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Home My WebLink AboutPM 12023 Phase 1 Bldg 18-20 Drainage Study C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX DRAINAGE CONCEPT REPORT McCutchen Commerce Center PM No. 12023, Lot 1 Phase 1, Bldgs. 18-20 Final Improvements Future Northeast Parking Bldg. 21 6900 McCutchen Road, Bakersfield CA September 14, 2017 Page 2 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX DRAINAGE CONCEPT – DISCUSSION: PRE – DEVELOPED (EXISTING) SITE CONDITIONS: The overall site (VTPM No. 12023 – Lots 1-4) currently comprises approximately 80 acres of vacant land which is currently being farmed. The land is relatively flat but does contain a gentle slope of about 3-4 feet vertical fall from the northerly edge of the site which is bordered by future Berkshire Road to the southerly edge of the site which is defined as McCutchen Road. The overall site is currently one lot but has received tentative approval for a parcel map. The approximate site overall dimensions are about 1300+ lineal feet east to west and about 2600+ feet north to south. The northerly 40+- acres is zoned R-2 and the southerly 40+- acres is zoned M-1. No deviance from the current zoning is planned at this point. Currently, approximately 9 acres of the south 40 acres have an active grading permit GP#15-400000-80 and are rough graded. The overall drainage report prepared by our firm dated March 17, 2016 has also been approved by the City of Bakersfield (Attachment 1) and is included for reference. The “north 40” acres which is zoned R-2 is, and will remain for the foreseeable future, vacant and utilized for agriculture purposes. This area is mapped on the tentative map as Parcels 2, 3 and 4. The topography of this area is gently sloping north to south however; only one to two feet of vertical relief exists within the approximately 1300 foot distance within these lots. In addition, an existing dirt raised road (about one foot high) exists near the southerly portion of Parcel 2. The area, currently in its agriculture use, is flood irrigated via a pump on the northwesterly quadrant of the site near future Berkshire Road and a pipe system that evenly distributes the irrigation water along the northerly edge of the property, and then the crops are flood irrigated via a gravity sheet flow that slowly distributes the irrigation water from north to south. The flows are then stopped and contained by the raised dirt road near the southerly lot line for Parcel 2. Therefore, no existing irrigation water or natural stormwater flows upon Parcels 2-4 are able to infiltrate into the area of Parcel 1 (the “south 40”). A similar situation occurs over Parcel 1 (the “south 40”). Natural or irrigated flows begin just immediately south of the raised dirt road and flow southerly to McCutchen Road where all flows are stopped and contained as the elevation of McCutchen Road is actually higher then Parcel 1. As a result, flows from the subject site are fully contained within the site and will remain so even in the ultimate fully improved proposed development. No flows from within the subject site do or will (in the future) flow to the offsite. In addition, flows from the adjacent properties to the north, east, and west also do not flow to within the subject property. For fairly obvious reasons, no pre-developed hydrology calculations were performed for this report. Page 3 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit A provides topographic information as shown on the tentative map. POST – DEVELOPED (PROPOSED) SITE CONDITIONS: The project relative to this drainage report is of only that portion of the southerly 40+- acre M-1 light industrial site described as Phase 1 and is located within the southeasterly portion of Parcel 1 of VTPM No. 12023. The area described is depicted on Exhibit B. The proposed improvements to the site include 3 new 20,469 square foot light industrial buildings (Building no. 18-20), landscaping and parking. Building 17 and its associated basins have already been approved and are in construction. Drainage from the public improvement is split into two areas and have been approved for drainage and are in construction as stated in the previously Approved Building 17 drainage study dated March 17, 2016. The hydrology calculations for all remaining drainage areas for Bldgs. 18-20 are provided in Exhibit C & C-1. The overall and ultimate light industrial project for Parcel 1 “south 40” is being designed as a commercial condominium and is so approved via the tentative conditions of approval. An association and relative CCR’s have been prepared, and the property association will manage and enforce all regulations as well as provide weekly maintenance to any and all drainage structures within the private onsite portion of this development. The project has been uniquely designed in that the site utilizes a series of shallow retention basins, with a maximum ponding depth of no more than 18 inches, within the front yard areas of each building rather than a typical singular deep and fenced retention basin in a corner of the development. A pictorial example of the ponding methodology can be seen via the rendering shown