006 0.01 1 277 16459 0.346 1.102 268 571 0.010 0.021 278 19727 0.415 1.517 269 886 0.017 0.038 279 23743 0.498 2.015 270 1348 0.025 0.063 271 1952 0.038 0.101 272 2665 0.053 0.154 273 4487 0.081 0.235 Table 7 Table 8 The limits of Pond lB are calculated to elevation 279. The right of way storage volume is calculated to elevation 273 . Low flow flumes are not proposed in an effort to avoid impacts to the Jurisdictional Waters of the U.S. Outlet Works: The Pond lB outlet is a 30" RCP and 45' long, 8' wide broad crested earthen weir. As in the existing conditions model, the TXDOT 36" RCP culvert is the outlet for the SH No. 30 right of way ponding area (Pond lC). The following is a summary of the outlet structures for each of the pond areas. Pond lB: TXDOT Structure: Pond IC Sizeffype: 30" RCP Size/Type: 36" RCP Manning's n: 0.013 Manning's n: 0.013 Upstream FL: 271.00 Upstream FL: 262.57 Downstream FL: 269.00 Downstream FL: 258.00 Horiz. Length: 83.0' Horiz. Length: 117.0' Slope: 2.41 % Slope: 3.91 % Overflow Spillway: Emrgncy Spillway: SH No.30 @ elev. 278.00 @ elev. 276.00 Crescent Pointe -Drainage Report -Page 9 The following schematic diagram depicts the calculation sequence for the post developed conditions hydrologic and routing model. DAlA-PST-10 ./J"IJ, "'',O ;rl',, .coo DAlB-PDST DAlB-PST-100- DAlC-PDST DAlC-PST-100- DAlB-EX 0 Junction 0 HYG c:fotQ 0 Pond Add HYG Outlet Figure 1 Crescent Pointe -Drainage Report -Page 10 The following table summarizes results of ultimate development. storm water routing. Refer to Appendix 6b "Detention Routing Calculations -Post Development Conditions" for computation summary and graphical representation of hydro graphs and pond water surface elevations. PEAK DISCHARGE RA TE STORM EVENT (CFS) 2YR 5YR 10YR 25YR 50YR 100YR DA-1A-POST 13 16 18 21 24 25 DA-18-POST 73 89 100 114 129 135 DA-1 B-POST Inflow 78 95 107 122 138 144 DA-1 B-POST Outfall I WSEL 41 / 275.5 46 / 276.2 49 / 276.7 53 / 277.2 561277.8 59 / 278.0 DA-1 B-POST Discharge 8.35 9.37 9.98 10.79 11.41 12.02 Velocity DA-1C-POST 14 17 19 21 24 25 DA-1 C-POST Inflow 49 56 60 65 70 72 Project Outfall I WSEL 48 / 266.7 54 / 267.2 58 / 267.5 63 / 267.8 67 / 268.3 69 / 268.5 Project Outfall Velocity 6.79 7.64 8.20 8.91 9.48 9.76 *reported values vary slightly from calculated values due to differences in the runoffhydrograph and routing procedure calculation time steps Table 9 The overflow weir for Pond lB is utilized during the 100 year event. Additionally, at the 100 year event, freeboard of 1.0' is maintained for Pond lB. Based on field topographic survey information, the top of pavement forSH No. 30 is approximately 276. As shown in the above post development routing summary, the roadway is not overtopped at the 100 year event. The outfall for Pond lB is upstream of SH No. 30 Right-of-Way. Peak discharge rates to the SH. No. 30 R.O.W. are less than existing conditions. Peak discharge through the 36" RCP Project Outfall are less than or equal to existing conditions. At the upstream end of the project outfall, the pre- developed peak water surface elevation is 270.3' and the post-developed peak water surface elevation is 268.5' for the 100 yr. storm event. Energy dissipaters are provided at the downstream end of the pond outlet to limit the effects of outlet velocities. No change in flow conditions entering the R.O.W. is expected. Henton-Lincoln Subdivision -Drainage Report -Page 11 The following table compares pre and post development peak discharge rates from the Project Area Outfall. PEAK DISCHARGE RATE (CFS) STORM EVENT TO SH NO. 30 R.O.W. 2YR SYR 10YR 25YR SOYR 100YR Pre Developed 51 62 70 81 91 95 Post Developed 49 56 60 65 70 72 % Attenuation II 105 111 117 125 130 132 PEAK DISCHARGE RATE (CFS) STORM EVENT THROUGH PROJECT OUTFALL 2YR SYR 10YR 25YR SOYR 100YR Pre Developed 48 58 66 74 83 85 Post Developed 48 54 58 63 67 69 Table 10 CONCLUSIONS: The storm sewer and detention facility design complies with the City of College Station requirements. The detention pond attenuates