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HomeMy WebLinkAboutLINCOLN JR. HIGH ADDITION - SITE PLAN ADVISORY REVIEW - 13-98B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTL2) STEWART&ASSOCIATES November 15, 2000 Consulting Engineers and Surveyors Mr. Basil Hamdan Stormwater Utilities City of Fort Collins P.O. Box 580 Fort Collins, CO 80522-0580 Dear Basil, The following is the final drainage report for the Lincoln Jr. High School Classroom / Facility. Addition. The site is a 0.96 acre area on the Lincoln Jr. High School campus. It is bounded on the South by Lancer Drive, on the West by an existing driveway on the East side of the tennis courts, on the North by an existing driveway on the South side of the school and on the East by an existing parking lot. The site is in the West Vine Drainage Basin. The site slopes from West to East at approximately 1.7%. The ground cover is native grasses and weeds. The historic basin has a two year runoff rate of 0.29 c.f.s. and a 100 year runoff rate of 1.28 c.f.s.. The runoff flows East to the West curb of the existing parking lot and then South to the North curb and gutter of Lancer Drive. The runoff then flows East in Lancer Drive. The developed site will have a new building constructed and a new driveway and parking area constructed on the East side of the proposed building. The runoff from the roof of the building will drain to downspouts on the East side of the building and then to the West curb and gutter of the new driveway. A concrete pan will be constructed on the West side of the building to carry runoff from the area between the existing curb and the building South to the North curb and gutter of Lancer Drive. The new driveway, on the East side of the building, will have a high point at the approximate midpoint of the length of the driveway. Therefore there are two sub -basins for the developed site. Basin I has an area of 0.52 acres and its runoff will flow North in the West gutter of the new driveway to the South gutter of the driveway on the South side of the school. That runoff flows Southeasterly to a slot in the curb at the Southeasterly end of the small existing parking area. The runoff flows into the existing grass open space which is a small stormwater detention area. It has a 4 inch diameter P.V.C. outlet pipe. I have not been able to determine where the discharge of the pipe is. The two year runoff rate from Basin I is 0.90 c.f.s. and the 100 year runoff rate is 5.04 c.f.s. Basin 11 has an area of 0.44 acres and its runoff will flow South from the high point in the West gutter of the new driveway to the North gutter of Lancer Drive. The runoff then flows East in the Lancer Drive North gutter and South in the East gutter of Lancer Drive to the Vine Drive borrow ditch. The two year runoff rate from Basin H is 0.57 c.f.s. and the 100 year runoff rate is 3.04 c.f.s.. It is not possible to detain the Basin H runoff in the grass open space due to the existing elevations of Lancer Drive. If you have any questions regarding this report, please call. Sincerely, Richard A. Rutherford, P.E. & L. S. RAR/meh James H. Stewart and Associates, Inc. 103 S. Meldrum Street • P.O. Box 429 • Ft. Collins, CO 80522 970/482-9331 • Fax 970/482-9382 . SGlieil lr,j• �� I i ! i • i {VIIU i , Dr. -- i ' 4t i il/0y' llehi7 YC rr_ 1TCC.......... - F; _ = m! _� LIE<tj Cty'I Sletllt4 LC. J ��•.� I tt���- • •�•w I-a<—TIt.W St. I Unto 1�1 . �' ai:i'. �O►.� { W.Pat Dr. I I �I —j M. Time D«.r_ic @ Qti , LUPO it ail 21 V. q _spat »I' •'b��1 I I v" '` `j ' 7{ s as j� I ! it I M j �• .. I Lb.. _ i 4 1i C4.�. I Sys i I a 0. it y f . >i i'• aid'-e - iRT..'`{ I Mal-� RL r �.- -.1 -.n{ iJ - 1. I o, y o POL iyyu I .wit LMN me St. C -Z'r� I f i�" iTt. 11. St. nl• - ..l �yY.�� ,u' .. �. Sa.e'"fL, I �(� •:.;G. -M`c�'CVd.?3' <9 r su -MN ..! F �� r. as �. lauat �W R Kt I = +_ _•-Z• " �► a� ,ai �. - C1.... I I aJ, D' Riagld44; �� } �.I it ft4Dc � ..1 I�f i adDr � sr O• } Ix � 3 na etiti took �c I ,_� - UE w �. � MMAI, u St.a� All 1- Jy g,' - i a .0 1h 'ra�V`" !i v'��, ${,r� PO L �d "� d,, •Pe lm ,\ i "�.... I NC up�"To •y �f �-'"4 .. r >, . ` t « a.4t_"V is • . t Iy 4t;C�[._� M'smW.,n�.�y�1y '•CGw WSwe_ S = ,�" SWeasrt a ud or �vyJ r.w .tom SGr.Ch,•� S '�P• 4� it .Ct.M4w FINAL DRAINAGE REPORT FOR LINCOLN JR. HIGH SCHOOL CLASSROOM/FACILITY ADDITION WEST VINE DRAINAGE BASIN PREPARED FOR POUDRE SCHOOL DISTRICT NOVEMBER 14, 2000 PREPARED BY STEWART & ASSOCIATES 103 SOUTH MELDRUM STREET P.O. BOX 429 FORT COLLINS, CO 80522 TEL. 970-482-9331 FAX. 970-482-9382