in Exhibit D and is applicable to the ponds fronting Building 18 thru 20 as previously approved for Building 17 as well as the ponds immediately across and on the east side of the roadway named Network Court. This methodology has been approved by the City of Bakersfield Public Works Department (See Approved Drainage Study Building 17 dated March 17, 2017). Since the private onsite driveways (roadways) have a flat centerline grade throughout the development, the roadway stormwater flows begin at the crown or centerline and thus drain to the roadway edge at 2% in a sheetflow (no concentration of drainage) condition or configuration. The edge of the roadways are not equipped with a standard curb and gutter but rather a concrete mow strip type edging that is flush with the edge of roadway surface, thus allowing the sheet flow drainage to exit the roadway and into the front yard retention basins. A cross sectional example of this can be seen in Exhibit G. The sloping between the roadway edge and bottom of basin will not exceed a gradient of 4 horizontal to 1 vertical. All of the shallow front yard retention basins within Phase 1 are connected Page 4 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX to each other via a series of 8” pvc type pipes or “Basin Interties” as they are referred to within the construction documents. Since the roadway centerlines are level, and the finish floor grades for all of the buildings are also level, the basins area also level at the bottom grade of the basin as well as the elevation of the design water surface (DWS) which is based upon the 100yr 24 hour rainfall event as required by the City of Bakersfield. It should be noted that, even though the basins are limited to a water depth of no more than 18”, the DWS for a 100 year storm is lower than the full possible 18” depth of the basin. As a result, the ponds can actually hold a much greater storm than what is required by city code. Also, what may initially appear to be separate basins in front of each building, they are indeed all connected with the basin intertie pipes and are thus one large connected basin as depicted in Exhibit C. This configuration provides a unique advantage in that, should one area provide a particularly greater infiltration or percolation rate than another, the ponding area of greater infiltration will actually help to ‘draw down” the other areas as stormwater will travel through the basin intertie pipes between one ponding area and another. Basin bottoms will be landscaped with low water consumption products as shown on the landscape plans. The major portion of the basin bottoms will be of a grassy type product called Kurapia. This product will provide the aesthetic appearance of a grass but requires vastly less water and only requires mowing periodically. In addition, since it is a living organism, it will provide a “bio-retention” type of system for cleaning source and non-source point pollutants from the stormwater prior to same entering into the percolation zones which ultimately end up recharging the groundwater aquifers. This type of natural bio-cleansing of pollutants is a much more effective method than the typical CDS or Vortechnix type units which are geared more towards eliminating trash and solids. A weekly gardener maintenance crew directed by the project association will provide regular pickup of trash and solids from all areas onsite. Other sources of stormwater inflow emanate from the roof and parking lot areas of the site. These are collected within catch basins and conveyed via 8” pvc pipes to an outlet into the bottom surface of the retention ponds near the bottom edge of the pond, which provides a bio-type filtration of the stormwaters which in turn will percolate into the groundwater aquifers. Again, since the bottom of the retention ponds are of a biological grassy type living and regenerating organism, there is, according to local city standards, no need to further provide any type of water quality products or remediation to the systems proposed. All hydrology calculations can be seen within Exhibit F. Calculations for the hydrology/hydraulics of onsite subareas for catch basins and pipes are also included within this report. As the methodology proposed within this project is allowable although somewhat unique, we have provided a system that utilizes a tremendous factor of safety within all of the calculations and the resultant product. Page 5 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX It should be noted for example as seen on Exhibit F, that the overall volume of retention within the basins within phase 1 is 192% of that which is required by the city. The conclusion can be drawn from Exhibit F and the above that the system proposed provides an extremely conservative and effective methodology for the project stormwater system, while providing numbers far in excess of that which is mandated by the city requirements. In addition, the aesthetic value of said system is more than evident as seen on Exhibit I. Once again, this stormwater retention/disposal system will be maintained weekly by the association to ensure functionality and appearance. It should also be noted that; in the