excess runoff through the 100 year storm event. No adverse impacts to upstream or downstream lands or structures are expected. "I hereby certify that this report for the drainage & detention design of: Lots 1-4 Block 2 Crescent Pointe Phase One & An Additional 10.87 Acres of Block 2 of Crescent Pointe was Licensed Professional Engineer State of Texas No. 97221 APPENDICES 1) Vicinity Map 2) General Location Map 3) Flood Insurance Rate Map 4) Drainage Area Maps 5) Hydrologic Calculations -Pre & Post Development Conditions 6) Hydraulic Calculations -Storm Sewer 7a) Detention Routing Calculations -Pre Development Conditions 7b) Detention Routing Calculations -Post Development Conditions APPENDIX 1 Vicinity Map FM 60 LINDA APPENDIX 2 General Location Map APPENDIX4 Drainage Area Maps APPENDIX 3 Flood Insurance Rate Map APPENDIX 5 Combined Hydrologic Calculations Pre Development Conditions & Post Development Conditions 0 i USDA NtllUral Resourcet ~ Consenllllon Servlct HYDROLOGIC GROUP RATING FOR BRAZOS COUNTY, TEXAS 760800 761000 ••c::=•••-Meters .. c::::::::111m:::::. ........ c:::=======-...... _.Feet 0 100 200 400 Web Soil Survey 1.1 National Cooperative Soil Survey 0 400 800 1,600 2,400 3,200 8/8/2006 Page I of4 USDA No1ura1 Reooartft -Coosenatlon SerYltt HYDROLOGIC GROUP RATING FOR BRAZOS COUNTY, TEXAS MAP LEGEND Hydrologic Group {Dominant Condition, &It;} A [==:J AID -B C::=J BID [=:::J c -CID C:=J D [==:J Not rated or not available Soil Map Units o Cities c::J Detailed Counties c::::::J Detailed States -Interstate Highways --Roads -+--+-Rais -Water --Hydrography -Oceans MAP INFORMATION Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: UTM Zone 14 Soil Survey Area: Brazos County, Texas Spatial Version of Data: 1 Soil Map Compilation Scale: 1 :20000 Map comprised of aerial images photographed on these dates: 215/1995; 2/6/1995 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Web Soil Survey 1.1 National Cooperative Soil Survey 8/8/2006 Page 2 of 4 Hydrologic Group Rating Tables -Hydrologic Group Summary by Map Unit -Brazos County, Texas Soil Survey Area Map Unit Name Rating Total Acres in Percent of AOI Map Unit AOI Symbol BoB Boonville fine sandy D 99.0 30.3 loam. l to 3 percent slopes BuA Burleson clay 0 to I D 2.3 0.7 percent slopes ChC Chazos loamy fine sand, l c 15.l 4.6 to 5 percent slopes GrC Gredge fine sandy loam, 1 D 4.7 1.4 to 5 percent slopes GrC2 Gredge fine sandy loam, 2 D 34.5 10.6 to 5 percent slopes, eroded RbA Rader-Tabor complex, l D 15.1 4.6 to 3 percent slopes TaA Tabor fine sandy loam, 0 D 15.0 4.6 to 2 percent slopes ZaB Zack fine sandy loam. l D 27.3 8.3 to 5 percent slopes ZaC2 Zack fine sandy loam. 2 D 34.3 10.5 to 5 percent slopes, eroded ZuB Zulch fine sandy loam, 1 D 79.7 24.4 to 3 percent slopes Description -Hydrologic Group Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are placed into four groups A, B, C, and D, and three dual classes, ND, BID, and CID. Definitions of the classes are as follows: The four hydrologic soil groups are: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water USDA Notunl ll.....,.... -Couen'llllon Senlct Web Soil Survey I.I National Cooperative Soil Survey 8/8/2006 Page 3 of4 ·, '· I Hydrologic Group Rating transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (AID, BID, or CID), the first letter is for drained areas and the second is for undrained areas. Only soils that are rated Din their natural condition are assigned to dual classes. Parameter Summary -Hydrologic Group Aggregation Method: Dominant Condition Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole. A map unit is typically composed of one or more "components". A component is either some type of soil or some nonsoil entity, e.g., rock outcrop. For the attribute being aggregated, the first step of the aggregation process is to derive one attribute value for each of a map unit's components. From this set of component attributes, the next step of the aggregation process derives a single value that represents the map unit as a whole. Once