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HomeMy WebLinkAboutSite Certifications - 09/20/1994IL it STEWART&ASSOCIATES Consulting Engineers and Surveyors September 19, 1994 Mr. Basil Hamdan Storm Water Utility City of Fort Collins P.O. Box 580 Fort Collins, CO 80522 Dear Basil: final AI rr ��? Pon D a t!' f7, C. o. re: Schrader County Store on Lot 1 of Horsetooth Commons P.U.D. The landscaping of the site is now completed with the installation of sod, so all permanent erosion control is now in place. Sincerely, c+ Phillip I. Robinson Vice President4502 ,t /rsc James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522, 303/482-9331 Fax 303/482-9382 a 31 STEWART&kSSOCIATES Consulting Engineers and Surveyors August 19, 1994 Mr. Glen Schlueter Storm Water Utility City of Fort Collins P.O. Box 580 Fort Collins, Colorado 80522 Dear Glen: I have surveyed the as —built drainage facilities at the Schrader Country Store on Lot 1 of Horsetooth Commons P.U.D. located at the northwest corner of Horsetooth Road and Shields Street. The as —built grades of the drain swale on the north side of the building, the floor elevations, the area inlet and detention pond area, and the berms are accurately shown in redline on the attached drainage and erosion control plan. This plan was prepared by Advanced Professional Engineers, Inc. The required 4—inch orfice plate is installed over the outlet pipe in the area inlet. The area inlet grate;.was lowered 0.4 feet to provide positive drainage along the east curb and drain pan to the grate '. - I have calculated the volume of the detention pond to be 4767 cubic feet, which is slightly more than the required volume of 4752 cubic feet per the APEI report. I inspected the site on August 18, 1994, and at that time the grading was completed and the site was ready for landscaping and sodding. I am attaching a copy of the APEI amended report along with a copy of my calculations of the pond volume. Please call if you have any questions. Sincerely, Phillip I. Robinson, P.E. & L.S. Vice. President jrr enclosures James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522 303/482-9331 Fax 303/482-9382 STEWART&ASSOCIATES 103 S. MELDRUM, FORT COLLINS, CO 80521, Consulting Engineers and Surveyors PH. 482-9331 FAX 482-9382 By: Date: Client: br-Qbo-6t c-ow4% Sheet No. -Lof-L c- Project: 5� r,, de r- Cuukili v 1�cr-,- /U%t/ cor 14of-ye-4vrA 4 sAirte't Subject: De_4e_4f0h 'pokc-i L101CIIIVe w4te c t e Vt 4_1 010 r- -T. .. . ..... A I=ESSIUNAL ENGINE INC. JADVANCED PRO 0 REGISTERIsU PIiOPESSIONAI„ CONSULTANT ENGINEIER.S ANU LAND SURVE'V011S P.O. BOX 1391, FORT COLLINS, COLORADO 80522-1,391 USA PIIONE & FAX (303) 484-0533 May 18, 1994 torm water utility ity of Fort Collins _ 63 O S /o Basel Hamadan 35 Mathews ort Collins, CO 80525 Amended Drainage Report for the Gas Station at Horsetooth Common Fort Collins, Colorado. Dear Basel: This is an amended letter to the drainage report for the proposed gas station on Lot 1 of The Market At Horsetooth Commons P.U.D. a Replat of Tract D of Horsetooth Commons PUD, in the City of Fort Collins, State of colorado. Based on our meeting and phone conversations concerning the grading platy for the gas station, where the elevation of northern driveway at the east end is at 5,081.00 which is 6 inches below the high water elevation at 5,081.50. A change to the grade of the.detention.pond will provide the needed volume which was discussed previously. The following is the grade plan with the new contour lines to provide the required volume for the detention pond with high water line set at 5,981.00. The size of the orifice to be installed at the inlet of the 15 inch storm drainage pipe is 4 inch orifice. The detention pond volume required is still the same volume for the 2 inch orifice. The allowable historical release flow of 0.50 cfs by using a 2" orifice will result into a required volume of 4,752 cubic feet. The volume needed to be retained is 4,752 cubic feet. The volume in detention pond area is the storage volume between contour line 5079.70 feet and contour line of 5081.00. The volume needed is determined using the following formula; Volume = d (A + B.+ (AB.) 1/2 ) 3 Where; d = Depth between contour line ft. A = Surface area of top contour line. B - Surface area of bottom contour line. Storage volume between contours 5,079.70 and 5,080.00 is: A = 850.00 sq. ft., Surface area at contour line 5,079.70. B = 3,081.00 sq. ft., Surface area at contour line 5,080.00. with a depth of d = 0.30 feet, Then V, = 560.00 cubic feet Storage volume between contours 5,081.00 and 5,080.00 is: A = 3,081.00 sq. ft., Surface area at contour line 5,080.00. B = 5,729.00 sq. ft., Surface area at contour line 5,081.00. with a depth of d = 1.00 feet, Then V, = 4,340.00 cubic feet .9111nn 15ION PI.;1NNING ,1ND rnsIGN - Sun..1nII 61-1,04ECn,vrC,1I. INITS716,1 nDN.S - 1:01"NU ON. 517111Cn•rrl: DI;.Srrn .1ND '070N. DRAINAGE. 1'LOOr)CONIMM 111-1n'NING AND DESIGN - IiN '1170Of iNE11..1.S.SIi.SS.1fPN1' • (alv.Sr/rrcTln.v•v.ln•.uai.lrri.v7. The drainage inlet box has the size of 2.2x3.67x3.2 which can hold..25;84 M . Then total volume of detention pond is equal to = 25.84 + 560.00 + 4,340.00 = 4,925.84 ft3, which exceeds the needed storage volume of 4,752 ft3.. If you have any further questions or need any more information please feel free to call me at (303)-484-0533. Sincerely, �............: f' '•:rl repared b V. ohamed Worayeth A Colorado Registered Professional Engineer ��� F A I . - - I , i f d t cq; V Q t Cf S e rnp :1 C r4 -12 60 b fixr) r.qrnt '0\ Cry VJALL I — � 0)3 1 57 .ri -00 w r,,j t 30 IiEnji,. -1 L -0'- 2 C, C-13) 77.32 1A 0 C U., 0 6 -'s lri,trt ';079.21 5iTz _0 L Fluor 5062. cc Cunc no ecep or 5080 st"II < -5081 22 cur� Cut # 73 N ft 1 5082 5091 -4 .17 Ci 000 5 f U) CIiUn s "ONVJC�07I,'('E -r--)RE floor tilev at 5n'�3 CIO L) T Stock Pile ft re Fe dlant topsoil durinh C N II I N0181p v co n s # ru c tjotr I it _�j 4 wcter Vaivti :I ;tin Eq)-pt il, it �3- 508.2.5 5"z, !:C. ,2 5Ce., V f L C11 AC: M2.3 05 2. -4 0:5� 7- IIIJ e PRO— a . ASPHALT 0 5083.21 it N%CQI I SANrTARY 475 sq ft. c i N . % 17 SEWER 0. MANHOLE U < ..... . IA 7� le r. 4- - 0.8 FL -r F...• L .... . ......... etnti'M 41 - , ; j j rI I NN, st k K 5032.56 ------ ell, --- --- 0A S., 1\1 crw, POI 3083.0r, 1.-AN-E ..... . c3r. vir, br x (1* "T. t A 'N •J! 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