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HomeMy WebLinkAbout33 Brazos Valley Bank 04-13 4038 SH 6 SI DEVELOPMENT PERMIT PERMIT NO . 04-13 ~-~ couua STATION Project: BRAZOS VALLEY BANK-TEMPORARY BUILDING FOR AREAS OUTSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: Graham Corner Plaza Block 1 Lot 1 DATE OF ISSUE: OWNER: Brazos Valley Bank Building Group , Ltd c/o Ted Whitmer 2508 Merrimic Court College Station , Texas 77845 SITE ADDRESS: 4102 State Highway 6 South DRAINAGE BASIN: Lick Creek VALID FOR 9 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 required to remain is also prohibited . TCEQ PHASE II RULES IN EFFECT 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 . 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 C ity 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 Brazos Valley Bank Phase i' College Station, Texas Developer: Braz os Valley Bank Building Group , Ltd. 2508 Merrimac Court , C ollege Station, Texas 77845 (979) 764-2667 Prepared B v : TEXCO,N General Qontractor 1'7 07 Graham Road C oll e ge Station , Tex as 7 7 845 (979) 794-7743 CERTIFICATION I, Joseph P . Schultz, Licensed Professional Engineer No. 65889, State of Texas, certify that this report for the drainage design for the Brazos Valley Bank, Phase 1 in College Station, Texas, was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof, with the exception that storm water runoff detention is not being required for this project since the site discharges directly into an existing storm sewer system and then immediately into the 100-year floodplain limits. TABLE OF CONTENTS-REVISED 41112004 BRAZOS VALLEY BANK, PHASE 1 CERTIFICATION .................................................................................................................................................................. 1 TABLE OF CONTENTS ........................................................................................................................................................ 2 LIST OF TABLES .................................................................................................................................................................. 2 INTRODUCTION ................................................................................................................................................................... 3 GENERAL LOCATION AND DESCRIPTION .................................................................................................................. 3 FLOOD HAZARD INFORMATION .................................................................................................................................... 3 DEVELOPMENT DRAINAGE P ATTERNS ....................................................................................................................... 3 DRAINAGE DESIGN CRITERIA ........................................................................................................................................ 3 STORM WATER RUNOFF DETERMINATION ............................................................................................................... 3 STORM SEWER PIPE & GRATE INLET DESIGN .......................................................................................................... 3 CONCLUSIONS ..................................................................................................................................................................... 5 APPENDIX A .......................................................................................................................................................................... 6 Calculations EXHIBIT A ............................................................................................................................................................................ 14 Post Development Drainage Area Map LIST OF TABLES TABLE 1 -Rainfall Intensity & Runoff Data -REVISED 41112004 ...................................................... 3 2 DRAINAGE REPORT-REVISED 41112004 BRAZOS VALLEY BANK, PHASE 1 INTRODUCTION The purpose of this report is to provide the hydrological effects of the construction of the parking area and temporary building for Phase 1 of the Brazos Valley Bank, which is on Lot l , Block 1 of the Graham Comer Plaza project. This report will also show that th e storm water runoff generated by this project will be collected by a storm sewer system that ties into the existing storm sewer system constructed with the Graham Comer Plaza Subdivision project. The existing storm sys tem was designed for fully developed conditions , so there should be minimal offsite or downstream impact due to the construction of this project. GENERAL LOCATION AND DESCRIPTION The project is located on Lot 1, Block 1 of the Graham Comer Plaza development (2.48 acres) located in College Station, Texas. The site is open land with grass. The existing ground elevations range from elevation 286 to elevation 289. The general location of the project site is shown on the vicinity map in Exhibit A. FLOOD HAZARD INFORMATION The project site is loc ated in the Lick Creek Drainage Basin. The site is located in a Zone X Area according to the Flood Insurance Rate Map (FIRM) prepared by the Federal Emergency Management Agency for Brazos County, Texas and incorporated areas dated February 9, 2000, panel number 48041C0201 D. Zone X Areas are determined to be outside of the 500-yr floodplain. This site is not within the limit of study for the FIRM. However, the approximate 100-year floodplain limits and the floodway were previously determined by Robertson Engineering for the C ity of College Station, and these limits were included on the Final Plat for the project. None of the floodplain area is located on this site . DEVELOPMENT DRAINAGE PATTERNS The storm water runoff from this site is collected by the existing storm sewer system and then discharged into the North Fork of Lick Creek and the 100-year floodplain ; therefore , no detention is required for this project. The drainage area boundaries are shown on Exhibit A. DRAINAGE DESIGN CRITERIA The design parameters for the storm sewer are as follows : • The Rational Method is utili zed to determine peak stonn water runoff rates for the sto1111 sewer desi gn. • Design Storm Fre qu e nc y Storm sewe r system , ' I 0 and 100 -yea r s torms eve nt s • Runoff Coefficients Undeveloped areas Developed areas c = 0.30 c = 0.85 • Rainfall Intensity equations and values for Brazos County can be found in Table l. • Time of Concentration, tc -Since these are smaller drainage areas, a minimum tc of 10 minutes is used to determine the rainfall intensity values. STORM WATER RUNOFF DETERMINATION The peak runoff values were determined in accordance with the criteria presented in the previous section for the 10-, 25-and 100-year storm events. The runoff coefficients are based on the development of this tract. The drainage areas are shown in Exhibit A. Runoff conditions are summarized in Table 1. TABLE 1 -Rainfall Intensity & Runoff Data -REVISED 41112004 Area c 10 year storm 25 year storm 100 year storm le Area# (acres) 110 010 l2s 02s 1100 A1 A2 ~ C1 C2 C3 Crotal Total (min) (in/hr) (cfs) (in/hr) (cfs) (in/hr) ·201 2 .27 2.27 0 .85 0 .85 10 8.635 16 .66 9 .861 19 .03 11 .639 1 0 .29 0 .29 0 .85 0 .85 10 8.635 2.13 9 .861 2.43 11 .639 2 0 .23 0 .61 0 .84 0.85 0.3 0.45 10 8 .635 3 .27 9 .861 3.73 11 .639 .. 2 0.84 0.84 0.85 0.3 0.30 10 8.635 2.18 9.861 2.49 11.639 3 0 .24 0 .24 0 .85 0 .85 10 8.635 1.76 9 .861 2 .01 11 .639 4 0.41 0.49 0 .90 0 .85 0 .3 0 .55 10 8.635 4 .28 9.861 4 .89 11 .639 .. 