a single value for each map unit is derived, a thematic map for soil map units can be rendered. Aggregation must be done because, on any soil map, map units are delineated but components are not. For each of a map unit's components, a corresponding percent composition is recorded. A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit. Percent composition is a critical factor in some, but not all, aggregation methods. The aggregation method "Dominant Condition" first groups like attribute values for the components in a map unit. For each group, percent composition is set to the sum of the percent composition of all components participating in that group. These groups now represent "conditions" rather than components. The attribute value associated with the group with the highest cumulative percent composition is returned. If more than one group shares the highest cumulative percent composition, the corresponding "tie-break" rule determines which value should be returned. The "tie-break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie. The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred. Component Percent Cutoff: Components whose percent composition is below the cutoff value will not be considered. If no cutoff value is specified, all components in the database will be considered. The data for some contrasting soils of minor extent may not be in the database, and therefore are not considered. Tie-break Rule: Lower The tie-break rule indicates which value should be selected from a set of multiple candidate values, or which value should be selected in the event of a percent composition tie. USDA Nlllural R .... rces -eo-m.tlon Senlce Web Soil Survey l.l National Cooperative Soil Survey 8/8/2006 Page4of4 , I INTENSITY CALCULATIONS BRAZOS COUNTY CONSTANTS FOR IDF CURVES FREQ e b d 2 0.806 65 8.0 5 0.785 76 8.5 10 0.763 80 8.5 25 0.754 89 8.5 50 0.745 98 8.5 100 0.730 96 8.0 INTENSITY=b/(Tc+d)Ae FREQ Tc (min) 2 5 10 25 50 100 PRE DA-1A 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64 DA-18 18.82 4.59 5.66 6.41 7.35 8.34 8.70 POST DA-1A 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64 DA-18 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64 DA-1C 10.00 6.33 7.69 8.63 9.86 11 .15 11 .64 I I E I I [ [ r r - L RUN-OFF COEFFICIENT (C-VALUE) CALCULATIONS C-VALUES PRE DA-1A DA-18 TOTAL: POST DA-1A DA-18 DA-1C TOTAL: GRASS/WOODED 0.42 CHANNEL 0.90 IMPERV 0.90 DEV 0.77 AREA in Acres GRASS/WOODED IMP ERV CHANNEL TOTAL 3.0588 1.4977 0.0000 4.557 13.8387 1.7878 2.0357 17.662 16.8975 3.2855 2.0357 22.2187 DEV IMP ERV UN DEV LOT 1 0.8290 1.4977 0.3042 0.0000 12.5012 0.0000 0.0000 1.1100 0.0000 1.7878 1.2834 0.0000 13.3302 3.2855 1.5876 1.11 UN DEV LOT 1 POND 0.0000 1.4640 0.0000 1.464 PEAK FLOW CALCULATIONS TC C-VALUE AREA Q2 Q5 PRE (minutes) (ac) (cfs) (cfs) DA-1A 10.00 0.58 4.5565 16.66 20.25 DA-18 18.82 0.52 17.6622 42.45 52.42 POST DA-1A 10.00 0.80 2.6309 13.37 16.26 DA-18 10.00 0.77 15.0752 73.38 89.22 DA-1C 10.00 0.70 3.0712 13.59 16.52 where: Q = C-Value *Area * I I -is found in "Intensity Calculations" and corresponds to the appropriate Tc and frequency. 0.42 0.59 TOTAL 2.6309 15.0752 3.0712 20.7773 Q10 (cfs) 22.73 59.34 18.25 100.15 18.55 POND C-AVE 0.58 0.52 0.80 0.77 0.70 Q25 (cfs) 25.96 68.01 20.85 114.38 21 .18 0.9 Q50 Q100 (cfs) (cfs) 29.35 30.64 77.15 80.50 23.57 24.61 129.30 135.00 23.95 25.00 APPENDIX 6 Hydraulic Calculations -Storm Sewer J-2 P-4 Outlet Project Title: DA-1 STORM SEWER h:\ ... \drainage\detention area 1 \da-1 st .stm 08/11/06 02:54:26 PM P-2 KLING ENGINEERING CC> Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 1-1 I . I I . t 1 P'-1 Project Engineer: KLING ENGINEERING StormCAD v1 .0 Page 1 of 1 Ju 1ction: J-2 et: Outlet Outl Rim Sum Ri1 n:_~8 .... 5~QO .... ~ = s_ ~ : ~84 .00 ft 11~:~ - ~ ~ ---- + + 0 00 0 50 Pipe: P-4 Up Invert: 278.25 ft On Invert: 278.05 ft Length: 40.69 ft Size: 30 inch Project Title: DA-1 STORM SEWER -------- -- + 1 00 Inlet: 1-2 Rim: 289.65 ft Sump: 283.16 ft ------------------------ \ Pipe: P 2 up inve On lnve Length: Size: 3C + 1 50 Station ft c ..::o~. 