event of a catastrophic rainfall event (far in excess of a 100 year storm) which may cause severe flooding; the finished floors of all buildings has been set to an elevation of at least one foot above the ultimate low flow site outlet which is located at the gutter flowline on McCutchen Road at the southeast corner of the project. Should this occur, flows would then travel offsite to the east in a natural condition as exists presently. As is evident on Exhibit F, the percolation rates and pond areas are vastly more than adequate to serve the purpose. It is hereby mandated within this report and the construction documents that the soils engineer be present onsite during construction to assure the materials being used at basin bottoms are compatible with the percolation rates required in order to assure compliance with city requirements. A supporting addendum soils report letter dated March 2, 2016 is included herein as Exhibit J. Hydrology and hydraulic calculations for onsite storm drain piping are also included herein and all supporting documentation for methodology relative to basin and pipe sizing is per standards by the City of Bakersfield, and those documents i.e. Plates D1 and D2 as well as excerpts from the city drainage standards section 2.3.2.1 along with section 2.8.2.1. In summary, we believe the proposed system not only serves the community better than normal deeper, fenced, and sometimes not well maintained aesthetically unpleasing standard retention basins, it also is in greater concert with the desires called for within the NPDES, CalGreen, and LID standards. In addition, since no “normal” storm drain and retention basin system is being proposed, there are no public catch basins or RCP piping or large “hole in the ground” (retention basins) areas, which in turn results in lowered developer costs, the elimination of city public funded maintenance costs over the years, and an additional building within the development which then results in additional tax revenues for decades or more for the city while also creating additional building square footage which will result in more jobs within the community. 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OFFlaAI_随COROS,龍飛持cOON丁子」とG王ND ①　剛ND㈹∪脚†寝るNO間 △　　S且青2“ BRASS cAP叩∞Nα涯1モiN曝しし調ARi優りしS 74き8 0o物12“ 。　善†洛譜隔晒硬肌C仲間灼 □　　　Sご丁2“脈〔職PiP己物巾I丁Acしま74き9 0罵.　僻照°∧」膝cOOS AC.　　AC京王S SF SOO雌「日E丁 (着し　　cROSS P.∪.エ.　PU閲C U¶uW EA剥各周丁服D H露遭O州 (R)　同的仙 / / / / W相l庵R OF l応報)qjしA照∧c∝SS則餅I了 ∂　　馴S¶N6 POⅥ駅戸の嘉績　　　悶S¶N6　音岬Å.「駅　VA」l∈ 〔し〔C口　　と灼S¶Nc田上c〇割c日0× -16“W鵜各XS¶青c肌瞭R UN且州D S)Z工 - SS　-岳鴫S¶Nc SANI了ARY :蓬脂uN巳㊤　　岳鴫S間c SANI丁ARY襲:W各R舶▲間帆と PH▲iiNG lll〔 LO†S SllOWN∴WAY BE; CONSTRUCltI) lN PH∧SCS. THE NUMB王R CF 離職AY NOT N関幾人尺-しY閲堪鋤碓00取説哩壁 T間S PRO,gcT ISしOCATED IN FEVA F|(×D INSURANCE fiATE uAP NO. EXHIBIT ’’A’’ Page 8 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit B Page 9 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit C & C-1 BUILDING 17 BUILDING 18 BUILDING 20 DRAINAGE AREA B TO POND 1 14,584 SF. C = 0.95 DRAINAGE AREA FUTURE 9 E'LY RG TO POND 1 19,859 SF. C = 0.50 DRAINAGE AREA FUTURE 16 E'LY RG TO POND 3 20,128 SF. C = 0.50 DRAINAGE AREA FUTURE 14 E'LY RG TO POND 7 19,994 SF. C = 0.50 DRAINAGE AREA FUTURE 13 E'LY RG TO POND 8 20,134 SF. C = 0.50 BUILDING 19 POND 1 POND 3 DRAINAGE AREA FUTURE 15 E'LY RG TO POND 5 32,062 SF. C = 0.50 POND 5 POND 7 POND 8 POND 10 DRAINAGE AREA FUTURE BLDG 21 S'LY RG TO POND 10 28,952 SF. C = 0.50 POND 9 DRAINAGE AREA BLDG 20 TO POND 9 59,137 SF. C = 0.80 DRAINAGE AREA BLDG 19 TO POND 6 69,374 SF. C = 0.80 POND 6POND 4 DRAINAGE AREA BLDG 18 TO POND 4 59,745 SF. C = 0.80 DRAINAGE AREA BLDG 17 WITH REAR SE & BLDG 18 TO POND 2 83,254 SF. C = 0.80 POND 2 DRAINAGE AREA A TO POND 2 15,104 SF. C = 0.95 Mc C U T C H E N R O A D NETWORK COURT PROJECT: MORAN DEVELOPMENT CORP. 7352 AUTOPARK DR. HUNTINGTON BEACH, CA 92648 CONTACT: JOE MORAN (714) 843-9116 C-HY-1 9/14/17DATE:HYDROLOGY STUDY EXHIBIT - C SHEET NO.: SCALE:HORIZ: NO SCALE VERT: NO SCALE LEGEND DRAINAGE AREAS PIPE 3 PIPE 1 PIPE 2 PIPE 5 PIPE 6 PIPE 4 PIPE 7 PIPE 9 PIPE 16 PIPE 12 PIPE 11 PIPE 13 PIPE 15 PIPE 14 PIPE 10 PIPE 8 PIPE 16PIPE 16PIPE 16 BUILDING 17 BUILDING 18 BUILDING 20 BUILDING 19 DRAINAGE SUB-AREA BUILDING 20 - ROOF AREA = 9,560 SF 0.22 ACRES DRAINAGE SUB-AREA BUILDING 17 - REAR SE & BUILDING 18 AREA = 26,450 SF 0.60 ACRES DRAINAGE SUB-AREA BUILDING 18 - REAR NE BUILDING 19 - REAR SE AREA = 26,300 SF 0.60 ACRES DRAINAGE SUB-AREA BUILDING 18 - NORTH PARKING AREA = 3,825 SF 0.09 ACRES DRAINAGE SUB-AREA BUILDING 19 - SOUTH PARKING AREA = 3,943 SF 0.09 ACRES DRAINAGE SUB-AREA BUILDING 19 - NORTH PARKING & HALF PIPE 7 AREA AREA = 3,775 SF 0.09 ACRES (16,904 TOTAL AREA) DRAINAGE SUB-AREA BUILDING 19 - REAR NE BUILDING 20 - REAR SE AREA = 26,259 SF 0.60 ACRES DRAINAGE SUB-AREA BUILDING 20 - REAR NE BUILDING 20 - NORTH PARKING TOTAL AREAS = 11,900 SF 0.27 ACRES DRAINAGE SUB-AREA BUILDING 19 - REAR NE BUILDING 120 - REAR SE AREA = 3,876 SF 0.09 ACRES (17,006 TOTAL AREA)DRAINAGE SUB-AREA BUILDING 20 - REAR NE AREA = 14,173 SF 0.33 ACRES DRAINAGE SUB-AREA BUILDING 20 - NORTH PARKING AREA = 814 SF 0.02 ACRES DRAINAGE SUB-AREA BUILDING 20 - NORTH PARKING AREA = 3,868 SF 0.09 ACRES DRAINAGE