Agenda - Council - 10/12/2004 - Laserfiche WebLink

Home

CASE CONSIDER JUNIPER RIDGE DRIVE/151sT AVENUE STORM WATER MODIFICATIONS By Steven J. Jankowski, City Engineer Background: In 2000 modifications were made to the storm sewer system along a portion of Juniper Pddge Dfive which included the segment from 151st Avenue south to the cul-de-sac. A part of these improvements included the construction of an emergency outfall to the Rttm River, wh/ch would be utilized dufing extreme precipitation events. A part of the normal operation 6f the storm water system calls for the ponding of water within a fifty foot drainage and utility easement located along the northerly side of the lot located at 15000 Juniper Ridge Dfive. This ponding area also has as its phmary discharge point another outlet which flows into the pond located between Torito and Ute Streets in the adjacent Juniper Woods subdivision. Subsequent to the. 2000 project, a garage was cohstructed on this lot just be.yond the easement. During a recent storm event, storm wate? ponded beyond the easement and came within' a couple of feet of the newly constructed garage. Staff perfon'ned some survey work and determined that the outlet weir was set at an elevation which would cause water to pond beyond the drainage and utility easement prior to discharging through the emergency outfall to the fiver. In view of the above, staffhas requested the design engineer do a review of the design criteria to . dete~anine the extent to' which the weir on the emergency outlet ~hould be lowered. It is also anticipated that additional ponding volume-will be required Within the drainage and utility easement to ensure the peak elevation of ~he 100 year flood will be contained within the easement. It is anticipated that the con'ective work will include; lowering the weir-elevation, increasing the pond areas volume, and filling and resodding a portion of the yard at 15000 Juniper Ridge Drive, It is knticipated that all work, excepting the landscaping will be performed by the Public Works depa.rtment. The cost of the landscaping work should be less than $1,000. Recommendation: Staff recommends that an analysis of the drainage basin be conducted and that necessary con'ective actions be taken to ensure that the 100 year precipitation event is contained within the drainage and utility easement at a contracted construction cost not to exceed $1,000 which shall come from the storm water utility. Action: Motion to recommend to City Council that an analysis of the di-a/nage basin be conducted and that necessary corrective action are taken to ensure that the 100 year precipitation event iS contained within the drainage and utility easement at a contracted construction cost not to exceed · $1,000 which shall come from the storm water Utility. Reviewed By: Public Works Director/Fire Chief Assistant Public Works Director 'Street Maintenance Supervisor PW: 09/21/04