10 n 1: 280.67 ft 252.24 ft inch 2 00 + KLING ENGINEERING --- 2 50 + h:\ ... \drainage\detention area 1\da-1 st .stm 08/11/06 02:56:07 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 - [\ Inlet: 1-1 Rim: 290.00 ft Sump: 286.00 ft 290.00 28 8.00 2 86.00 } 8\ Elevation ft 2 82.00\ I 2 80.00 Pipe: P-1 i Up Invert: 286.00 ft On Invert: 285.93 ft Length: 3.00 ft Size: 18 inch ' 2 + 78.00 3 00 I I ' l Project Engineer: KLING ENGINEERING StormCAD v1 .0 Page 1 of 1 Node Inlet Weighted Inlet Externa Total Area ~oughnes CA CA CA (acres) Coefficien (acres) (acres) (acres) 1-1 2.28 0.72 1.64 0.00 1.64 1-2 1.92 0.72 1.38 0.00 3.02 J-2 N/A N/A NIA NIA 3.02 Outle N/A NIA NIA NIA 3.02 Project Title: DA-1 STORM SEWER h:\ ... \drainage\detention area 1\da-1 st .stm 08/11/06 02:54:33 PM Inlet TC (min) 10.00 10.00 NIA N/A od epo Extern a Jpstrean '5ysterr System Total l'.\dditiona Carryove Known Total Dischargt Ground TC Flow Flow lntensit} Nate rs he< Flow (cfs) Flow Upstrean (cfs) Elevatior (min) Time Time (in/hr) (CIA) (cfs) (cfs) Added (ft) (min) (min) (cfs) (cfs) 0.00 0.00 10.00 11 .64 19.26 0.00 0.00 0.00 0.00 19.26 290.00 0.00 10.00 10.00 11.64 35.48 0.00 0.00 0.00 0.00 35.48 289.65 0.00 10.46 10.46 11 .64 35.48 NIA NIA NIA 0.00 35.48 285.00 0.00 10.55 10.55 11 .64 35.48 N/A N/A N/A 0.00 NIA 284.00 KLING ENGINEERING © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Rim HGL In HGLOu Inlet Inlet Elevatior (ft) (ft) lntensil\ Discharge (ft) (in/hr) (cfs) 290.00 287.50 287.50 11 .64 19.26 289.65 285.18 285.18 11 .64 16.22 285.00 280.48 280.48 NIA N/A 284.00 278.01 278.01 NIA N/A Project Engineer: KLING ENGINEERING StormCAD v1 .o Page 1 of 1 Pipe Upstrean lownstrean ~ Inlet Weighted Node Nod~ Area Roughnes (acres) Coefficien P-1 1-1 1-2 2.28 0.72 P-2 1-2 J-2 1.92 0.72 P-4 J-2 Outlet NIA NIA Project Title: DA-1 STORM SEWER h:\ ... \drainage\detention area 1\da-1 st .stm 08/11/06 02:54:40 PM Inlet CA (acres) 1.64 1.38 NIA Pipe Report Total System PischargE Length i::onstructe1 Section ~oughnes (:apacit) Jpstrean ~ownstrean li.Jpstrean CA lntensit~ (cfs) (ft) Slope Size (cfs) Invert Invert Ground (acres) (in/hr) (ft/ft) Elevatior Elevation Elevatior (ft) (ft) (ft) 1.64 11 .64 19.26 3.00 0.023333 18 inct 0.012 17.38 286.00 285.93 290.00 3.02 11 .64 35.48 ~52 .24 0.009872 30 inct 0.012 44.15 283.16 280.67 289.65 3.02 11 .64 35.48 40.69 0.004915 30 inct 0.012 31 .15 278.25 278.05 285.00 KLING ENGINEERING © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 ~ownstrean li.Jpstrean ~ownstrean li.Jpstreanr Ground Cover Cover HGL Elevation (ft) (ft) (ft) (ft) 289.65 2.50 2.22 287.50 285.00 3.99 1.83 285.18 284.00 4.25 3.45 280.48 Project Engineer: KLING ENGINEERING StormCAD v1 .0 Page 1 of 1 APPENDIX 7a Detention Routing Calculations Pre Development Conditions yyyTable of Contentsy i Table of Contents ******************** NETWORK SUMMARIES ********************* DAl-PRE-25 ...... 25 YR Executive Summary (Nodes) 1 .01 *********************** POND VOLUMES *********************** DAlB-PRE ........ Vol : Elev-Area .................... . 2.01 ******************** OUTLET STRUCTURES ********************* EX -DA1B-SH30 .... Outletyinput Data ................. . Individual Outlet Curves .......... . Composite Rating Curve ............ . 3 .01 3.03 3 .07 *********************** POND ROUTING *********************** DAlB-PRE ........ 25 YR ICPM Node Routing Summary 4 .01 yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :31 :01 yyyDate : 08-01-2006 y yyyType .... Executive Summary (Nodes) yyyName .... DAl -PRE -25 yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DAl .PPK yyyStorm ... 25 YR yTag: 25 YR NETWORK SUMMARY --NODES yPage 1.01 Event : 25 YR (Trun.= HYG Truncation: Blank=None; L=Left ; R=Rt ; LR=Left & Rt) Outfall ICPM CALCULATION TOLERANCES Target Convergence= Max . Iterations ICPM Time Step Output Time Step ICPM Ending Time Node ID ----------------- DAlA-PRE-25 DAlB-EX DAlB-PRE DAlB-PRE OUT DAlB-PRE-25 .000 cfs +/- 35 loops .0500 hrs .0500 hrs 7 .0000 hrs HYG Vol Qpeak Type ac-ft ---------- HYG .536 T-E 3 .171 POND 3 .171 POND 3 .171 HYG 2 .644 Trun . hrs R R .1665 .3500 .3000 .3500 . 