4 0.9 0.90 0.85 0.3 0.30 10 8.635 2.33 9.861 2.66 11 .639 ·201 1.07 1.07 0 .85 0 .85 10 8.635 7 .85 9.861 8 .97 11 .639 . Refer to Graham Comer Plaza Drainage Report for more 1nformat1on . •• Calculated using undeveloped conditions for the entire drainage area to evaluate drainage for Phase 1 construction. The Rational Method: Q = CIA I = b I (ic+d)0 Q =Flow (cfs) tc; =Time of concentration (min) A= Area (acres) C = Runoff Coeff. I = Rainfall Intens ity (in/hr) Brazos County: 10 year storm b = 80 d = 8 .5 e = 0.763 25 year storm b = 89 d = 8 .5 e = 0 .75 100 year storm b = 96 d = 8 .0 e = 0 .730 STORM SEWER PIPE & GRATE INLET DESIGN tc = U(V*60) L = Length (ft) V = Velocity (fVsec) This project consists of the construction of th e p arking area, storm sewer system and th e temporary building that is proposed for th is site . The private stom1 sewer syst em wi ll co llect the runoff for this development , as well as the d eve lop m e nt of Phase 2. T he proposed stom1 sew e r sys tem w ill tie int o th e ex is ting pri va te storm sewer system a nd d isc harge it into th e No rth Fork of Li ck C reek. T he prop osed s torm sewe r pip e system is d es ig n e d for both the Phas e 1 co ns tru ct io n as we ll as the future d eve lo ped co nditi o n of Lo t I , Block I , which w ill occur with th e -l 0 100 (cfs) 22.46 2.87 4.41 2.93 2 .37 5 .77 3.14 10 .59 construction of Phase 2 at a later time . Grate inlets will collect the runoff from th e Phase 1 development, and the proposed storm sewer pipes will tie into the existing Pipe 2 (refer to the Graham Comer Plaza Drainage Report, July 2003 ). Pipes 6 & 10 will be constructed and the ends plugged until the construction of Phase 2. The runoff from the Phase 2 area will be collected by the Phase 1 area inlets until the remainder of the storm sewer system is constructed with Phase 2. As previously stated, the storm water runoff from this site will be collected by th e proposed storm sewer system, which ties into the e x isting storm system, which flow s dire ctly into the North Fork of Lick Creek . The storm sewer piping for this proj ec t has been selected to be Reinforced Concrete Pipe (RCP) meeting the requirements of ASTM C-76, Class III pipe meeting the requirements of ASTM C-789 for the 24" and 30" diameter pipes. The 15 " and 18" pipe material will be A-2000 corrugated PVC pipe or HDPE pipe. The grate inlets in the pavement areas and the junction box will b e cast-in- place or pre-cast concrete. The proposed storm sewer grate inlets were sized using the orifice equation, solv ing for the cle ar opening area: Q = 4.82 *Ag* y 112 ¢ Ag= QI (4.82 * y 112 ) where Q = capacity, cfs Ag = clear opening area, sq. ft . y = total depth of water on the inlet, ft . The capacities of the grate inlets were reduced by 50% for clogging. Data perta ining to inlet sizes and design calculations are summarized in Appendix A. The grate inlets were designed for a maximum depth of 6" for the 10-year storm event. There are no curb inlets proposed for this development. Appendix A contains a summary of the storm sewer pipe design parameters and calculations, including a summary of the flows through the storm sewer system for the 10 and 100-year events. All pipes are 15" in diameter or larger. The pipes for the storm sewer system were designed based on the 10-year storm event, and they will also pass the 100-year storm event. The velocity of flow in the storm sewer pipe system is not low e r than 2.5 feet per second, and it does not exceed 15 feet per second. As the data s ho w s, even during low flow conditions, the velocity in the pipes will exceed 2 .5 fe et p e r s econd and prevent sediment build-up in the pipes . The maximum flow in the storm s ewer pipe system will occur in Pipe No. 5 . The maximum velocity for the pipe s ystem in thi s development will be 8 .3 feet per second and will occur in Pipe No . 6 (once Phase 2 is constructed). Refer to Appendix A for calculations and data . CONCLUSIONS T h e con s tru c ti o n of thi s proj ect w ill increa s e th e sto rm w a ter runoff fro m thi s s it e. Ho w e v e r, th e runo ff w ill be c oll e cte d b y th e prop o sed sto1111 sew e r sys te m , con nec t to th e ex is tin g s to rm sew e r s ys te m , a nd di sch a r ge into the I 00 -year floodpl a in . T he in c re as ed fl ow in thi s tribut a r y s ho uld no t h ave a s ig nifi cant imp ac t o n th e s urro un d in g pro pe rt y. o fl oo d d a m a ge to dow n s tr ea m o r a dj acen t la nd ow n e rs is ex pec ted as a res ult o f thi s deve lo p m e nt. APPENDIX A Calculations Brazos Valley Bank Phase 1 Grate Inlet Summary -REVISED 41112004 Q = 4 .82 * Ag * y 112 ¢ y = (QI (4 .82 * Ag))2 Whe re : Q = flow at inlet, cfs Ag = open area of inlet, f t2 y = depth at inlet, ft Conditions for Development of Phases 1 & 2 : Inlet Actua l Inlet Model Grate Size Ag Number number (in x in) in2 3 V-5 728 26 x 26 370 .0 4 V-5728 26 x 26 370 .0 ign A., 10-Year Storm Des 50 % c logging Q10 Depth , y in2) (cfs) (ft) (in) 85.0 2 .13 0 .12 1.4 85 .0 1.76 0 .08 1.0 Conditions for Development of Phase 1 only (Pipes 6 & 10 plugged): Des Inlet Grate Size Actual Inlet Model Ag Number number ig n A., 10-Year Storm logging Q10 Depth , y 50 % c (in x in) in2 in2) {cfs) (ft) (in) 3 V-572 8 26 x 26 370 .0 85.0 4.31 0.48 5.8 ------ 4 V-572 8 26 x 26 370 .0 85.0 4.09 0.44 5.2 d Area 4 (undeveloped), and Note: Runoff to tals for Inlet 3 in clu de run off from Area 3 (deve loped) an Runoff totals for Inlet 4 in clude runoff from Area 1 (developed) and Are a 2 (unde veloped). - II 100-Year Storm Q1 00 Depth , y (cfs) (ft) (i n) 2 .87 0 .21 2 .6 -- 2 .37 0 .15 1.8 100-Year Storm 0 100 Depth , y (cfs) (ft) (in ) 5.80 0.88 10.5 ------- 5.51 0.79 9.5 Brazos Bank Phase 1 Pipe Calculations Pipe# Size Length Slope (in) (ft) (%) 2 (Exi sting) 30 167 .5 0 .70 5 30 51 .8 0 .70 ---- 6 24 87 .3 1.40 --- 9 18 160.8 1.10 - 10 15 87 .5 0 .60 Pipe 2 0 10 Area 201 , 207 0 25 Area 201 , 207 0 100 Area 201 , 207 Pipe 6 0 10 Area 207, 2 0 25 Area 207 , 2 0 100 Area 207, 2 Pipe 10 0 10 Area 4 0 25 Area 4 0 100 Area 4 Inlet Outlet Invert Elev Invert Elev (ft) (ft) 277 .45 276 .28 277 .96 277.60 279 .68 278.46 280.73 278 .96 281 .50 280 .98 = 24 .51 28.00 33 .04 = 11 .12 12 .70 14.99 = 4 .28 4 .89 5.77 10-year storm 100-year storm 0 10 V10 Travel Time, lno 0100 V100 Travel Time , tnoo %Full %Full (cfs) (fps) (sec) (min) (cfs) (fps) (sec) (min) 24.51 7 .2 65.8 23 0 .39 33 .04 7.4 85 .7 23 0 .38 19.29 6 .8 56 .1 8 0 .13 26 .00 7 .2 68 .6 7 0.12 11 .12 7 .7 46.9 11 0 .19 14 .99 8 .3 56 .0 11 0 .18 6 .04 6.0 55 .3 27 0 .45 8 .14 6.4 67.4 25 0.42 4.28 4.9 67 .0 18 0 .30 5 .77 5.0 89 .7 18 0 .29 Pipe 5 010 Area 207 , 1, 2 , 3, 4 = 19 .29 0 25 Area 207 , 1, 2 , 3, 4 22 .03 0 100 Area 207 , 1, 2 , 3 , 4 26 .00 Pipe 9 0 10 Area 3, 4 6 .04 0 25 Area 3 , 4 = 6 .90 0 100 Area 3 , 4 8 .14 Pipe 2 -10 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 30.0000 in 24.5100 cfs 0.0070 ft/ft 0 . 0140 19.7309 in 4.9087 ft2 3.4234 ft2 56 .7501 in 94.2478 in 7.1596 fps 8.6866 in 65.7698 % 31.8662 cfs 6 .4917 fps Pipe 2 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ....................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flo w velocity ............. . Brazos Valley Bank , Phase 1 College Station, Texas Circular Depth of Flow 30.0000 in 33.0400 cfs 0.0070 ft/ft 0.0140 25.7185 in 4.9087 ft2 4.4792 ft2 71. 0042 in · 94 .2478 in 7.3763 fps 9.0841 in 85.7285 % 31. 8662 cfs 6 .4917 fps Pipe 5 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 30.0000 in 19 .2900 cfs 0 .0070 ft/ft 0 .0140 16.8414 in 4.9087 ft2 2.8370 ft2 50.8160 in 94.2478 in 6.7994 fps 8.0394 in 56.1379 % 31.8662 cfs 6.4917 fps Pipe 5 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter . , .................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Bra z os Va lle y Ba n k , Ph ase 1 Co lleg e S t a t io n , Te x a s Circular Depth of Flow 30.0000 in 26.0000 cfs 0.0070 ft/ft 0 . 0140 20.5949 in 4.9087 ft2 3.5924 ft2 58. 5910 in 94.2478 in 7 .2 376 fps 8 .8290 in 68.6498 % 31.8662 cfs 6.4917 fps Pipe 6 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results : Depth .......................... . Area ............................ . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24 .0000 in 11.1200 cfs 0 . 0140 ft/ft 0. 0140 11.2490 in 3.1416 ft2 1.4457 ft2 36 .1962 in 75.3982 in 7.6917 fps 5.7515 in 46 .8709 % 24.8552 cfs 7.9117 fps Pipe 6 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Brazos Valley Bank, Phase 1 College Station, Te xas Circular Depth of Flow 24.0000 in 14.9900 cfs 0. 0140 ft/ft 0.0140 13 . 4418 in 3.1416 ft2 1. 8105 ft2 40.5897 in 75.3982 in 8.2794 fps 6.4232 in 56 .0 074 % 24.8552 cfs 7. 9117 fps Pipe 9 -10 Year Stor m Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Circular Depth of Flow 18.0000 in 6.0400 cfs 0.0110 ft/ft 0. 0140 Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 . 9491 in Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraul i c Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . 1 .7671 ft2 1.0020 ft2 30.1760 in 56.5487 in 6.0280 fps 4 .7815 in 55 . 2726 % 10.2301 cfs 5 .7891 fps Pipe 9 -100 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full f l o w F l owr ate ............. . Full f low ve l oci t y ............. . Brazos Valle y Bank, Phase 1 College Station, Texas Circular Depth of Flow 18 .0000 in 8 .1400 cfs 0 .0110 ft/ft 0. 0140 12.1306 in 1. 7671 ft2 1.2669 ft2 34 .6692 in 56 .5487 in 6.4254 fps 5.2619 in 67.3922 % 10 .23 01 cfs 5.7891 fp s Pipe 10 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ~ .............. . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 15 .0000 in 4.2800 cfs 0.0060 ft/ft 0.0120 10.0523 in 1.2272 ft2 0 .8742 ft2 28. 7705 in 47.1239 in 4.8957 fps 4.3756 in 67.0151 % 5.4207 cfs 4.4172 fps Pipe 10 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for ............ ~ ....... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter . , ..................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Brazos Valle y Ban k , Ph ase 1 College Stati o n, Texas Circular Depth of Flow 15.0000 in 5.7700 cfs 0.0060 ft/ft 0.0120 13. 4589 in 1 .2272 ft2 1.1607 ft2 37 .3353 in 47.1239 in 4 . 9710 fps 4.4769 in 89.7262 % 5 .420 7 cfs 4 .4172 fps EXHIBIT A Post Development Drainage Area Map 14 Design Report Waterline Fire Flow Analysis for Brazos Valley Bank -Phase 1 College Station, Texas March 2004 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 690-7711 1.0 INTRODUCTION & DESCRIPTION The purpose of this report is to provide a description of the existing waterlines located at the Graham Comer Plaza Subdivision, and to provide the results of the analysis of these waterlines under fire flow conditions . An existing 24" waterline is located along SH 6 frontage Road adjacent to the project site. Also, there is an existing 12" waterline located along Graham Road and an existing 8" waterline through the subdivision along the existing private driveway. The existing waterlines and fire hydrants will be us ed to meet the fire flow requirements for the Braz os Valley Bank -Phase l project. This project will consist of a temporary bank office building to be located on a portion of Lot l of the Graham Comer Plaza Subdivision. The office building will be a modular structure, 2,940 sf in size, that will be placed on a concrete slab at the site and removed once the permanent office building is constructed with Phase 2 of the project. 2.0 FIRE FLOW REQUIREMENTS The flow required for fire hydrant flow for the commercial site is 2,500 gallons per minute (gpm), as required by the BCS Unified Design Guideline Manual. For this analysis, we have assumed that the flow comes from two hydrants. Due to the small size of the proposed structure a separate analysis was performed using a fire flow of 1,500 gpm for Fire Hydrant No. 1. This is the fire hydrant closest to the proposed structure. The 2000 International Fire Code requires a minimum fire flow of 1,500 gpm for commercial buildings . 3.0 WATERLINE SYSTEM ANALYSIS The waterline system was analyzed using the WaterCAD computer program developed by Haestad Methods, Inc. Exhibit "l" is a schematic of the proposed waterlines , which shows the locations of the fire hydrants. The residual pressure in the existing 24" waterline was determined by calculating the headless at a flow of 2,500 gpm for the existing line . Exhibit "2" presents the results of a pressure/flow test from fire hydrants connected to the existing 12" waterline on Graham Road . A static pressure of l 00 psi and a residual pressure of 98 psi with the hydrant flow at l, 175 gpm were determined by College Station Public Utility personnel. The residual pressure of 91.9 psi at a flow of 2,500 gpm was calculated using the following eq uation: Where: QR = Q ava ilable @ desired resid ua l pressure Q F = Q during fir e flow test HR = pressure drop to desired resid ual press ur e H1 =pressure drop during fir e flow test T hi s res ult s in a residual press ur e of 9 1.9 ps i w here the ex is tin g 12" wa te rlin e co nn ec ts to the 24" wa te rlin e. The hydr a uli c g rade was se t at thi s pressure at thi s loca ti on. The computer model was run with a fire flow of 1,250 gpm at each of the existing fire hydrants for this project. The lowest residual pressure occurred in the system with this flow at fire hydrant No. 1 (Junction J-5) and fire hydrant No . 2 (Junction J-11). The pressure at this point is estimated by the model to be 90.9 psi, which exceeds the minimum of 20 psi required by the TCEQ regulations . The slight drop in pressure is due to the proximity of the fire hydrants to the 24" waterline, and also that the 8" waterline is "looped" between the 12" and 24" waterline. Exhibit "3" is a summary of the pipe system junction nodes for this scenario. Exhibit "4" is a summary of the pipe sections for the system under this demand scenario . The maximum velocity for the 8" water mains is 9 .0 feet per second, and occurs in Pipe P-12. Minor losses were not considered in the analysis as they were not deemed to be significant. The computer model was also run with a fire flow of 1,500 gpm at Fire Hydrant No. 1. The lowest residual pressure is estimated by the model to be 91.4 psi, which exceeds the minimum of 20 psi required by the TCEQ regulations. Exhibit "5" is a summary of the pipe system junction nodes for this scenario. Exhibit "6" is a summary of the pipe sections for the system under this demand scenario. The maximum velocity for the 8" water mains is 5.8 feet per second, and occurs in Pipe P-5. The calculations for the domestic water demand for this project are shown on Exhibit "7". A 5/8" water meter should be adequate for the demand of20 gpm. This flow was not included in the Fire Flow Analysis because it is not significant. 4.0 CONCLUSIONS The waterlines proposed for this development should adequately provide the fire flow required with acceptable values for headloss and velocity. This analysis was done assuming adequate residual pressure in the existing 24" water main based on the flow test data presented in Exhibit "2". A separate analysis should be performed for the Phase 2 development and for any other development in this subdivision. 2 P-4 J-4 P-5 Ti tl e : Brazos Valley B ank -Phase 1 c:ll1aestad\wtrc\bra zos-bank-ph 1 _wed Scenario: Base R-1 P-1 -FH~ / FH ~, -5 P-6 J-6 P -9 J -9 TEX CON G E NERAL CONTRAC TOR S P-1 3 J-1 0 P -1 1 P -1 0 J-1 2 P -1 2 Project Engineer : JOE SCHULTZ WaterCAD v 3_ 1 i 071cl 03124104 0 1 :4 6 :5 1 PM © H aesta d M e thods. In c _ 37 Broo ks ide Road Waterbury . CT 06708 USA (203 ) 755-1666 P age 1 o f 1 , 03/01/2004 13 : 01 FAX 979 764 3452 COLLEGE STATIO N PUB .UTL . ~rtlfl!Em[J!JJUl1tn Community Owned Date: 27 FEB 04 1601 GRAHAM ROAD COLLEGE STATION TEXAS 77845 Number pages including cover sheet - 1 Fax to: 764-7759 Attention: JOE SCHULTZ Company: TEXCON From: Butch Willis Water Wastewater Division Phone: 979-764-3435 Fax: 979-764-3452 FLOW TEST REPORT Location: GRAHAM AT IDGHWA Y 6 FEEDER Flow hydrant number: Q-151 Pitot reading: 90 (GPM): 1175 Static hydrant number: Q-121 Static PSI: 100 Residual PSI: 98 @001 Node Elevation Demand Label (ft ) Type J -1 283 .00 demand J-2 2 83.00 demand J -3 283 .00 demand J-4 283.00 demand J-5 280.50 demand J-6 280 .50 demand J -7 280 .00 demand J-8 280.00 demand J-9 280 .00 demand J-10 280 .00 demand J-11 280 .00 demand J-12 278.00 demand Titl e : Brazos V a lle y B ank -Ph ase 1 c:\ha estad l wtrc\b razo s-bank-ph 1 .w ed Demand (gpm) 0 .00 0 .00 0 .00 0 .00 1 ,250 .00 0 .00 0.00 0 .00 0 .00 0 .00 1,250 .00 0 .00 03/24 /04 10 : 1 8 :30 AM © Haes ta d Me t11ods. Inc . Scenario: Base Steady State Analysis Junction Report Demand Calculated Hydraulic Pressure Pattern Demand Grade (psi) (gpm) (ft) Fixed 0 .00 494 .84 91 .61 Fixed 0 .00 494.79 91.58 Fixed 0 .00 494.73 91 .56 Fixed 0 .00 494 .21 91 .33 Fi xed 1 ,250.00 490 .59 9.0.85 Fixed 0 .00 490 .60 90.85 Fixed 0 .00 490 .66 91 .10 Fixed 0 .00 490.70 91.11 Fixed 0 .00 490 .76 91 .14 Fixed 0 .00 490 .78 91 .15 Fixed 1,250.00 490 .80 91.16 Fixed 0 .00 494 .92 93 .80 TEXC ON GENERAL CONTRA CTORS 37 Brookside Roa d Wa te rbury. CT 06708 USA Proj ect E ngin eer : JOE SC H ULTZ W a le rC AD v3 . 