SUB-AREA FUTURE BLDG 21 - REAR NE AREA = 3,145 SF 0.07 ACRES DRAINAGE SUB-AREA BUILDING 20 - REAR NE BUILDING 20 - NORTH PARKING AREA = 353 SF 0.008 ACRES DRAINAGE SUB-AREA BUILDING 17 - ROOF AREA = 9,560 SF 0.22 ACRES DRAINAGE SUB-AREA BUILDING 18 - ROOF AREA = 9,560 SF 0.22 ACRES DRAINAGE SUB-AREA BUILDING 19 - ROOF AREA = 9,560 SF 0.22 ACRES PROJECT: MORAN DEVELOPMENT CORP. 7352 AUTOPARK DR. HUNTINGTON BEACH, CA 92648 CONTACT: JOE MORAN (714) 843-9116 C-HY-2 9/14/17DATE:PIPE ANALYSIS MAP EXHIBIT - C1 SHEET NO.: SCALE:HORIZ: NO SCALE VERT: NO SCALE LEGEND SUB-AREAS STORM DRAIN TIME OF CONCENTRATION Page 10 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit D EX H I B I T " D " Page 11 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit F Date: 8/28/2017 Lot Basin Design Calculation for Basin(s) Formula is:0.15 x C x Acres = Volume of Basin in Ac/ft Formula for basin capacity:V=1/6(Abtm+4Amid+Atop)D (18-inch Max. Stormwater Depth with 4:1 Side Slope Within DWS zone) Drainage Area (s.f.)C A (ac) V (ac/ft) Required Storage Abtm 4Amid Basin sq/ft @ top of 18" freeboard D to Total availa ble18" Depth Total Basin Ac.Ft. Volume to 18" Freeboard Total 18" Basin % Storage Provided vs. Req'd Fut 13-E'ly RG 20,134 0.50 0.462 0.034666 0.035 5693 26520 7,567 1.5 0.228 658.59% Fut 14-E'ly RG 19,994 0.50 0.459 0.0344249 0.034 3826 18380 5,364 1.5 0.158 459.64% Fut 15-E'ly RG 32,062 0.50 0.736 0.0552032 0.055 5770 28416 8,438 1.5 0.245 443.14% Fut 16-E'ly RG 20,128 0.50 0.462 0.0346556 0.035 5882 28936 8,586 1.5 0.249 718.80% Fut 9-E'ly RG 19,859 0.50 0.456 0.0341925 0.034 7946 36990 10,549 1.5 0.318 931.32% Area B-McCutchen 14,584 0.95 0.335 0.0477094 0.048 0 1.50 0.000 0.00% Bldg 17 83,254 0.80 1.911 0.2293499 0.229 3015 17116 5,543 1.5 0.147 64.25% Area A-McCutchen 15,104 0.95 0.347 0.0494105 0.049 0 1.50 0.000 0.00% Bldg 18 59,745 0.80 1.372 0.1645868 0.165 3552 20064 6,480 1.5 0.173 104.95% Bldg 19 69,374 0.80 1.593 0.1911129 0.191 3548 20066 6,485 1.5 0.173 90.39% Bldg 20 59,137 0.80 1.358 0.1629118 0.163 2553 14854 4,874 1.5 0.128 78.49% Fut 21-S'ly RG 28,952 0.50 0.665 0.0498485 0.050 6384 31952 9,592 1.5 0.275 551.81% 10.15 1.088 2.094 192% Conclusion: Surface Basins contain 192% of the capacity required per City of Bakersfield Standards for retention of 100 yr/24hr rain event. Perc Within Surface Retention Basins Phase 1a & 1b 1.088 ac.ft. storage needed = 47396 cu.ft. Note: Assumes a surface perc rate of 0.28 cu.ft/sq.ft/day for areas 1a and 1b (from soils report) Fut 13-E'ly RG 0.035 ac.ft. storage needed = 1510 cu.ft. 11158.3 cu.ft. in 7 days Sump Drains in 0.9 days Fut 14-E'ly RG 0.034 ac.ft. storage needed = 1500 cu.ft. 7499.0 cu.ft. in 7 days Sump Drains in 1.4 days Fut 15-E'ly RG 0.055 ac.ft. storage needed = 2405 cu.ft. 11309.2 cu.ft. in 7 days Sump Drains in 1.5 days Fut 16-E'ly RG 0.035 ac.ft. storage needed = 1510 cu.ft. 11528.7 cu.ft. in 7 days Sump Drains in 0.9 days Fut 9-E'ly RG 0.034 ac.ft. storage needed = 1489 cu.ft. and Area B-McC 15574.2 cu.ft. in 7 days Sump Drains in 0.7 days Bldg 17 0.229 ac.ft. storage needed = 9990 cu.ft. and Area A-McC 5909.4 cu.ft. in 7 days Sump Drains in 11.8 days Bldg 18 0.165 ac.ft. storage needed = 7169 cu.ft. 6961.92 cu.ft. in 7 days Sump Drains in 7.2 days Bldg 19 0.191 ac.ft. storage needed = 8325 cu.ft. 6954.1 cu.ft. in 7 days Sump Drains in 8.4 days Bldg 20 0.163 ac.ft. storage needed = 7096 cu.ft. 5003.9 cu.ft. in 7 days Sump Drains in 9.9 days Fut 21-S'ly RG 0.050 ac.ft. storage needed = 2171 cu.ft. 12512.6 cu.ft. in 7 days Sump Drains in 1.2 days 81898.6 cu.ft. in 7 days = 4.05 days Note: Perc Rates and relative calculations taken from soils report by Salem Engineering Company. Surface sumps will drain in average of Total Surface Perc in Basins = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = direct perc in sump = McCUTCHEN COMMERCE CENTER 6900 McCutchen Road - Bakersfield, Ca On-Site Sumps including Public Streets & Private Driveway Drainage using 34'-wide Driveways and no interior Curb & Gutter ENTIRE Lot Drainage-includes Streets/Driveways For Buildings 17 - 20, and 660' of McCutchen Road north side Adequate Soils Substituted at Surface for Perc @ 2.1 gal/sf/day 100yr Storage/Sump HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 1-3 - Bldg 17 Rear Building & Bldg 18 SE Corner Inflow Area Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 195 feet Average slope = 0.91%0.009 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 224.00 Feet RipRap=0.030, Grassland=0.035 Velocity 5.5 fps Travel Time = 0.6 minutes Add overland flow 6.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.6 minutes (travel) + 6.0 minutes overland =16.6 Tc = 16.6 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.75 from C.O.B.Development Standards-Plate D-1 a =0.60721 from hydrology plan Calculate Q10 =0.96 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 223 L.F. of 8 " PVC Pipe 1, 2 and 3 invert elevation in-351.12 Q10 =0.96 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.005 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.070866 Q= (capacity) 1.03 cfs =93% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.070866 Velocity= 2.9 fps Conclusion:8 " Pipe @ 0.50 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 4 Inflow Area Bldg 18 NE Rear Corner & Bldg 19 SE Corner Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 196 feet Average slope = 0.90%0.009 ft/ft n factor 0.015 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 56.50 Feet RipRap=0.030, Grassland=0.035 Velocity 5.8 fps Travel Time = 0.6 minutes Add overland flow 6.