3135 yyyS/N : HOMOL0902508 Kling Engineering & Surveying Qpeak cf s 25 .93 74 .43 80 .62 74 .43 67.97 Max WSEL ft 265 .00 269 .05 yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :31 :01 yyyDate : 08-01-2006 y yyyType .... Vol : Elev-Area yPage 2 .01 yyyName .... DAlB-PRE yyyFile .... H:\ENG I NE-l \CRESCE-1\DRAINAG E\PPK-TMP\DAl .PPK Elevation (ft) 262 .57 263 .00 264 .00 265 .00 266 .00 267 .00 268 .00 269 .00 270 .00 271 .00 272 .00 273 .00 274.00 Planimeter (sq . in) * Incremental vol ume Ar ea Al+A2+sqr(Al*A2) (sq.ft) (sq.ft) 0 0 3 3 32 45 91 177 188 410 346 789 571 1361 886 2168 1587 3659 2890 6619 4327 10753 6834 16599 11779 27585 POND VOLUME EQUATIONS Volume (ac-ft) .000 .000 .000 .001 .003 .006 .010 . 017 .028 .051 .082 .127 . 211 Volume Sum (ac-ft) .000 .000 .000 .002 .005 . 0 11 . 0 21 .038 .066 .117 .199 .326 .537 computed by the Conic Method for Reservoir Vo l umes . Volume = (1/3) * (EL2-EL1) * (Area l + Area2 +sq .rt . (Areal*Area2)) where : ELl , EL2 Areal ,Area2 Volume = Lower and upper elevations of the increment Areas computed for ELl , EL2 , respectivel y = Incremental volume between EL l and EL2 yyyS/N: HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :31 :01 yyyDate : 08 -01-2006 y yyyType .... Outletyinput Data yyyName .... EX -DA1B-SH30 yyyFile .... H:\ENGINE-1 \CRESCE-1\DRAINAGE\PPK-TMP\DAl .PPK yyyTitle ... EXISTING STRUCTURE AT SH30 REQUESTED POND WS ELEVATIONS: Min. Elev.= Increment = Max. Elev .= 262 .57 ft 1.10 ft 273.00 ft ********************************************** OUTLET CONNECTIVITY ********************************************** ---> Forward Fl ow Only (Upstream to DnStream) <---Reverse Flow Only (DnStream to Upstream) <---> Forward and Reverse Both Allowed Structure Culvert-Circular TWySETUP ,yDS Channel No . ---> Outfall El, ft TW 262.570 yyyS/N : HOMOL0902508 Kling Engineering & Surveying yPage 3 .01 E2 , ft 273 .000 yyyPond Pack Ver : 8-01 -98 (61) yyyCompute Time: 11:31 :01 yyyDate : 08-01-2006 y yyyType .... Outletyinput Data yyyName .... EX-DA1B -SH30 yyyFile .... H:\ENGINE-1\CRESCE-l\DRAINAGE\PPK-TMP\DAl .PPK yyyTitle ... EXISTING STRUCTURE AT SH30 OUTLET STRUCTURE INPUT DATA Structure ID Structure Type Culvert-Circular No . Barrels 1 Barrel Diameter 3 .0000 ft Upstream Invert 262 .57 ft Dnstream Invert 258 .00 ft Horiz . Length 117 . 00 ft Barrel Length 11 7 . 09 ft Barrel Slope .03906 ft/ft OUTLE T CONTROL DATA ... yPage 3 .02 Mannings n Ke Kb Kr HW Convergence . 0130 .5000 . 007228 1. 0000 .001 (forward entrance loss) (per ft of full flow) (reverse entrance loss) +/-ft INLET CONTROL DATA ... Equation form 1 Inlet Control K .0098 Inlet Control M 2 .0000 Inlet Control c .03980 Inlet Control y .6700 Tl ratio (HW/D) 1.141 T2 ratio (HW/D) 1. 287 Slope Factor -.500 Use unsubmerged inlet control Form 1 equ. below Tl elev . Use submerged inlet control Form 1 equ. above T2 elev . In transition zone between unsubmerged and submerged inlet control, interpolate between flows at Tl & T2 ... At Tl Elev 265 .99 ft ---> Flow 42 .85 cfs At T2 Elev= 266 .43 ft ---> Flow 48 .97 cfs yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :31 :01 yyyDate : 08-01-2006 yyyType .... ICPM Node Routing Summary yPage 4.01 Event : 25 YR yyyName .... DAlB-PRE yTag : 25 YR yyyFile .... H:\ENGINE-l \CRES CE-1\DRAINAGE\PPK-TMP\DAl.PPK yyyStorm ... 25 YR yTag : 25 YR HYG Dir Inflow HYG file Outflow HYG file Pond Node Data Pond Volume Data Pond Outlet Data No Infiltration INITIAL COND ITIONS Starting WS Elev Starting Volume Starting Outflow Pond Inflow .... . Pond Outflow ... . Pond Inflow .... . Pond Outflow ... . I CPM POND ROUTING SUMMARY H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\ DAlB-PRE IN 25 YR DAlB-PRE OUT 25 YR DAlB-PRE DAlB-PRE EX-DA1B-SH30 265 .00 ft .002 ac-ft .00 cfs CALCULATION TOLERANCES Target Convergence= Max . Iterations ICPM Time Step Output Time Step ICPM Ending Time .000 cfs +/- 35 loops .0500 hrs .0500 hrs 7 .0000 hrs MAX IMUM STORAGE Tp , hrs El ev, ft .3500 FORWARD FLOW PEAKS Tp, hrs .3000 .3500 Qp , cfs 80 .62 74 .43 269 .05 TOTAL VOLUME IN Vol , ac-ft Directi on 3 .171 .000 Forward Reverse Vol , ac-ft .039 REVERSE FLOW PEAKS Tp, hrs .0000 .0000 Qp , cfs .00 .00 TOTAL VOLUME OUT Vol , ac-ft Direction .000 3 .171 Reverse Forward MASS BALANCE (ac-ft) + Initial Vol .... . + Total Vol IN ... . -Total Vol OUT .. . -Ending Pond Vol . Difference ..... . .002 3 .171 3 .171 .002 <--(At 7 .0000 hrs Elev .