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II I I 44 Through the MartIn Park area a wIde grass lined channel Is utilized, as adequate space is available. Between Martin Drive and the Turnpike a lined, European type channel with higher velocity flow must be used. I I I I I Through the University of Colorado property between the Turnpike and Baseline Road a wide, shallow, landscaped channel is used where possible, reducing In width to a European type channel near Basel'ine. This area, which includes a storage pond, should be developed to fit in with land- scape planning for the University. Between Baseline Road and Mohawk a drainage easement exists, although of limited width. The channel has been designed with 3:1 side slopes, relatively deep flows, and minimal freeboard to restrict construction to the existing right-of-way. Flow Is allowed to spread onto adJacent property so long as buildings are not damaged. I I , I II I I I I i I I I From Mohawk to Boulder Creek a typical grass lined channel with 4: I side slopes is utilized, A crossing of the Wellman canal is accomplished by passing the Bear Creek channel over the Wellman at its existing flow line. A maJor culvert crossing of the proposed 47th Street project and a brIdge crossing of Arapahoe Avenue will be required. The existing condition of Boulder Creek makes it impossible to design a channel for lower Bear Creek without some flooding of adJacent property, Therefore an Interim channel is proposed for the existing condition of Boulder Creek, with the final channel design based on a lowered invert of Boulder Creek. Viele Channel. Channel work begins on Viele Lake by improving the exist- ing channel and culvert capacity from 50 cfs at VIele Lake to 500 cfs at Broadway. At Broadway 2 acre feet of storage will occur and lower the dIscharge to 400 cfs. The channel and culverts to 46th Street shall be improved to carry this dIscharge. The culvert under 46th Street and existing downstream channel will be Improved to carry 500 cfs. The exist- ing channel will change into a grass lined section just above the Bear Creek Ditch and then pass under the ditch and by a side channel detention pond on the Tantra property. The channel then winds down to the future 47th - Denver - Boulder Turnpike Interchange which is the site of a com- plex storage and sedimentation pond system. After passing under the Turnpike the channel joins the Anderson Channel and flows to South Boulder Creek in a grass side, lined bottom section. Special arrangements will be made for ditch flows. Anderson Channel. Improvement shall begin at the intersection of Moore- head Avenue and Table Mesa Drive with collection conduits to the exist- Ing Anderson Ditch. Flood waters then shall pass into a small pond system that allows the use of an existing culvert under the Denver-Boulder Turnpike. ThIs detention pond Is an exIsting sump located near the ramps servicIng Denver bound traffic. The existing channel will be replaced with a culvert under the future 47th Street Bypass. Downstream channel of this area will be Improved and lined as necessary to the con- fluence with VIele Channel.