1 [07 1 c l (203 ) 755-1666 Page ·1 o t I Analysis Results Scenario: Base Steady State Analysis Title: Brazos Valley Bank -Phase 1 Project Engineer: JOE SCHULTZ Project Date : 03/24/04 Comments : Scenario Summary Label Base Demand Alternative Base-Average Daily Physical Alternative Base-Physical Initial Settings Alternative Base-Initial Settings Operational Alternative Base-Operational Age Alternative Base-Age Alternative Constituent Alternative Base-Constituent Trace Alternative Base-Trace Alternative Fire Flow Alternative Base-Fire Flow Liquid Characteristics Liquid Water at 20C(68F) Specific Gravity 1 .00 Kinematic Viscosity O .108e-4 ft'/s Network Inventory Number of Pipes 13 Number of Tanks 0 Number of Reservoirs 1 -Constant Area : 0 Number of Junctions 12 -Variable Area : 0 Number of Pumps 0 Number of Valves 0 -Constant Power: 0 -FCV's : 0 -One Po int (Design Point): 0 -PBV's : 0 -Standard (3 Point): 0 -PRV's : 0 -Standard Extended : 0 -PSV's : 0 -Custom Extended: 0 -TCV's: 0 -Multiple Point: 0 Number of Spot Elevations 0 Pipe Inventory Total Length 8 in 12 in 1,773.00 ft 786.00 ft 347 .00 ft 24in Pipes @ 0.00 hr Label StatusConstituent Flow Velocity From To (mg/I) (gprn) (ftls) Grade Grade (ft) (ft) P-1 Open NIA 1,086 .21 3 .08 -95.00 -94 .84 P-2 Open NIA 1,086.21 3 .08 -94.84 -94 .79 P-3 Open NIA 1,086 .21 3 .08 -94 .79 -94 .73 P-4 Open NIA 1,086.21 3 .08 94 .73 -94.21 P-5 Open NIA 1,086 .21 6 .93 94 .21 -90 .59 P-6 Open NIA -163.79 1.05 90 .59 90 .60 P-7 Open NIA -163 .79 1 05 90 .60 90 .66 P-8 Open NI A -163 .79 1.05 -90 .66 90 .70 P-9 Open N/A -163.79 1.05 90 .70 90 .76 P-10 Open N/A -163 .79 1.05 90.76 90 .78 640.00 ft Friction Minor Total Headless Loss Loss Headlosa3radient (ft) (ft) (ft) (ft/1 OOOft) 0 .16 0 .00 0.16 2 .28 0 .05 0 .00 0 .05 2 .28 0 .05 0 .00 0 .05 2.28 0 .52 0 .00 0.52 2 .28 3 .62 0 .00 3 .62 16.44 0 .3e-2 0 .00 0 .3e-2 0 .50 0 .06 0 .00 0 .06 0 .50 0.04 0 .00 0 .04 0 .50 0 .06 0 .00 0 .06 0 .50 0 .03 0 .00 0 .03 0 .50 Proj ect Enginee r : JOE SC HULTZ Ti ll e: Bra zos Va ll ey Bank -Ph ase 1 c :\ha es tad \wlrc\brazos-ba nk-ph 1. wed TEX CON GENERAL CONTRACTORS WalerCAD v3 .1 1071 c) 0312 4 104 10 :20 :40 AM © Haes tad Me th ods. In c . 37 Broo kside Road Waterbury. CT 06708 USA (203) 755-1660 Page 1 o r 2 fx_ k: it:+" 4" I .-F <- Pipes @ 0 .00 hr Analysis Results Scenario: Base Steady State Analysis Label StatusConstituent Flow V e locity Fro m To Friction Minor Total Headless (mg/I) (gpm) P-11 Open NIA -163 .79 P-12 Open NIA 1,413.79 P-13 Open NIA 1,413 .79 Titl e : Brazos V a ll ey Bank -Pha se 1 c:\h aesta d \wtrclb ra z os-ba nk-ph 1 . wed (ft/s) G rade Grade Loss Loss Headlos!Gradien t (ft) (ft) (ft) (ft) (ft) (ft/1 OO Oft) 1.05 -90 . 78 ·90 .80 0 .0 1 0 .00 0 .01 0 .50 9 .02 ·90.80 ·94 .92 4 .12 0.00 4 .12 26.77 1.00 ·94 .92 ·95.00 0 .08 0.00 0 .08 0.13 TEXCON GENERAL CONT RACTORS 03/24 /04 10 :2 0 :40 AM © H aes tad M e ll1o d s . In c . 3 7 Broo ksicl e Road W a te rbury . CT 06 708 U S A E-1h:{,:rf--('4" Pro j ect Engineer : JOE SCHULTZ W a te rC A D v3 .1 (07 1c ) (203 ) 7 55-1666 P age 2 o f 2 Zof 2- No de Elevation Demand Label (ft) Type J-1 283 .00 demand J -2 283.00 demand J-3 283 .00 demand J-4 283 .00 demand J-5 280.50 demand J-6 280 .50 demand J-7 280.00 demand J -8 280 .00 demand J-9 280 .00 d emand J-10 280 .00 dema nd J-11 280 .00 demand J-12 278.00 d ema nd T itl e : Brazos Va ll ey Bank -Phase 1 c:\haes tad\wtrc\b razos -bank-ph 1. wed Demand (gpm ) 0 .00 0.00 0 .00 0 .00 1 ,500.00 0 .00 0 .00 0.00 0 .00 0 .0 0 0 .00 0 .0 0 03/2 4104 10 :25 : 13 AM © Haestad M e th od s . In c. Scenario : Base Steady State Analysis Junction Report Demand ~alculated Hydraulic Pressu re Pattern Demand Grade (psi ) (gpm) (ft) Fixed 0.00 494.89 91.63 Fixed 0 .00 494.85 9 1 .6 1 Fixed 0 .00 494 .81 91 .59 Fixed 0 .0 0 494.44 91.43 Fixed 1,500.0 0 491 .88 91.41 Fixed 0.00 491 .92 91.42 Fixed 0 .0 0 492.62 91 .95 Fixed 0.00 493 .03 92.12 Fixed 0 .0 0 493.70 92.41 Fixed 0 .00 493.99 92 .54 Fixed 0 .00 494.14 92 .6 0 Fixed 0 .00 494.98 93 .83 " \\ s Project Engineer: JOE SC HU LTZ TEXCON GENERAL CONTRACTORS Wate rCAD v3 .1 [071cJ 37 Broo ks id e Road Wa te rbury. CT 06708 USA (203 ) 755-16 6 6 Page 1 o f 1 Analysis Results Scenario: Base Steady State Analysis Pipes @ 0 .00 hr Label Status Co nstituent Flow Velocity From To Friction Minor Total Head loss (mg/I) (gpm) (ft/s ) Grade G rade Loss Loss Headloss Gra d ient (ft) (ft) (ft) (ft) (ft) (ft/1 OOOft) P-1 Open N/A 900 .43 2 .55 495.00 494.89 0 .11 0 .00 0 .11 1.61 P-2 Open N/A 900.43 2 .55 494 .89 494 .85 0 .04 0.00 0.04 1 .61 P-3 Open N/A 900 .43 2 .55 494 .85 494 .81 0 .04 0 .00 0 .04 1.61 P-4 Open N/A 900 .43 2 .55 494 .81 494.44 0 .37 0 .00 0.37 1 .61 P-5 Open N/A 900.43 5 .75 494.44 491 .88 2 .56 0 .00 2 .56 11.62 P-6 Open N/A -599 .57 3 .83 491 .8 8 491 .92 0 .03 .0 .00 0 .03 5.47 P-7 Open N/A -599 .57 3 .83 49 1.92 492 .62 0 .71 0.00 0.71 5.47 P-8 Open N/A -599 .57 3 .83 492 .62 493 .03 0.41 0 .00 0.41 5.48 P-9 Open N/A -599 .57 3.83 493 .03 493.70 0 .67 0 .00 0 .67 5.47 P-10 Open N/A -599 .57 3 .83 493 .70 493 .99 0 .29 0 .00 0 .29 5 .48 P-11 Open N/A -599 .57 3 .83 493 .99 494 .14 0 .15 0 .00 0.15 5.48 P-12 Open N/A -599.57 3 .83 494 .14 494 .98 0 .84 0 .00 0 .84 5.47 P-13 Open N/A -599.57 0.43 494.98 495.00 0 .02 0 .00 0.02 0 .03 T ille: Brazos Va ll ey Bank -Phase 1 P roject Engineer: JOE SC H ULTZ c :ll1aestad \wtrc\br azos-bank-ph1 .wed TEXCON GENERAL CONTRACTORS WaterCAD v3 .1 [071 c) 03/2 4 /04 10 :24 :52 AM © H aestad Me1hods. In c. 3 7 Broo kside Road Waterbury . CT 06708 USA (20 3) 755-1666 P age 2 Brazos Valley Bank -Phase 1 Lavatory Water Closet Item Water Demand Analysis Quantity 3 3 Fixture Unit 1 2 .0 5.0 21 Fixture Units -Demand = 20.0 gpm 2 -5/8" Water Meter 1. Table E101 B -2000 International Plumbing Code 2. Table E102 -2000 International Plumbing Code Ex hibit "7'' Total Fixture Unit 6.0 15.0 21.0 Design Report Waterline Fire Flow Analysis for Brazos Valley Bank -Phase 1 College Station, Te·xas March 2004 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 690-7711 J ,_zs--o 1 ~ 3 .. 2te -b ~ \ ', 4-D ip YYl ~\R.--r3 1.0 INTRODUCTION & DESCRIPTION The purpose of this report is to provide a description of the existing waterlines located at the Graham Comer Plaza Subdivision, and to pro v id e the results of the analysi s of th e se waterline s under fire flow conditions. An existin g 24" waterline is loc ated along SH 6 frontage Road adjacent to the project site . Also , th ere is an existing 12 " waterl ine loc ated a long Graham Road and an existing 8" waterline through the subdivision alon g the ex istin g private driveway . The existing waterlines and fire hydrants will be used to meet the fire flow require m e nts for the Brazos Valley Bank -Phase 1 project. This project will consist of a temporary bank office building to be located on a portion of Lot 1 of the Graham Comer Plaza Subdivision. The office building will be a modular structure, 2 ,940 sf in size, that w ill b e placed on a concrete slab at the site and removed once the permanent office building is constructed with Phase 2 of the project. 2.0 FIRE FLOW REQUIREMENTS The flow required for fire hydrant flow for the commercial site is 2,500 gallons per minute (gpm), as required by the BCS Unified Design Guideline Manual. For this anal ysis , we have assumed that the flow comes from two hydrants. Due to the small size of th e proposed structure a separate analysis was performed using a fire flow of 1,500 gpm for Fire Hydrant No . 1. This is the fire hydrant closest to the proposed structure . The 2000 International Fire Code requires a minimum fire flow of 1,500 gpm for commercial buildings. 