= 265 .00 ft) .000 ac-ft (.000% of Inflow Volume) yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver: 8-01 -98 (61) yyyCompute Time : 11 :31 :01 yyyDate : 08-01-2006 APPENDIX 7b Detention Routing Calculations Post Development Conditions yyyTable of Contentsy i Table of Contents ******************** NETWORK SUMMARIES ********************* DA l-PST-25 ...... 25 YR Executive Summary (Nodes) 1 .01 *********************** POND VOLUMES *********************** DAlB-POST ....... Vol: Elev-Area 2 .01 DAlC-POST ....... Vol : Elev-Area 2.02 ******************** OUTLET STRUCTURES ********************* DA-18-PST ....... Out l etyinput Data ................. . Indi vidual Outlet Curves .......... . Composite Rating Curve ............ . EX -DA1B-SH30 .... Outletyinput Data ................. . Individual Outlet Curves .......... . Composite Rating Curve ............ . 3 .01 3 .04 3.32 3.46 3 .48 3.52 *********************** POND ROUTING *********************** DAlB-POST ....... 25 YR ICPM Node Routing Summary ......... . 4 .01 DAlC-POST ....... 25 YR ICPM Node Routing Summary 4 .02 yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver: 8-01-98 (61) yyyCompute Time : 11 :43:41 yyyDate : 08-01-2006 y yyyType .... Executive Summary (Nodes) yyyName .... DAl -PST-25 yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DAl .ppk yyyStorm ... 25 YR yTag: 25 YR NETWORK SUMMARY --NODES yPage 1.01 Event: 25 YR (Trun .= HYG Truncation : Blank=None; L=Left ; R=Rt ; LR=Left & Rt) Outfall yyyS/N : yyyPond y ICPM CALCULATION TOLERANCES Target Convergence= Max . Iterations ICPM Time Step Output Time Step ICPM Ending Time Node ID .000 cfs +/- 35 loops .0500 hrs .0500 hrs 7 .0000 hrs HYG Vol Type ac-ft Qpeak Trun. hrs ------------------------------------ DAlA-PST-25 HYG .431 R .1665 DAlB-EX T-E 3 .198 .3500 DAlB-POST POND 2 .767 .2000 DAlB-POST OUT POND 2 .767 .3500 DAlB-PST-25 HYG 2 .364 R .1665 DAlC-POST POND 3 .200 .2500 DAlC-POST OUT POND 3 .198 .3500 DAlC-PST-25 HYG . 438 R .1665 HOMOL0902508 Kling Engineering & Surveying Pack Ver : 8 -01 -98 ( 61) yyyCompute Time : 11 :43 :41 Qpeak Max WSEL cfs ft ----------------- 20 .82 62 .79 265 .00 121 . 72 52 .71 277 .24 114 . 24 64 .87 62 .79 267 .89 21 .15 yyyDate : 08-01-2006 yyyType .... Vol : Elev-Area yPage 2.01 yyyName .... DAlB-POST yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DAl .ppk Elevation (ft) 271.00 272. 00 273 .00 274 .00 275 .00 276 .00 277 .00 278 .00 279 .00 Planimeter (sq . in) Area Al+A2+sqr(Al*A2) (sq.ft) (sq.ft) 0 0 2235 2235 5010 10591 8129 19521 11325 29049 13685 37459 16459 45152 19727 54205 23743 65112 POND VOLUME EQUATIONS Volume (ac-ft) .000 . 017 .081 .149 .222 .287 .346 .415 . 4 98 Volume Sum (ac-ft) .000 . 017 .098 .248 .470 .756 1 .102 1. 517 2 .0 15 * Incremental volume computed by the Conic Method for Reservoir Volumes . Volume= (1/3) * (EL2-EL1) * (Areal+ Area2 +sq.rt . (Areal*Area2)) where : ELl , EL2 Areal,Area2 Volume = Lower and upper elevations of the increment Areas computed for ELl , EL2 , respectively = I ncremental volume between ELl and EL2 yyyS/N : HOMOL0902508 Kling Engineerin g & Surveying yyyPond Pack Ver : 8 -01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate: 08-01-2006 y yyyType .... Vol : Elev-Area yyyName .... DAlC-POST yyyFile .... H:\ENGINE-1\CRESCE-l \DRAINAGE\PPK-TMP\DAl .ppk Elevation (ft) 262 .57 263 .00 264 .00 265 .00 266 .00 267 .00 268 .00 269 .00 270 .00 271 .00 272 .00 273 .00 Planimeter (sq .in) Area Al+A2+sqr(Al*A2) (sq.ft) (sq.ft) 0 0 3 3 32 45 91 177 188 410 346 789 571 1361 886 2168 1348 3327 1952 4 922 2665 6898 4487 10610 POND VOLUME EQUATIONS Volume (ac-ft) .000 .000 .000 .001 .003 .006 .010 . 