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<br />MEMORANDUM <br /> <br /> <br />EMMONS <br />& OLIVIER <br />RESOURCES <br /> <br />To: Steve Hobbs & Chuck Johnson <br />Rice Creek Watershed District <br /> <br />From: <br /> <br />Carl Almer, Greg Graske & Marcey Westrick <br /> <br />Subject: <br /> <br />Stom1water Mm1agement for Roadway <br />Improvements <br /> <br />Date: <br /> <br />August 5, 2005 <br /> <br />The purpose of this memorandum is to provide recommended reVISIOns to the District's <br />stormwater management standards for roadway improvement projects. <br /> <br />HISTORICAL REVIEW OF ROAD PERMITS <br /> <br />Based on review of the roadway improvement and reconstruction projects penuitted by the <br />District back to 2000, it is apparent that there has been a wide range in the level of stormwater <br />management ultimately incorporated into a project. In fact, the level of stOllliwater management <br />provided for vm.ious projects ranges from 40% to 100% of the District's existing standard <br />(NURP ponding or removal efficiencies of 60% TP and 85% TSS). Tins wide range in <br />compliance is due primarily to the linear nature of the projects and to the vm.iable land uses <br />where roadway projects occur. It is also difficult to reconcile the multiple and sometimes <br />competing uses of the adjacent right-of-way (i.e. driveways, sidewalks, utilities, stormwater <br />management, etc). <br /> <br />The roadway improvement projects assessed Clli1 be categorized into three main settings, 111 <br />winch they occur: <br /> <br />. Areas served by Regional Ponding <br />. Undeveloped Areas without Regional Ponding <br />. Urban Areas without Regional Ponding <br /> <br />Within Areas served by Regional Ponding, roadway improvement projects usually met District <br />stlli1dards with the exception of minor road segments not tributary to the regional facility. In <br />some cases there was a need to expand the regional facility to meet District standards. In other <br />cases, the existing regional facility was already maximized and smaller local BMPs were <br />assessed and incorporated where feasible to supplement the regional facility's performlli1ce. <br /> <br />Within Undeveloped Areas without Regional Ponding, roadway improvement projects also <br />usually met District standards as there was land available for incorporation of stormwater <br />practices. In order to meet the standard, NURP ponds were incorporated in the design or the <br />reconstructed roadway remained as a rural-section road without curb and gutter, allowing <br />treatment in road-side swales. <br />