Laserfiche WebLink
M- <br />1 2000 16:33 FR BRRR ENGINEERING 952 832 2601 TO 92494616 <br />Barr Engineering Company <br />4700 West 77th Street • Minneapolis, MN 55435-4803 <br />Phone: 952-832-2600 • Fax: 952-832-2601 <br />P.02/03 <br />BARR Minneapolis. MN • Hibbing. MN • Duluth. MN • Ann Arbor. Ml • Jefferson City. MO <br />September 11,2000 <br />r <br />5* <br />t*/.r: <br />Mr. Paul Weinberger <br />City of Orono <br />2750 KeUey Parkway <br />PO Box 66 <br />Crystal Bay, MN 55323 <br />Re: Brenahtll Homes Development Proposal <br />Dear Mr. Weinberger; <br />meeting. Based on our latest review, we continue to have concerns regardmg the steep slopes and <br />wetland losses. <br />St60p Slopes and Erosion Concerns <br />The revised development plans include a rcconfigiiration of the lot line between Lots 2 and 3 and a <br />minor reduction in the cul-de-sac length as recommended by city staff. However, Ae plans do not <br />adequately protect the slopes and ravine from erosion due to concentrated ^off from the backs and <br />sides of the homes. Unfortunately, approximately onc-half of the house pad on Lot 2 ud ^ <br />approximately one-sixth of the house pad on Lot 3 lie within areas defined as steep slopes (8*0P« <br />sfeeper than 12%). The current plans have not altered the dr^age to ensure <br />does not cause erosion in the south ravine and on the steep slopes leadmg to Wildhurst Trail. <br />The south stormwater pond is also planned for construction within the south ravine in are^ cu^ntly <br />containine slopes steeper than 18 percent. The construction of the south pond would req^e *e <br />removal of numerous large maple trees which are currenUy providing stability in the ravme. The <br />steep slopes on Lots 2 and 3 are currently protected from erosion by: <br />1 The full tree and shrub canopy which intercepts rainfall, maintains a more permeable soil <br />structure and wicks away moisture from within the soUs by evapotranspirarion. and <br />2 The natural surface roughness and small depressional areas in the upstream dr^nage area slows <br />any runoff that does occur so runoff within the ravine is spread out and maintained at lower <br />rates. <br />As the city staff recommended at our meeting on September 6,2000, a conservation easement should <br />be provided over the steeper slopes on Lots 2 and 3 to protect the existing vegetative coirer and <br />around elevations. The pond would also create a new slope into the ravine which would be s^per <br />Uian 20 percent. Constructing the pond within a flatter area would eliminate smaller trees and create <br />less of an erosion concern.