017 .025 .038 .053 .081 yPage 2 .02 Volume Sum (ac-ft) .000 .000 .000 .002 .005 . 011 .021 .038 .063 .101 .154 .235 * Incremental volume computed by t he Conic Met hod for Reservoir Volumes . Volume = (1/3) * (EL2-EL1) * (Areal + Area2 + sq .rt . (Ar eal*Area2)) where : ELl, EL2 = Lower and upper elevations of the incremen t Areal ,Area2 Areas computed for ELl , EL2 , respectively Volume = Incremental volume between ELl and EL2 yyyS/N: HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate : 08 -01-2006 y yyyType .... Outletyinput Data yyyName .... DA-lB-PST yyyFile .... H:\ENGINE-1\CRESCE-l\DRAINAGE\PPK-TMP\DAl .ppk yyyTitle ... lB OUTLET WORKS REQUESTED POND WS ELEVATIONS : Min . El ev .= Increment = Max . Elev .= 271 .00 ft 1. 00 ft 279 .00 ft ********************************************** OUTLET CONNECTIVITY ********************************************** ---> Forward Flow Only (Upstream to DnStream) <---Reverse Flow Only (DnStream to Upstream) <---> Forward and Reverse Both Allowed Structure Culvert-Circular Weir-Rectangular TWySETUP ,yDS Channel No . <---> <---> Outfall TW TW El, ft 271 .000 278 .000 yyyS/N : HOMOL0902508 Kling Engineering & Surveying yPage 3 .01 E2 , ft 279 .000 279 .000 yyyPond Pack Ver : 8 -01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate : 08-01-2006 y yyyType .... Outletyinput Data yyyName .... DA-lB-PST yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DAl .ppk yyyTitle ... lB OUTLET WORKS OUTLET STRUCTURE INPUT DATA Structure ID Structure Type Culvert-Circular No. Barrels 1 Barrel Diameter 2.5000 ft Upstream Invert 271.00 ft Dnstream Invert 269 .00 ft Horiz . Length 83 .00 ft Barrel Length 83 .02 ft Barrel Slope .02410 ft/ft OUTLET CONTROL DATA ... yPage 3.02 Mannings n Ke Kb Kr HW Convergence . 0130 .5000 .009217 1.0000 .001 (forward entrance loss) (per ft of full flow) (reverse entrance loss) +/-ft INLET CONTROL DATA ... Equation form 1 Inlet Control K . 0098 Inlet Control M 2 .0000 Inlet Control c .03980 Inlet Control Y .6700 Tl ratio (HW/D) 1 .148 T2 ratio (HW/D) 1. 295 Slope Factor -.500 Use unsubmerged inlet control Form 1 equ . below Tl elev . Use submerged inlet control Form 1 equ . above T2 elev . In transition zone between unsubmerged and submerged inlet control , interpolate between flows at Tl & T2 ... At Tl Elev 273.87 ft ---> Flow 27 .16 cfs At T2 Elev= 274 .24 ft ---> Flow 31 .05 cfs yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver: 8-01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate : 08-01-2006 y yyyType .... Outletyinput Data yyyName .... DA-18-PST yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\DAl .ppk yyyTitle ... 18 OUTLET WORKS OUTLET STRUCTURE INPUT DATA Structure ID Structure Type # of Openings Crest Elev . Weir Length Weir Coeff . Weir TW effects Weir-Rectangular 1 278.00 ft 45 .00 ft 3 .000000 (Use adjustment equation) yyyS/N : HOMOL0902508 Kling Engineering & Surveying yPage 3 .03 yyyPond Pack Ver : 8-01 -98 (61) yyyCompute Time : 11:43 :41 yyyDate : 08-01-2006 yyyType .... Outletyinpu t Data yyyName .... EX-DA1B-SH30 yyyFile .... H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP \DAl .ppk yyyTitle ... EXISTING STRUCTURE AT SH30 REQUESTED POND WS ELEVATIONS : Min . Elev .= Increment = Max. Elev .= 262 .57 ft 1. 10 ft 273 .00 ft ********************************************** OUTLET CONNECTIVITY ********************************************** ---> Forward Flow Only (Upstream to DnStream) <---Reverse Flow Only (DnStream to Upstream) <---> Forward and Reverse Both Allowed Structure Culvert-Circular TWySETUP ,yDS Channel No . ---> Ou tfall El, ft TW 262 .570 yyyS/N : HOMOL0902508 Kling Engineering & Surveying yPage 3 .46 E2 , ft 273.000 yyyPond Pack Ver : 8 -01 -98 (61) yyyCompute Time : 11:43:41 yyyDate: 08-01-2006 y yyyType .... Outletyinput Data yyyName .... EX -DA1B-SH30 yyyFile .... H:\ENGINE-l \CRESCE-1\DRAINAGE\PPK-TMP\DAl.ppk yyyTitle ... EXISTING STRUCTURE AT SH30 OUTLET STRUCTURE INPUT DATA Structure ID Structure Type Culvert-Circular No . Barrels 1 Barrel Diameter 3 .0000 ft Upstream Inver t 262 .57 ft Dnstr eam Inver t 258.00 ft Horiz . Length 11 7 . 