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HomeMy WebLinkAboutDrainage Reports - 05/01/1992r N May 1, 1992 Project No: 1098-53-92 Fig -al Approved Report Glen Schlueter Date City of Fort Collins Storm Drainage Utility P.O. Box 580 Ft. Collins, Colorado 80522 Re: The Pavillion at the Marriott, Ft. Collins, Colorado Dear Glen, The Pavillion at the Marriott will consist of a 44' x 83' structure over the existing wood deck on the southeast side of the Marriott Hotel. The structure would result in an additional impervious area of 3652 square feet (0.084 acre) to the 9.2 acre drainage basin as defined in the final drainage report for the Marriott. The drainage report for the Marriott, titled "Drainage Plan for Marriott at Fort Collins" was prepared by Simons, Li & Associates, Inc., Project No. CO-RMV-03, latest revision date February 21, 1983. The area of the new structure represents less than one tenth of one percent of the 9.2 acre drainage basin (0.084/9.2). The structure will therefore have a negligible impact on storm drainage for the Marriott site, and even less of an impact on the overall Foothills Basin Master Drainage Plan. For example, the structure would increase runoff from 1.12 cfs to 1.15 cfs (2.6%) for a 10-year storm within the immediate 0.69 acre sub -basin (sub -basins 4 and 5) of the Marriott Drainage Plan to which the structure runoff initially contributes. Attached is a copy of revised calculations for Design Point 5, and a copy of the Marriott Drainage Plan from the Simons -Li drainage report. The Marriott site drainage is undetained and releases to Warren Lake (See Foothills Basin Master Drainage Plan). If you have any further questions regarding and its potenti impact on storm drainage, Sincerely Brian W. Shear, P.E. Shear Engineering Corporation BWS/so cc: Jim Alldredge, The Marriott City of Fort Collins Planning Department the Pavillion at the Marriott please call. cjp: \q�yy\nF IF(LSy FQ %: ' `° 20262 SS/ / ONAnnu���° 4836 S. College, Suite 12 Fort Collins, CO 80525 (303)226-5334 S,NONS ua assOCurEs CLIENT JOB NO. PAGE/A7 � - ENGINEERING CONSMTMTS PROJECT DATE CHECKED DATE ' FORT COLLINS. COLORAW DETAIL . CHECKED BY COMPUTED BY - DIES/ 4 Al /N-r Sl,b-bus�� i 5=l0/0 Pun =�cc).4s�6J,15) 's I., (A S11kca C�s cSrC�nl ?Of 'fir -s- - S,6-,a s,V% �, o Lam) C► • � G'. 7 ):, o •G 4� _1-1��c,�s / �Sc,�'s �- i is -EAST MONnE_ORlu \/ �«•s., I ��� Total area analysiscondered in site dr �^'--- — O• � Sub -basin boundary OSub -basin number Design Point x I .....' • .. 's., \ �,. / Roof drain A .._�. _ li 0: ' — \ i.a✓_�- •fin . \ 1 / • Z CO Ole \ — - I� i OSCAPECY `1� 44 1 3 Figure 1. Overlot grading and drainage plan. ItI i; \'� _ / n,�eeiorr�r�oPrto�cnvs -✓..'1177ww- n..✓ 1` ` \—Ii \ ^'{uv. Jr{ OVEILOTGRAQ/A.G %GPA/,ViIGC PG.tN �� ` - Ii� I I}� � 1 CMSMH ✓!• InR.ti ff-61✓-{•