3.0 WATERLINE SYSTEM ANALYSIS The waterline system was analyzed using the WaterCAD computer program d eveloped b y Haestad Methods, Inc . Exhibit "l" is a schematic of the proposed waterlines , which shows the locations of the fire hydrants . The residual pressure in the existing 24 " waterline was determined by calculating the headloss at a flow of 2,500 gpm for the existing line. Exhibit "2" presents the results of a pressure/flow test from fire hydrants connected to the existing 12" waterline on Graham Road. A static pressure of 100 psi and a residual pressure of98 psi with the hydrant flow at 1,175 gpm were determined by Coll ege Sta tion Public Utility personnel. The residual pressure of 91.9 psi at a flow of 2 ,500 gpm was calculated usin g th e follo w in g equation : Wh ere: QR = Q ava ilabl e @ d esired res idu a l press ur e Qr = Q durin g fir e fl ow tes t HR = press ur e drop to d esired res idu a l pr ess ur e H1· =press ur e drop d urin g fir e fl ow tes t T hi s res u lts in a res id ua l pr ess ur e o f 9 i .9 ps i w he re the exi s t ing 12 " wa te rlin e co nnec ts to th e 24" wa te rlin e. T he hyd ra uli c g rad e was se t a t thi s pr ess ure a t thi s loc a ti o n. The computer model was run with a fire flow of 1,250 gpm at each of the existing fire hydrants for this project. The lowest residual pressure occurred in the system with this flow at fire hydrant No. 1 (Junction J-5) and fire hydrant No. 2 (Junction J-11). The pressure at this point is estimated by the model to be 90.9 psi, which exceeds the minimum of 20 psi required by the TCEQ regulations. The slight drop in pressure is due to the proximity of the fire hydrants to the 24" waterline , and also that the 8" waterline is "looped" between the 12" and 24" waterline . Exhibit "3" is a summary of the pipe system junction nodes for this scenario. Exhibit "4" is a summary of the pipe sections for the system under this demand scenario. The maximum velocity for the 8" water mains is 9 .0 feet per second, and occurs in Pipe P-12 . Minor losses were not considered in the analysis as they were not deemed to be significant. The computer model was also run with a fire flow of 1,500 gpm at Fire Hydrant No. 1. The lowest residual pressure is estimated by the model to be 91.4 psi, which exceeds the minimum of 20 psi required by the TCEQ regulations. Exhibit "5" is a summary of the pipe system junction nodes for this scenario . Exhibit "6" is a summary of the pipe sections for the system under this demand scenario . The maximum velocity for the 8" water mains is 5.8 feet per second, and occurs in Pipe P-5. The calculations for the; domestic water demand for this project are shown on Exhibit "7". A 5/8" water meter should be adequate for the demand of 20 gpm. This flow was not included in the Fire Flow Analysis because it is not significant. 4.0 CONCLUSIONS The waterlines proposed for this development should adequately provide the fire flow required with acceptable values for headloss and velocity. This analysis was done assuming adequate residual pressure in the existing 24" water main based on the flow test data presented in Exhibit "2". A separate analysis should be performed for the Phase 2 development and for any other development in this subdivision. 2 Scenario: Base R-1 P-1 J-1 P-2 -Flt~ J-2 J-3 P -4 J-4 P-5 Title: Brazos Va ll ey B ank -Phase 1 c:lh aes tadl wt rclbra z o s -bank-ph 1 . wed /PH Ff -5 P-6 J-6 P-7 P-8 J-8 P-9 J-9 TEXCON GENERAL CONTRACTORS P-1 3 J-1 0 P-1 0 03/24/04 0 1 :46:5 1 PM © H aestad M e th ods. Inc . 3 7 B rookside Road W aterbury. C T 06708 USA P -1 1 J-1 2 P -1 2 Project Enginee r : JOE SCHULTZ W a te rCAD v3 .1 !071cJ (203) 755-1 666 Page 1 or 1 , 03 1 01 /2004 1 3 :01 FAX 979 764 34 5 2 COL LE GE STATIO N PUB .UTL . 1601 GRAHAM ROAD COLLEGE STATION TEXAS 77845 Date: 27 FEB 04 Number pages including cover sheet -1 Fax to: 764-7759 Attention: JOE SCHULTZ Company: TEXCON From: Butch Willis Water Wastewater Division Phone: 979-764-3435 Fax: 979-764-3452 FLOW TEST REPORT Location: GRAHAM AT IDGHWA Y 6 FEEDER Flow hydrant number: Q-151 Pitot reading: 90 (GPM): 1175 Static hydrant number: Q-121 Static PSI: 100 Residual PSI: 98 @00 1 Node Elevation Demand Label (ft) T yp e J-1 283.00 demand J-2 2 83 .00 demand J-3 2 83.00 demand J-4 283 .00 demand J -5 280.50 demand J-6 280 .50 demand J-7 280 .00 demand J-8 280 .00 demand J-9 280.00 demand J-10 280 .00 demand J-11 280 .00 demand J-12 278.00 demand Title : Brazos Va ll ey Bank -Phase 1 c:ll1aestadlwtrclbrazos-bank-ph 1 . wed Demand (gpm) 0 .00 0 .00 0 .00 0 .00 1,250 .00 0 .00 0 .00 0 .00 0.00 0 .00 1 ,250.00 0 .00 03/24/04 10:18:30 AM © Ha es tad Me t11ods . In c . Scenario: Base Steady State Analysis Junction Report Demand Calculated Hydraulic Pressure Pattern Demand Grade (psi) (gpm) (ft) Fixed 0 .00 494 .84 91 .61 Fixed 0 .00 494 .79 91.58 Fi xed 0 .00 494 .73 91 .56 Fixed 0 .00 494 .21 91.33 Fixed 1 ,250.00 490 .59 90.85 Fixed 0 .00 490 .60 90.85 Fixed 0 .00 490 .66 91.10 Fi xed 0 .00 490 .70 91 .11 Fixed 0 .00 490 .76. 91 .14 Fixed 0 .00 490 .7 8 91 .15 Fixed 1 ,250.00 490 .80 91.16 Fixed 0 .00 494 .92 93 .80 TEXCO N GE NERAL CONT RAC TOR S 37 Brookside Road Wa te rbury. CT 06708 USA Proj ect Engineer : JOE SC HU LTZ Wa terCAD v3 .1 [07 1 c l (203) 755-1666 Analysis Results Scenario: Base Steady State Analysis Tille : Brazos Valley Bank -Phase 1 Project Enginee r: JOE SCHULTZ Project Date : 03/24/04 Comments : Scenario Summary Label Base Demand Alternative Base-Average Daily Physical Alternative Base-Physical Initial Settings Alternative Base-Initial Settings Operational Alternative Base-Operational Age Alternative Base-Age Alternative Constituent Alternative Base-Constituent Trace Alternative Base-Trace Alternative Fire Flow Alternative Base-Fire Flow Liquid Cha racte ristics Liquid Water at 20C(68F) Specific Gravity 1 .00 Kinematic Viscosity O .108e-4 ft'/s Network Inventory Number of Pipes 13 Number of Tanks 0 Number of Reservoirs 1 -Constant Area : 0 Number of Junctions 12 -Variable Area : 0 Number of Pumps 0 Number of Valves 0 -Constan t Power: 0 -FCV's : 0 -One Point (Design Point): 0 -PBV's : 0 -Standard (3 Point): 0 -PRV's: 0 -Standard Extended : 0 -PSV's: 0 -Custom Extended : 0 -TCVs: 0 -Multiple Point: 0 Number of Spot Elevations 0 Pipe Inventory Total Length Bin 12in 1,773 .00 ft 786 .00 ft 347 .00 ft 24in Pipes @ 0 .00 hr 640 .00 ft Label Sta tus Constituen t Flow Velocity From To Friction Minor Total Headless (ft/s) Grade Grade Loss LossHeadlosS3radient (mg/1) (gpm) (ft) (ft) (ft) (ft) (ft) (ft/1 OOOft) P-1 Open NIA 1,086 .21 3 .08 -95 .00 -94.84 0 .16 0 .00 0 .16 2.28 P-2 Open N/A 1,086.21 3 .08 -94 .84 -94 .79 0 .05 0 .00 0 .05 2 .28 P-3 Open N/A 1,086 .21 3.08 -94.79 -94 .73 0.05 0 .00 0 .05 2.28 P-4 Open N/A 1,086 .21 3.08 -94 .7 3 94.21 0 .52 0 .00 0 .52 2.28 P-5 Open NIA 1,086 .21 6 .93 -94 .21 -90 .59 3.62 0 .00 3.62 16.44 P-6 Open NIA -163.79 1.05 -90 .59 -90 .60 0 .3e-2 0 .00 0 .3e -2 0 .50 P-7 Open NIA -163 .79 1.05 -90 .60 -90.66 0 .06 0 .00 0 .06 0 .50 P-8 Open NI A -163.79 1.05 -90 .66 90 .70 0 .04 0 .00 0 .04 0 .50 P-9 Open NIA -163.79 1.05 90 .70 90 .76 0 .06 0 .00 0 .06 0.50 P-10 Open NI A -163 .79 1.05 -90 .76 90 .78 0 .03 0 .00 0 .03 0 .50 Tit le: Brazos Va ll ey Bank -Pha se 1 c:lha es ladlwtrclbrazos-bank-p h 1. wed TEXCO N GENE RAL CONTRACTORS 0312 4 104 10 :20 :4 0 AM © Haes tad Meth ods . Inc . 37 Brookside Road Waterbury. CT 06708 USA Ex_ k; ~ :J--' I 4 " Proj ect Engineer : JOE SC HULTZ Wa lerC AD v3 .1 (07 1c) (203) 755-1666 Page 1 of 2 I .-F z_ Pipes @ 0 .00 hr Analysis Results Scenario: Base Steady State Analysis Label StatusConstituent Flow V elo city From To Friction Minor Total Headl ess (mg/I) (gpm) P-1 1 Open NIA -163.79 P-12 Open NIA 1.413.79 P-13 Open NIA 1.413.79 Ti tl e: Brazos Va ll ey Bank -Phase 1 c:lhaestadl wtrcl brazos-bank-ph 1. wed (ft/s) G rade Grade Loss Loss H eadlosa;radi ent (ft ) (ft) (ft) (ft ) (ft) (ft/1 OOO ft ) 1 .05 -90 . 