00 ft Barrel Length 11 7 . 09 ft Barrel Slope .03906 ft/ft OUTLET CONTROL DATA ... yPage 3 .47 Mannings n Ke Kb Kr HW Convergence . 0130 .5000 .007228 1.0000 .001 (forward entrance loss) (per ft of full flow) (reverse entrance loss) +/-ft INLET CONTROL DATA ... Equation form 1 Inlet Control K .0098 Inlet Control M 2 .0000 Inlet Control c .03980 Inlet Control Y . 6700 Tl ratio (HW/D) 1 .141 T2 ratio (HW/D) l. 287 Slope Factor -.500 Use unsubmerged inlet control Form 1 equ . below Tl elev . Use submerged inlet control Form 1 equ . above T2 elev . In transition zone between unsubmerged and submerged inlet control , interpolate between flows at Tl & T2 ... At Tl Elev 265 .99 ft ---> Flow 42 .85 cfs At T2 El ev= 266 .43 ft ---> Flow 48 .97 cfs yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate : 08-01-2006 yyyType .... ICPM Node Routing Summary yPage 4 .01 Event : 25 YR yyyName .... DAlB -POST yTag : 25 YR yyyFil e .... H:\ENGINE-l \CRESCE-1\DRAINAGE\PPK-TMP\DAl .ppk yyyStorm ... 25 YR yTag : 25 YR HYG Di r Inflow HYG file Outfl ow HYG file Pond Node Data Pond Volume Data Pond Outlet Data No Infiltration INITIAL CONDITIONS Starting WS Elev Starting Volume Starting Outflow Pond Inflow .... . Pond Outflow ... . Pond Inflow .... . Pond Outflow ... . ICPM POND ROUTING SUMMARY H:\ENGINE-l\CRESCE-1\DRAINAGE\PPK-TMP\ DAlB-POST IN 25 YR DAlB-POST OUT 25 YR DAlB -POST DAlB -POST DA -18-PST 271.00 ft .000 ac-ft .00 cfs CALCULATION TOLERANCES Target Convergence= Max . Iterations ICPM Time Step Output Time Step ICPM Ending Time .000 cfs +/- 35 loops .0500 hrs .0500 hrs 7 .0000 h rs MAXIMUM STORAGE Tp, hrs Elev, ft .3500 FORWARD FLOW PEAKS Tp , hrs .2000 .3500 Qp , cfs 121 .72 52 .71 277 .24 TOTAL VOLUME IN Vol , ac-ft Direction 2.767 .000 Forward Reverse Vo l, ac-ft 1. 203 REVERSE FLOW PEAKS Tp , hrs .0000 .0000 Qp , cfs .00 .00 TOTAL VOLUME OUT Vol, ac-ft Direction .000 2. 7 67 Reverse Forward MASS BALANCE (ac-ft) + Initial Vol .... . + Total Vol IN ... . -Total Vol OUT .. . -Ending Pond Vol. Difference ..... . .000 2 .767 2 .767 .000 <--(At 7 .0000 hrs Elev .= 271 .00 ft) -.000 ac-ft (.003% of Outflow Volume) yyyS/N : HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver: 8-01-98 (61) yyyCompute Time : 11:43:41 yyyDate: 08-01-2006 y yyyType .... ICPM Node Routing Summary yPage 4 .02 Event : 25 YR yyyName .... DAlC-POST yTag : 25 YR yyyFile .... H:\ENGINE-l\CRESCE-1 \DRAINAGE\PPK-TMP\DAl .ppk yyyStorm ... 25 YR yTag : 25 YR HYG Dir Inflow HYG file Outflow HYG file Pond Node Data Pond Vol ume Data Pond Outlet Data No Infil tration ICPM POND ROUTING SUMMARY H:\ENGINE-1 \CRESCE-l \DRAINAGE\PPK-TMP\ DAlC-POS T IN 25 YR DAlC-POS T OUT 25 YR DAlC-POS T DAlC-POS T EX-DA1B-SH30 INITIAL CONDITIONS CALCULATION TOLERANCES Starting WS Elev Starting Volume Starting Outflow Pond Inflow ..... Pond Ou tflow .... Pond Inflow ..... Pond Outflow .... 262.57 ft .000 ac-ft .00 cfs Target Convergence= Max . Iterations ICPM Time Step Output Time Step ICPM Endi ng Time .000 cfs +/- 35 loops .0500 hrs .0500 hrs 7 .0000 hrs MAXIMUM STORAGE Tp, hrs Elev, ft Vol , ac-ft .3500 267 .89 .020 FORWARD FLOW PEAKS REVERSE FLOW PEAKS Tp, hrs Qp , cfs Tp, hrs Qp , cf s ------------------------------------ .2500 64 .87 .0000 .00 .3500 62 .79 .0000 .00 TOTAL VOLUME IN TOTAL VOLUME OUT Vol, ac-ft Direction Vol, ac-ft Direction -------------------------------------- 3.200 Forward .000 Reverse .000 Reverse 3 .198 Forward MASS BALANCE (ac-ft) + Initial Vol .... . + Total Vol IN ... . -Total Vol OUT .. . -Ending Pond Vol . Difference ..... . .000 3 .200 3 .198 .002 <--(At 7 .0000 hrs Elev.= 265 .00 ft) -.000 ac-ft (.001% of Inflow Volume) yyyS/N: HOMOL0902508 Kling Engineering & Surveying yyyPond Pack Ver : 8-01-98 (61) yyyCompute Time : 11 :43 :41 yyyDate : 08 -01-2006