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.6 minutes (travel) + 6.0 minutes overland =16.6 Tc = 16.6 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.75 from C.O.B.Development Standards-Plate D-1 a =0.60608 from hydrology plan Calculate Q10 =0.95 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 56.5 L.F. of 8 " PVC Pipe 4 invert elevation in-351.12 Q10 =0.95 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.005 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.070334 Q= (capacity) 1.02 cfs =94% full invert elevation out-----350.84 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.070334 Velocity= 2.9 fps Conclusion:8 " Pipe @ 0.49 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No.5 Inflow Area Bldg 18 North Parking Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 351.00 Distance between high and low points = 69 feet Average slope = 4.91%0.049 ft/ft n factor 0.015 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 150.50 Feet RipRap=0.030, Grassland=0.035 Velocity 13.6 fps Travel Time = 0.1 minutes Add overland flow 6.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.1 minutes (travel) + 6.0 minutes overland =16.1 Tc = 16.1 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.75 from C.O.B.Development Standards-Plate D-1 a =0.68781 from hydrology plan Includes Sum Area Bldg 18 NE Rear 0.30 acres Calculate Q10 =1.08 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 150.5 L.F. of 8 " PVC Pipe 5 invert elevation in-350.84 Q10 =1.08 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.006 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.074833 Q= (capacity) 1.08 cfs =100% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.074833 Velocity= 3.1 fps Conclusion:8 " Pipe @ 0.56 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No.6 Inflow Area Bldg 19 South Parking Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 351.00 Distance between high and low points = 86 feet Average slope = 3.94%0.039 ft/ft n factor 0.015 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 145.00 Feet RipRap=0.030, Grassland=0.035 Velocity 12.1 fps Travel Time = 0.1 minutes Add overland flow 6.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.1 minutes (travel) + 6.0 minutes overland =16.1 Tc = 16.1 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.75 from C.O.B.Development Standards-Plate D-1 a =0.48051 from hydrology plan Includes Sum Area Bldg 18 NE Rear 0.30 acres Calculate Q10 =0.76 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 145 L.F. of 8 " PVC Pipe 6 invert elevation in-350.84 Q10 =0.76 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.006 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.076092 Q= (capacity) 1.10 cfs =69% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.076092 Velocity= 3.1 fps Conclusion:8 " Pipe @ 0.58 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 7&7A Inflow Area BLD 19 NE REAR & BLDG 20 SE REAR Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 113 feet Average slope = 1.57%0.016 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 56.50 Feet RipRap=0.030, Grassland=0.035 Velocity 7.2 fps Travel Time = 0.3 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.3 minutes (travel) + 0.0 minutes overland =10.3 Tc = 10.3 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.60282 from hydrology plan Calculate Q10 =0.98 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 56.5 L.F. of 8 " PVC Pipe 7 invert elevation in-351.12 Q10 =0.98 Props'd Pipe(feet)0.67 Proposed Slope 0.005 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.070711 Q= (capacity) 1.02 cfs =95% full invert elevation out-----350.84 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.070711 Velocity= 2.9 fps Conclusion:8 " Pipe @ 0.50 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 8 Inflow Area BLDG 19 NORTH PARKING Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 88 feet Average slope = 2.01%0.020 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 150.00 Feet RipRap=0.030, Grassland=0.035 Velocity 8.1 fps Travel Time = 0.2 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.2 minutes (travel) + 0.0 minutes overland =10.2 Tc = 10.2 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.38806 from hydrology plan Calculate Q10 =0.63 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 150 L.F. of 8 " PVC Pipe 8 (includes inflow from pipe 7) invert elevation in-350.84 Q10 =0.63 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.006 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.074833 Q= (capacity) 1.08 cfs =58% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.074833 Velocity= 3.1 fps Conclusion:8 " Pipe @ 0.56 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 INCLUDES HALF BLDG 19 NE REAR & BLDG 20 SE REAR HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 9 Inflow Area BLDG 20 SOUTH PARKING Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 87 feet Average slope = 2.03%0.020 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 150.00 Feet RipRap=0.030, Grassland=0.035 Velocity 8.2 fps Travel Time = 0.2 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.2 minutes (travel) + 0.0 minutes overland =10.2 Tc = 10.2 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.3904 from hydrology plan Calculate Q10 =0.63 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 148 L.F. of 8 " PVC Pipe 8 (includes inflow from pipe 7) invert elevation in-350.84 Q10 =0.63 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.006 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.075498 Q= (capacity) 1.09 cfs =58% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.075498 Velocity= 3.1 fps Conclusion:8 " Pipe @ 0.57 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 PLUS HALF BLDG 19 NE REAR & BLDG 20 SE REAR HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 10-12 Inflow Area Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 354.39 Elevation @ gutter or flowline/invert lowpoint = 353.18 Distance between high and low points = 170 feet Average slope = 0.71%0.007 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 0.00 Feet RipRap=0.030, Grassland=0.035 Velocity 4.8 fps Travel Time = 0.6 minutes Add overland flow 6.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.6 minutes (travel) + 6.0 minutes overland =16.6 Tc = 16.6 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.75 from C.O.B.Development Standards-Plate D-1 a =0.32537 from hydrology plan Calculate Q10 =0.51 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 195 L.F. of 8 " PVC Pipe 10, 11, and 12 invert elevation in-350.68 Q10 =0.51 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.003 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.058992 Q= (capacity) 0.85 cfs =60% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.058992 Velocity= 2.4 fps Conclusion:8 " Pipe @ 0.35 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 13 BLDG 20 NORTH PARKING Inflow Area Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 353.94 Elevation @ gutter or flowline/invert lowpoint = 353.23 Distance between high and low points = 78 feet Average slope = 0.91%0.009 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 0.00 Feet RipRap=0.030, Grassland=0.035 Velocity 5.5 fps Travel Time = 0.2 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.2 minutes (travel) + 0.0 minutes overland =10.2 Tc = 10.2 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.0888 from hydrology plan Calculate Q10 =0.14 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 14 L.F. of 8 " PVC Pipe 13 invert elevation in-350.53 Q10 =0.14 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.038 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.194422 Q= (capacity) 2.81 cfs =5% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.194422 Velocity= 8.0 fps Conclusion:8 " Pipe @ 3.78 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 14 FUT.BLDG 21 NE REAR PARKING Inflow Area Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 353.94 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 69 feet Average slope = 1.91%0.019 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 0.00 Feet RipRap=0.030, Grassland=0.035 Velocity 7.9 fps Travel Time = 0.1 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.1 minutes (travel) + 0.0 minutes overland =10.1 Tc = 10.1 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.0722 from hydrology plan Calculate Q10 =0.12 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 32.5 L.F. of 8 " PVC Pipe 14 invert elevation in-350.41 Q10 =0.12 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.002 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.044721 Q= (capacity) 0.65 cfs =18% full invert elevation out-----350.35 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.044721 Velocity= 1.8 fps Conclusion:8 " Pipe @ 0.20 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.Pipe No. 15 FUT BLDG 21 NE PARKING Inflow Area Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 353.85 Elevation @ gutter or flowline/invert lowpoint = 352.62 Distance between high and low points = 60 feet Average slope = 2.05%0.021 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 0.00 Feet RipRap=0.030, Grassland=0.035 Velocity 8.2 fps Travel Time = 0.1 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.1 minutes (travel) + 0.0 minutes overland =10.1 Tc = 10.1 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.0803 from hydrology plan PLUS SUM AREAS PIPE 14&15 Calculate Q10 =0.13 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 64 L.F. of 8 " PVC Pipe 15 invert elevation in-350.35 Q10 =0.13 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.005 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.073946 Q= (capacity) 1.07 cfs =12% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.073946 Velocity= 3.0 fps Conclusion:8 " Pipe @ 0.55 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 HYDROLOGY/HYDRAULIC CALCULATIONS Project Address: McCutchen Commerce Center