78 -90 .80 0 .01 0 .00 0 .01 0 .5 0 9 .02 -90 .80 -94 .92 4 .12 0.00 4 .12 26.77 1 .00 -94 .92 -95.00 0 .08 0 .00 0 .08 0 .13 TEXCON GENERAL CONTRACTORS 03124104 10:20:40 AM © Haes tad Me th ods , In c. 37 Brooks icle Road Wate rbury. CT 06708 USA &°..;h ; {,:cf--( '4> I I Project Engineer : JOE SC HULTZ W a te rCA D v3 .1 i071cJ (203) 755-1 666 Pag e 2 o f 2 Zof 2- Nod e Elevation Demand Label (ft) Type J-1 283 .0 0 demand J-2 2 83 .00 demand J-3 2 8 3 .0 0 d emand J-4 283 .00 demand J -5 280.5 0 demand J-6 280 .50 dema nd J -7 280 .00 d ema nd J-8 280 .00 d emand J-9 280 .00 demand J -10 280 .00 d emand J-11 280.00 demand J-12 278.00 demand Ti tl e : Brazos Va ll ey Bank -P llase 1 c:lllaestad\wtrc\brazos-bank-pll 1. wed Demand (gpm) 0 .00 0.00 0 .00 0 .00 1,500.00 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 0 .00 03/24/04 10 :25 : 1 3 AM © Haes lad M e tllods. Inc. Scenario: Base Steady State Analysis Junction Report Demand ~alculate d Hydraulic Pressure Pattern D emand G rade (psi ) (gpm ) (ft) Fixed 0 .00 494 .89 9 1 .63 Fi xed 0 .0 0 494 .8 5 91 .61 Fi x ed 0 .00 494 .81 9 1 .59 Fixed 0 .00 4 94.44 9 1 .43 Fixed 1 ,500.0 0 491 .88 9 1 .41 Fixed 0.00 491 .92 9 1 .42 Fi xed 0 .00 492 .62 9 1.95 Fi xed 0 .0 0 493 .03 92 .12 Fixed 0 .00 493.70 92.41 Fixed 0.00 493 .99 92 .54 Fixed 0 .00 4 94 .14 92 .60 Fi xed 0 .0 0 494.98 93 .8 3 " \\ s Proj ect Engi neer : JOE SC HULTZ TEXC ON GEN ERAL CONTRACTORS W a te rCAD v3.1 [071c) 37 Brookside Road Wa te rb ury. CT 06708 USA (203) 75 5-1666 Page 1 o f 1 Analysis Results Scenario: Base Steady State Analysis Pipes @ 0 .00 hr Label Status Con stituent Flow (mg/I) (gpm) P-1 Open N/A 9 00 .43 P-2 Open N/A 900.43 P-3 Open NIA 900.43 P-4 Open N/A 900 .43 P-5 Open N/A 9 00.43 P-6 Open N/A -599 .57 P-7 Open N/A -599.57 P-8 O pen NIA -599 .57 P-9 Open NIA -599.57 P-10 Open N/A -599.57 P-11 Open N/A -599.57 P-12 Open N/A -599.57 P-13 Open N/A -599.57 Ti tl e : Brazos Va ll ey Bank -Pllase 1 c:\11aes ladl wtrclbrazos-bank-pl11 .wcd Velocity (fVs) 2 .55 2 .55 2 .55 2 .55 5 .75 3 .83 3.83 3 .83 3.83 3 .83 3 .83 3.83 0.43 03124104 10 :2 4 :52 AM © Haes tad Mell1ods. Inc _ F rom To Friction Minor Total Head loss Grade Grade Loss Loss Headloss Gradient (ft) (ft) (ft) (ft) (ft) (ft/1 OOOft) 495.00 494 .89 0 .1 1 0 .00 0 .11 1 .61 494.89 494 .85 0 .04 0 .00 0 .04 1 .61 494.85 494.81 0 .04 0 .00 0 .04 1 .61 494.8 1 494 .44 0 .37 0.00 0 .37 1 .61 494.44 491 .88 2 .56 0 .0 0 2 .56 11 .62 491 .88 491 .92 0 .03 .0 .00 0 .03 5.47 491.92 492.62 0 .71 0 .0 0 0 .71 5.47 4 9 2 .62 493 .03 0 .41 0 .00 0.41 5.48 493.03 493 .70 0 .67 0 .00 0 .67 5.47 493 .70 493.99 0 .29 0 .00 0 .29 5.48 493 .99 494 .14 0 .15 0 .00 0 .15 5 .48 494.14 494 .98 0 .84 0 .00 0 .84 5.47 494.98 495.00 0 .02 0 .00 0 .02 0 .03 Project Engineer: JOE SC H ULTZ TEXCON GENERAL CONTRACTORS WaterCAD v3 . 1 [07 1cJ 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1 666 Paga 2 ' . Brazos Valley Bank -Phase 1 Lavatory Water Closet Item Water Demand Analysis Quantity 3 3 Fixture Unit 1 2 .0 5 .0 21 Fixture Units -Demand = 20.0 gpm 2 -5/8" Water Meter 1. Table E101B -2000 International Plumbing Code 2. Table E102 -2000 International Plumbing Code Ex hibit "7 " Total Fixture Unit 6.0 15.0 21.0 FOR OFFICE USE ONLY f '1 ·[)\)~ ().\-' \~ P&Z CASE NO .: 04 -1_5 DATE SUBMITTEDO 3-££-{;l) COLLUil STATION SITE PLAN APPLICATION q :35 fPf'11 yYl.fA.;1ricLJ ) MINIMUM SUBMITTAL REQUIREMENTS ../ Site plan application completed in full. -V $200 .00 Application Fee. ~ $200 .00 Development Permit Application Fee . N/A $600 .00 Public Infrastructure Inspection Fee if applicable . (This fee is payable if construction of a public waterline, sewerline , sidewalk, street or drainage facilities is involved .) ~Eleven (11) folded copies of site plan V One (1) folded copy of the landscape plan . ~One (1) copy of building elevation required for buildings with a footprint of 20,000 sq . ft . or greater ~A list of building materials for all facades that are visible from the public right-of-way . __L A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they are not checked off. l'J 1¢.. Parkland Dedication requirement approved by the Parks & Recreation Board ,. please provide proof of approval (if applicable). Date of Preapplication Conference: __ ~__._~_A __________________ _ NAME OF PROJECT 6ro.-za.S Vo-l\<"l & '1~ K -l-{..W\.pov-~..,..i D\A.-: ld ~ ..... J ADDRESS 'fl 0 Z... 5 ti ~ .$ o~t\.\ LEGAL DESCRIPTION Lo+\ 1 81oc..K l, ~rqh.OW"\ G:,rv-.~ PJ 1-'Z A APPLICANT/PROJECT MANAGER'S INFORMATION (Primary Con~ct for the Project): , Name ~~ h<r-\ ~ °''1 "e .. /\I A ,.. {2__. L. \J a'i (\( .ti As .foe ( '"-k s Street A~ss I 5" t> 9 ~-v-4--\J Oer-k vv~ 1 5"': ~ IO 4 City 4 1\., if; )t CJ..+; ...... State ( -c.st:A l Zip Code 11 fA-) E-Mail Address f P t)'1Y\~ c_. r ( (? o. 'inc:: . l'.-OWI Phone Number "14 .-foq /, -7 7... 17-Fax Number 9 7 C/-(p 'H~ ~ 8 If 4 PROPERTY OWNER'S INFORMATION : Name Bv-~vo~ \.)c>-\\~1 -}~k.. ""B""--:lJ~.,._J Grovf, L+J _ StreetAddress 2-S°b~ M~rr:V""-•L Lov-.rt City C.O.lJl~, f+C/+~··~ State Tc.µ ~ Zip Code I 7 2>4-~ E-Mail Address ±rvv G 1 o l 0\/. (~M Phone Number 9 1 °I -7 b 4 -1.. b ':J Fax Number 'I 7 °1 ' 0 ''1 -I J b 5 ARCHITECT OR ENGINEER'S INFORMATION : Name ~~-~~t~+~c~~~~~----=J-~~S~J-.-_:__~l~~--+-p_·~~--~~~~~~~~~~~ Street Address __ 1~7~~-1~-~_r_c._h_e~""'~-{Z~«>'--•,-'J~---­ State lC+" l Zip Code 11 ~{ S E-Mail Address Phone. Number "ll°J.-'7'24i--l1~3 6/13 /03 I u f 6 OTHER CONTACTS (Please spec ify type of contact , i.e. project manager, potential buyer, local contact , etc .) Name ----------------------------------- Street Ad dre ss ------------------City __________ _ State _____ Zip Code _____ _ E-Mail Address ____________ _ Phone Number ___________ _ Fax Number _____________ _ PRESENTUSEOFPROPERTY __ V_v_cc_~_t ___________________ ~ PROPOSED USE OF PROPERTY VARIANCE (S) REQUESTED AND REASON(S) __ N--+-/~A _______________ _ #OF PARKING SPACES REQUIRED _!_?..... __ #OF PARKING SPACES PROVIDED _1_5 __ MUL Tl-FAMILY RESIDENTIAL PARKLAND DEDICATION Total Acreage ____ _ #of Multi-Family Dwelling Units Floodplain Acreage ___ _ --x $452 = $ ------- Housing Units ____ _ _ __ #of acres in floodplain ___ # of 1 Bedroom Units _ __ # of acres in detention # of 2 Bedroom Units ---___ # of acres in greenways ___ # of 3 Bedroom Units ___ date dedication approved by Parks Board ___ # of 4 Bedroom Units COMMERCIAL FOR 2 BEDROOM UNITS ONLY Total Acreage _______ _ ___ #Bedrooms = 132 sq . ft . Building Square Feet _____ _ ___ #Bedrooms < 132 sq . ft . Floodpla in Acreage _____ _ NOTE : Parkland Dedication fee is due prior to the issuance of a Building Permit. The appli c ant has p re pa red this application and c ertifies that the fa c ts stated herein and exhibits a ttached hereto ar e and co rrec t. Date 61 13103 2 of 6 SUPPLEMENTAL DEVELOPMENT PERMIT INFORMATION Application is hereby made for the following development specific site/waterway alterations: / ~ < &-7...,. S \J ~ l \ B e "' " -T ~ w-. r:, r., r 0 {::.f; c: C. tS r.J cA ; ..._ ACKNOWLEDGMENTS: I , ~ t> S~ ~ \_. ~ -5 .._ h"" \+<.. , design e ngineer/owner, hereby acknowledge or affirm tha t: The information and conclus ions contained in the above pla ns and supporting documents comply with the current requirements of the City of College Stat ion , Texas City Code , Chapter 13 and its associated Drainage Policy and Design Standards. As a condition of approval of this perm it appl icat ion , I agree to construct the improvements proposed in th is application according to these documents and the requirements of Chap r 13 of the Colp,e at ion Ci Code . Property Owner(s) CERTIFICATIONS: (for proposed alterations within designated flood hazard areas .) A . I , e.. '-" ()_ 5 ....}...._, { + <.. certify that any nonresidential structure on or proposed to be on this site as part of this ap ication is designated to prevent damage to the structure or its contents as a result of flooding from the 1ooye"\\;;, ~ Q. W¢ -~3-' .6_r-_o_4-___ _ Engine~ U Date 8 . I, certify that the finished floor elevation of the lowest floor , including any basement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps , as amended. Engineer Date Conditions or comments as part of approval : ~~~~~~~~~~~~~~~~~~~~~~~~~~ In accordance with Chapte r 13 of the Code of Ordinan ce s of th e City of Colleg e Station , measures shall b e taken to i ns ure that debris from construction , erosion , and sedime n tation shall not be deposited i n city streets , or existing dra inage fac ilities . All development shall be in accordance with the plans and specifications submitted to and approved by the City Enginee r for the above named project. All of the appl icable co des and ord inances of the City of Co lle ge Station shall apply . 6/13 /03 3 of 6 Drainage Report for Brazos Valley Bank Phase 1 College Station, Texas March 2004 Developer: Brazos Valley Bank Building Group, Ltd. 2508 Merrimac Court College Station, Texas 77845 (979) 764-2667 Prepared fly_;_ TEXCON General Contractors 1707 Graham Road College Station, Texas 7 7 845 (979) 794-77 43 LE.GE STAno~; ENGINEERING nu:-\ 3-2(Q-ot{ o~-l~ \'-tl-0 f hi CERTIFICATION I, Joseph P. Schultz, Licensed Professional Engineer No. 65889, State of Texas , certify that this report for the drainage design for the Brazos Valley Bank, Phase 1 in College Station, Texas , was prepared by me in accordance with the provisions of the City of College Station Drainage Policy and Design Standards for the owners hereof, with the exception that storm water runoff detention is not being required for this project since the site discharges directly into an existing storm sewer system and then immediately into the 100-year floodplain limits . TABLE OF CONTENTS BRAZOS VALLEY BANK, PHASE 1 CERTIFICATION .................................................................................................................................................................. 