North Valleys Flood Control Study
Silver Lake and Swan (Lemmon) Lake
Regional Water Planning Commission - Video
Regional Water Planning Commission - Audio
The city of Reno needs to understand the potential extent of flooding likely to occur under present development conditions and expected future development conditions.
Closed basins, such as the Silver Lake and Swan (Lemmon) Lake Playas, are sensitive to flooding. The floodwaters do not flow out of the basins, but recede only by infiltration (soaking into the ground) and evaporation; therefore, a large flood in either basin might take months to go away.
With increased development, areas of infiltration are decreasing; while areas of accelerated runoff are increasing.
With the increased likelihood of flooding, the leading possibilities for mitigation are dredging at an estimated cost of $ 74 million to 158 million with redefining flood and playa elevations. [Who and by what mechanism will pay the cost, is unknown.]
Swan Lake
To mitigate future development in the Swan Lake watershed, Quad Knopf is recommending retention ponds and/or excavation [dredging] of select areas in and around the playa.
Silver Lake
To mitigate future development in the Silver Lake watershed, Quad Knopf further recommends an Infiltration Facility on Airport Authority property, with adequate capacity in the Effluent Reservoir (proposed by Eco:Logic) to include 718 acre feet of storm water volume and excavation of selected areas in and around the playa.
This flood mitigation study performed by Quad Knopf, headquartered in Visalia, Calf.
http://www.quadknopf.com/
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