JBC 1002.1Date: 9/9/2017 AREA NO.PIPES 16-19 BLD 17-20 ROOF TO BASINS Given: Site Designation:Light Industrial M-1 Develop Time of Concentration:Type of Flow = Open Channel - Paved Tc base time (roof to gutter) 10 Elevation @ gutter or flowline/invert highpoint = 370.39 Elevation @ gutter or flowline/invert lowpoint = 352.20 Distance between high and low points = 109 feet Average slope = ######0.167 ft/ft n factor 0.016 Concrete=0.013, AC Parking=0.016, AC Roads=0.018, Proposed Pipe(feet) 0.00 Feet RipRap=0.030, Grassland=0.035 Velocity 23.4 fps Travel Time = 0.1 minutes Add overland flow 0.0 minutes (from C.O.B.Development Standards-2.3.2.1) Tc = 10 minutes (base)+0.1 minutes (travel) + 0.0 minutes overland =10.1 Tc = 10.1 minutes Develop Hydrology: Q = cia Q=design runoff in cfs, c=runoff coefficient, i=intensity in inches/hr, a=area in acres Given: Storm Frequency:10 year - Local Waterway c =0.9 from C.O.B.Development Standards-Plate D-2 i =1.80 from C.O.B.Development Standards-Plate D-1 a =0.21947 from hydrology plan PLUS SUM AREAS PIPE 14&15 Calculate Q10 =0.36 cfs Develop Hydraulic Calculations For Closed Conduit Pipe: Pipe Analysis for 12 L.F. of 8 " PVC Pipe 15 invert elevation in-352.22 Q10 =0.36 cfs Props'd Pipe(feet)0.67 Proposed Slope 0.185 n factor 0.011 (SDR 35 or equal) Q = A(1.486/n)(R2/3*S1/2) A= 0.352566 1.486/n= 135.0909 R2/3= 0.303862 S1/2= 0.430116 Q= (capacity) 6.22 cfs =6% full invert elevation out-----350.00 Velocity V = (1.486*R2/3*S1/2)/n constant 1.486 R2/3= 0.303862 S1/2= 0.430116 Velocity= 17.7 fps Conclusion:8 " Pipe @ 18.50 % OK minutes (from C.O.B.Development Standards-2.3.2.1), Natural Open = 0, R3/Commercial/Industrial = 10, R1/R2 = 15 Page 12 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit G NOTES:1. OVEREXCAVATE TO A DEPTH OF 11 F E E T B E L O W E X I S T I N G G R A D E A N D B A C K F I L L T O E L E V A T I O N 350.00 WITH A MATERIAL APPROVE D B Y T H E S O I L S E N G I N E E R T O E N S U R E A D E Q U A T E P E R M E A B I L I T Y FOR WATER TO DRAIN IN SEVEN DA Y S O R L E S S . A S O I L S E N G I N E E R I S R E Q U I R E D T O B E O N S I T E D U R I N G CONSTRUCTION OF THE SUMP.2. PONDING BASINS NOT TO EXCEED 1 8 " A T M A X I M U M D E P T H T O O V E R F L O W / O U T L E T . 3. UPON COMPLETION OF THE CONST R U C T I O N O F T H E B A S I N , T H E S O I L S E N G I N E E R S H A L L P R O V I D E T H E CITY WITH WRITTEN VERIFICATION TH A T T H E R E Q U I R E M E N T S H A V E B E E N M E T P E R D R A I N A G E APPROVAL LETTER.4. THE RETENTION BASINS, ONSITE CAT C H B A S I N S A N D S T O R M D R A I N S Y S T E M S H A L L B E M A I N T A I N E D PRIVATELY AND THE CITY OF BAKERS F I E L D W I L L N O T A S S U M E R E S P O N S I B I L I T Y O V E R T H E MAINTENANCE. N E T W O R K C O U R T 5 ' SIDESLOPES TO DAYLITE AT 5:1 MAX.POND SIDESLOPES AT 4:1 MAXADDITIONALSTORAGE-EXCEEDS REQUIRED100 YEAR REQUIREDSTORAGE MAX. OUTLET/OVERFLOW AT 351.50100 YEAR DWSAT 350.82 VARIES PROP 6" WIDE x 1' DEEPCONC. MOW STRIP (TYP.) P R O P 8 " P V C B A S I N I N T E R T I E , L E V E L @ I N V E R T 3 5 0 . 0 0 BTM=350.00 F F = 3 5 4 . 3 9 3 5 3 . 2 8 F S H P P R O P . F S O V E R S T O R M D R A I N 3 5 2 . 6 2 T G 3 5 3 . 0 6 F L H P 3 5 2 . 6 2 T G P R O P . 8 " P V C P R O P . C A T C H B A S I N P R O P . C A T C H B A S I N P R O P . 8 " P V C B T M = 3 5 0 . 0 0 P R O P . 3 4 ' W I D E P R I V A T E D W Y 3 5 1 . 8 4 F S C L 2 % 2 % 1 7 ' 1 7 ' M I N I M U M 2 % S L O P E A W A Y F R O M B U I L D I N G I N F I R S T 5 F E E T . A P P L I E S T O A L L S I D E S O F B U I L D I N G . ( T Y P . ) 3 5 0 . 4 8 H G L 3 5 0 . 0 0 I N V . @ O U T L E T S E E N O T E 1 A D D I T I O N A L S T O R A G E - E X C E E D S R E Q U I R E D 1 0 0 Y E A R R E Q U I R E D S T O R A G E P O N D S I D E S L O P E S A T 4 : 1 M A X M A X . O U T L E T / O V E R F L O W A T 3 5 1 . 5 0 1 0 0 Y E A R D W S A T 3 5 0 . 8 2 P R O P . S I D E W A L K SEE NOTE 1 VARIES 3 5 0 . 0 0 P O N D E D G E 3 5 0 . 0 0 P O N D E D G E B U I L D I N G 1 8 - 2 0 EXHIBIT G Page 13 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit I EX H I B I T " I " Page 14 C:\USERS\GMEND\DESKTOP\1002_1 PHASE 1 BLDG 18-20 DRAINAGE REPORT_9-14_17.DOCX Exhibit J 4729 W. Jacquelyn Avenue Fresno, CA 93722 Phone (559) 271-9700 Fax (559) 275-0827 SAN JOSE ▪ STOCKTON ▪ FRESNO ▪ BAKERSFIELD ▪ RANCHO CUCAMONGA March 2, 2016 Project No. 2-212-0480 Mr. Jack Brey JB Consulting Services, LLC 9519 Lake Superior Drive Bakersfield, CA 93312 Subject: DESIGN MEMORANDUM- STORMWATER RETENTION BASINS PROPOSED MCCUTCHEON & RELIANCE COMMERCIAL DEVELOPMENT NEC MCCUTCHEON ROAD & RELIANCE DRIVE BAKERSFIELD, CALIFORNIA Dear Mr. Brey: SALEM Engineering Group, Inc. (SALEM) is pleased to submit this Stormwater Retention Basin Design Memorandum for the subject site located in Bakersfield, California. JB Consulting Services, LLC (JB) authorized the scope of work in a March 1, 2016 communication. 