1 TABLE OF CONTENTS ........................................................................................................................................................ 2 LIST OF TABLES .................................................................................................................................................................. 2 INTRODUCTION ................................................................................................................................................................... 3 GENERAL LOCATION AND DESCRIPTION .................................................................................................................. 3 FLOOD HAZARD INFORMATION .................................................................................................................................... 3 DEVELOPMENT DRAINAGE PATTERNS ....................................................................................................................... 3 DRAINAGE DESIGN CRITERIA .................................................... ~ ................................................................................... 3 STORM WATER RUNOFF DETERMINATION .............................................................................................................. .4 STORM SEWER PIPE & GRATE INLET DESIGN ......................................................................................................... .4 CONCLUSIONS ..................................................................................................................................................................... 5 APPENDIX A .......................................................................................................................................................................... 6 Calculations EXIITBIT A ............................................................................................................................................................................ 14 Post Development Drainage Area Map LIST OFT ABLES TABLE I -Rainfall Intensity & RunoffData .......................................................................................... 4 2 DRAINAGE REPORT BRAZOS VALLEY BANK, PHASE 1 INTRODUCTION The purpose of this report is to provide the hydrolo g ical effects of the construction of th e parking ar ea and temporary building for Phase 1 of th e Brazos Valley Bank, which is on Lot l , Block l of the Graham Comer Plaza project. This report will also show that the storm wate r runoff generated by this project will be collected b y a storm sewer system that ties into th e existing storm sewer system constructed with th e Graham Comer Plaza Subdi v ision proj ect. The existing storm system was designed for fully d eveloped conditions, so there should b e minimal offsite or downstream impact due to the construction of this project. GENERAL LOCATION AND DESCRIPTION The project is located on Lot 1, Block 1 of the Graham Comer Plaza developm ent (2.4 8 acres) located in College Station, Texas . The site is open land with grass. The existing ground e levations range from elevation 286 to elevation 2 89 . The general location of the project site is shown on the vicinity map in Exhibit A. FLOOD HAZARD INFORMATION The project site is located in the Lick Creek Drainage Basin. The site is located in a Zone X Area according to the Flood Insurance Rate Map (FIRM) prepared by the Federal Emergency Management Agency for Brazos County, Texas and incorporated areas dated February 9, 2000 , panel number 48041C0201 D. Zone X Areas are determined to be outside of the 500-yr floodplain. This site is not within the limit of study for the FIRM. However, the approximate 100-year floodplain limits and the floodway were previously determined by Robertson Engineering for the City of College Station, and these limits were included on the Final Plat for the project. None of the floodplain area is located on this site . DEVELOPMENT DRAINAGE PATTERNS The storm water runoff from this site is collected by the existing storm sewer system and then discharged into the North Fork of Lick Creek and the 100-year floodplain ; therefore , no detention is required for this project. The drainage area boundaries are shown on Exhib it A. DRAINAGE DESIGN CRITERIA The design parameters for the storm se wer are as follows : • The R ational Method is utili zed to determine peak storm w ater runoff rat es fo r th e s torm sewe r d es ign . • D es ign Storm Frequ ency Stom1 sewe r sys tem I 0 and 100-ye ar sto m1s eve nts • Runoff Coefficients Undeveloped areas Developed areas c = 0 .30 c = 0.85 • Rainfall Intensity equations and values for Brazos County can b e found in Table 1. • Time of Concentration, tc -Since these are smaller drainage areas , a minimum tc of l 0 minutes is used to determine the rainfall intensity values. STO RM WATER R UN O FF DETERMINATIO N The peak runoff values were determined in accordance with the criteria presented in th e previous section for the 10-, 25-and 100-year storm events. The runoff coeffici ents are based on the development of this tract. The drainage areas are shown in Exhibit A. Runoff conditions are summarized in Table 1. TABLE 1 -Rainfall I n tensity & Ru n off D a t a Area c 10 year sto rm 25 year storm 10 0 year storm tc Area# (acres) C1 C2 C 3 Crotar A1 Ai AJ T o t al ·201 2 .27 2 .27 0 .85 0 .8 5 1 0 .29 0 .29 0 .85 0.85 2 0 .23 0 .61 0 .84 0 .85 0 .3 0 .45 3 0 .24 0 .24 0 .85 0 .85 4 0.41 0.49 0 .90 0 .85 0 .3 0 .55 *207 1.07 1.07 0 .85 0 .8 5 • Refer to _,raham Corner Plaza Drainage Report for more information . T he Rationa l Method : Q =CIA Q =Flow (cfs) A= Are a (acres) C = Runoff Coeff. I = b I (ic+d)8 tc =Time of concentration (min) I = Rain fa ll Intensity (in/hr) Brazos County: 10 year storm b = 80 d = 8 .5 e = 0 .763 25 year storm b = 89 d = 8 .5 e = 0 .75 100 year storm b = 96 d = 8 .0 e = 0 .730 STO RM SEWER PIPE & GRATE INLET DESIGN (mi n ) 10 10 10 10 10 10 110 0 10 (i n/hr) (cfs) 8 .635 16 .66 8.635 2 .13 8 .635 3 .27 8.635 1 .76 8 .635 4 .28 8.635 7 .85 tc = U (V*60) L = Length (ft) l2s (in/h r) 9 .861 9 .861 9 .861 9 .861 9 .861 9 .861 V =Velocity (ft/sec) 0 2s 1100 (cfs) (in/hr) 19 .03 11 .639 2 .43 11.639 3 .73 11.639 2 .01 11 .639 4.89 11.639 8.97 11.639 This project consists of the construction of the parking area, storm sewer syste m and th e temporary building that is proposed for this site. The private storm sewer system w ill collect the runoff for this development , as well as the development of Phase 2. T he proposed storm sewer system w ill ti e into the ex isting pri vate storm sewer syste m a nd discharge it into th e North Fo rk of Li ck C reek . T he prop osed storm sewe r pip e sys tem is d esi gn ed fo r bo t h th e Ph ase l co ns tru c ti o n as we ll as th e futur e d eve lop ed conditi o n o f Lot 1, Block 1, w hi c h w ill o ccur w ith th e co nstru c ti o n o f Ph ase 2 at a late r tim e. G rat e inl ets w ill co ll ec t th e run off fr om th e Ph ase 1 de ve lopm e nt, a nd th e prop osed s to1111 sewer pip es w il l ti e int o th e ex is tin g Pi pe 2 (refe r to 4 0100 (cfs) 22.46 2 .87 4.41 2 .37 5 .77 10 .59 the Graham Comer Plaza Drainage Report, July 2003). Pipes 6 & 10 will b e constructed and the ends left open to collect the runoff from the Phase 2 area until the remainder of the storm sewer system is constructed with Phase 2. Silt fencing will be placed around the ends of the pipes to prevent sediment from entering the system. As previously stated , the storm water runoff from this site will be collected by the proposed storm sewer system, which ties into the existing storm system , which flows directly into the North Fork of Lick Creek. The storm sewer