1.0 PROJECT DESCRIPTION SALEM previously conducted a Geotechnical Engineering Investigation Update for the above-noted project summarized in our report dated November 18, 2015. On a preliminary basis, it is understood that development will include the construction of 24 condominium type commercial structures. The structures range in size from approximately 9,000 sq. ft. to approximately 18,000 sq. ft. and are anticipated to be single or two story masonry structures utilizing conventional footings and slab-on-grade construction. Distributed landscape areas will be designed to accept storm water run-off in lieu of the centralized storm water retention area originally planned. SALEM previously conducted several percolation tests at the project site. Testing data suggested the proposed infiltration basins (as originally designed) would not meet the 7-day drain time requirement. As such, our 2015 Geotechnical Engineering Investigation Update report proposed construction of infiltration sumps (trenches) within the retention basin floor. The current drainage system design includes construction of two to three approximately 40 foot long by 10 foot wide by 11 foot deep rock-filled trenches at the center of the retention basins to allow rapid infiltration through a surficial, lower-permeability soil horizon into more permeable underlying sediments. 2.0 ALTERNATE BASIN DESIGN RECOMMENDATIONS Pertinent conclusions from our previous geotechnical investigations at the subject site include:  Geotechnical soil boring logs from throughout the proposed development show that a moderately permeable silty sand exists at depths of 3 to 5 feet below a lower-permeability sandy silt surface soil. Project No. 2-212-0480 Page 2 of 3  During 2012, SALEM conducted eight shallow percolation tests throughout the site. The tests were conducted in both the sandy silt and underlying silty sand soil horizons. Testing results suggest the silty sand unit is capable of absorption rates of at least 2 gal/ft2/day — a rate sufficient to allow the planned basins to drain within 7 days.  SALEM recommended soil overexcavation of at least 12 inches below building footings that are at least 18 inches below lowest adjacent grade. SALEM is aware that a City of Bakersfield-approved mitigation method for slow infiltration rates in stormwater basins includes the removal and replacement of lower permeability materials at the design basin floor with materials with sufficient permeability to meet the 7-day drain time requirement. As an alternative to the design recommendations in our 2015 report, SALEM recommends the following:  While conducting grading operations for the site building pads, continue overexcavation into the lower silty sand unit and stockpile these soils. Excavate and stockpile sandy silt surficial soil from the bottoms of proposed basins to a depth that penetrates into the lower silty sand unit.  Place and compact the lower permeability soils into the building pad excavation and bring to planned grade. Place and compact the higher-permeability silty sand soil over the basin floor area. The basin floor replacement soils should be placed in lifts, moisture conditioned to near optimum moisture content, and compacted to between 90% to 92% relative compaction.  SALEM personnel should conduct adequate testing and observations during building pad excavation and replacement of the basin floors to ensure that material properties meet the intent of this alternative design recommendation.  Following completion of basin floor replacement, one percolation test for each 4 to 5 basins should be conducted to verify the alternative design absorption rates. 3.0 LIMITATIONS The analyses and recommendations submitted in this memorandum are based upon the data obtained from previous test borings and percolation tests conducted by SALEM, and from data obtained from JB. The memorandum does not reflect variations which may occur between test locations. The nature and extent of such variations may not become evident until construction is initiated. The findings and recommendations presented in this memorandum are valid as of the present and for the proposed construction. If site conditions change due to natural processes or human intervention on the property or adjacent to the site, or changes occur in the nature or design of the project, or if there is a substantial time lapse between the submission of this report and the start of the work at the site, the conclusions and recommendations contained in our report will not be considered valid unless the changes are reviewed by SALEM and the conclusions of our report are modified or verified in writing. The validity of the recommendations contained in this memorandum is also dependent upon an adequate testing and observations program during the construction phase. Our firm assumes no responsibility for construction compliance with the design concepts or recommendations unless we have been retained to perform the on- site testing and review during construction. SALEM has prepared this memorandum for the exclusive use of the owner and project design consultants. Project No. 2-212-0480 Page 3 of 3 We appreciate the opportunity to submit this Design Memorandum. Should you have questions regarding this proposal, please contact the undersigned at (559) 271-9700. Respectfully submitted, SALEM Engineering Group, Inc. Bruce E. Myers, PE, CEG Senior Engineer / Eng. Geologist PE 62067 / CEG 2102