piping for this project has been selected to be Reinforced Concrete Pipe (RCP) meeting the requirements of ASTM C-76, Class III pipe meeting the requirements of ASTM C-789 for the 24" and 30" diameter pipes. The 15" and 18" pipe material will be A-2000 corrugated PV C pipe or HOPE pipe. The grate inlets in the pavement areas and the junction box will be cast -in- place or pre-cast concrete . The proposed storm sewer grate inlets were sized using the orifice equation, solvin g for the clear opening area : Q = 4.82 *Ag* y 112 ¢ Ag= QI (4.82 * y 112 ) where Q =capacity, cfs Ag = clear opening area, sq. ft. y = total depth of water on the inlet, ft. The capacities of the grate inlets were reduced by 50% for clogging. Data pertaining to inlet sizes and design calculations are summarized in Appendix A. The grate inlets were designed for a maximum depth of 6" for the 10-year storm event. There are no curb inlets proposed for this development. Appendix A contains a summary of the storm sewer pipe design parameters and calculations, including a summary of the flows through the storm sewer system for the l 0 and 100-year events. All pipes are 15" in diameter or larger. The pipes for the storm sewer system were designed based on the 10 -year storm event , and they will also pass the 100-year storm event. The velocity of flow in the storm sewer pipe system is not lower than 2.5 feet per second, and it does not exceed 15 feet per second. As the data shows , even during low flow conditions, the velocity in the pipes will exceed 2.5 feet per second and prevent sediment build-up in the pipes. The maximum flow in the storm sewer pipe system will occur in Pipe No. 5. The maximum velocity for the pipe system in this development will be 8.3 feet per second and will occur in Pipe No. 6 (once Phase 2 is constructed). Refer to Appendix A for calculations and data. CONCLUSIONS The construction of this project will increase the stom1 water runoff from thi s site. However, th e runoff will be collected by th e propos ed stom1 sewer syste m, connect to the exis tin g storm sewe r sys tem , a nd di sc harge into the I 00-year floodplain . The increased flow in this tributar y s ho uld not hav e a signi ft cant impact o n the surrounding property. No flood da ma ge to do w ns tr ea m or adj ace nt la ndo wners is ex pected as a res ult olt hi s deve lopmen t. APPENDIX A Calculations G Brazos Valley Bank Phase 1 Grate Inlet Summary Q = 4.82 *Ag * y 112 ¢ y = (QI (4 .82 * Ag))2 Where : Q = flow at inlet , cfs Inlet Number 3 4 Ag = open area of inlet, ft 2 y = depth at inlet , ft Inlet Model Grate Size number (in x in) V-5728 26 x 26 V-5728 26 x 26 Actual ~ in 2 370 .0 370 .0 Design A., 50% clogging in2 185 .0 185 .0 .-- 10-Year Storm 100-Year Storm Q10 Depth, y Q100 Depth, y (cfs) (ft) (in) (cfs) (ft) (in) 2.13 0.12 1.4 2 .87 0 .21 2 .6 ------ 1.76 0.08 1.0 2 .37 0 .15 1.8 ) Brazos Bank Phase 1 Pipe Calculations Pi pe# Size Len~th Slope (in) (ft) (%) 2 (Existin g) 30 167 .5 0 .70 5 30 51 .8 0 .70 ----- 6 24 87 .3 1.40 9 18 160 .8 1.10 -- 10 15 87 .5 0 .60 Pipe 2 0 10 Area 201 , 207 0 25 Area 201 , 207 0 100 Area 20 1, 207 Pipe 6 0 10 Area 207, 2 025 Area 207 , 2 0 100 A rea 207 , 2 · Pipe 10 0 10 Area 4 0 25 Area 4 0 100 Area 4 Inlet Outlet Invert Elev Invert Elev (ft) (ft) 277.45 276 .28 277 .96 277 .60 279 .68 278.46 280 .73 278.96 281 .50 280.98 = 24 .51 28 .00 = 33 .04 11.12 12.70 = 14 .99 4 .28 4 .89 5.77 10-year storm 100-year storm 010 V10 %Full Travel Time, t110 0 100 V 100 %Full Travel Time, t1100 (cfs) (fps) (sec) (min) (cfs ) (fps) (sec) (min) 24.51 7 .2 65 .8 23 0 .39 33 .04 7.4 85 .7 23 0.38 19 .29 6 .8 56 .1 8 0 .13 26 .00 7 .2 68.6 7 0 .12 11 .12 7 .7 46 .9 11 0 .19 14.99 8 .3 56 .0 11 0 .18 6.04 6 .0 55 .3 27 0 .45 8 .14 6.4 67.4 25 0.42 4 .28 4 .9 67 .0 18 0 .30 5.77 5.0 89 .7 18 0 .29 Pipe 5 010 Area 207, 1, 2, 3 , 4 = 19.29 0 25 Area 207 , 1, 2 , 3, 4 22.03 0100 Area 207 , 1, 2, 3, 4 26.00 Pipe 9 0 10 Area 3 , 4 6 .04 0 25 Area 3 , 4 = 6 .90 0 100 Area 3 , 4 8 .1 4 Pipe 2 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results : Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 30.0000 in 24 .5100 cfs 0 .0070 ft/ft 0 .0140 19.7309 in 4.9087 ft2 3.4234 ft2 56.7501 in 94 .2478 in 7 .1596 fps 8.6866 in 65.7698 % 31.8662 cfs 6.4917 fps Pipe 2 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter : ...................... . Flowrate ....................... . Slope .......................... . Manning's n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter .... · ................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Brazos Valley Bank, Phas e 1 College Station, Texas Circular Depth of Flow 30.0000 in 33.0400 cfs 0.0070 ft/ft 0.0140 25 .7185 in 4.9087 ft2 4.4792 ft2 71 . 0042 in 94 .2478 in 7 .3 763 fps 9.0841 in 85.7285 % 31.8662 cfs 6 .4917 fps Pipe 5 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................ · ·, · Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 30.0000 in 19 .2900 cfs 0.0070 ft/ft 0 . 0140 16.8414 in 4.9087 ft2 2.8370 ft2 50.8160 in 94.2478 in 6.7994 fps 8.0394 in 56.1379 % 31.8662 cfs 6 .4917 fps Pipe 5 -100 Year Storm Manning Pipe Calculator Given Input Data : Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ....................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Brazos Vall e y Ba n k, Phase 1 Col l e g e S t at io n , Tex a s Circular Depth of Flow 30 .0000 in 26.0000 cfs 0.0070 ft/ft 0. 0140 20.5949 in 4.9087 ft2 3.5924 ft2 58. 5910 in · 94.2478 in 7.2376 fps 8.8290 in 68 .6498 % 31.8662 cfs 6 .4917 fps Pipe 6 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diamete r ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ............................ . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 24 .0000 in 11.1200 cfs 0. 0140 ft/ft 0.01 4 0 11 .2490 in 3.1416 ft2 1. 4457 ft2 36 .1962 in 75 .3982 in 7 .6917 fps 5 .7515 in 46 .8709 % 24.8552 cfs 7.9117 fps Pipe 6 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow v elocity ............. . Brazos Vall ey Ba n k , Phase 1 Colleg e St atio n, Texas Circular Depth of Flow 24.0000 in 14 .9900 cfs 0 .0140 ft/ft 0 . 0140 13 .4418 in 3.1416 ft2 1 .8105 ft2 40.5897 in · 75.3982 in 8 .2794 fps 6 .4232 in 56.0074 % 24.855 2 cfs 7 .9117 fps Pipe 9 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning' s n .................... . Computed Results: Circular Depth of Flow 18.0000 in 6.0400 cfs 0 .0110 ft/ft 0 . 0140 Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 . 9491 in Area ............................ . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . 1.7671 ft2 1.0020 ft2 30.1760 in 56 .5487 in 6.0280 fps 4.7815 in 55.2726 % 10.2301 cfs 5.7891 fps Pipe 9 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Br azo s Valle y Ba n k , Phase 1 Coll ege St a t io n , Texas Circular Depth of Flow 18 .0000 in 8.1400 cfs 0.0110 ft/ft 0 . 0140 12 .1306 in 1 .7671 ft2 1 .2669 ft2 34.6692 in · 56. 5487 in 6 .4254 fps 5 .2619 in 67.3922 % 10.2301 cfs 5 .7891 fps Pipe 10 -10 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ............................ . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ...................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Circular Depth of Flow 15 .0000 in 4.2800 cfs 0.0060 ft/ft 0.0120 10.0523 in 1.2272 ft2 0 .8742 ft2 28.7705 in 47.1239 in 4.8957 fps 4 .3756 in 67.0151 % 5 .4207 cfs 4.4172 fps Pipe 10 -100 Year Storm Manning Pipe Calculator Given Input Data: Shape .......................... . Solving for .................... . Diameter ....................... . Flowrate ....................... . Slope .......................... . Manning ' s n .................... . Computed Results: Depth .......................... . Area ........................... . Wetted Area .................... . Wetted Perimeter ............... . Perimeter ....................... . Velocity ....................... . Hydraulic Radius ............... . Percent Full ................... . Full flow Flowrate ............. . Full flow velocity ............. . Brazos Valley Bank, Phas e 1 College Sta ti on , Texas Circular Depth of Flow 15.0000 in 5.7700 cfs 0.0060 ft/ft 0.0120 13. 4589 in 1. 2272 ft2 1.1607 ft2 37.3353 in 47.1239 in 4 .9710 fps 4.4769 in 89.7262 % 5.4207 cfs 4.4172 fps EXHIBIT A Post Development Drainage Area Map 14