Action: Increase capacity of the river in high risk areas to provide flood risk reduction to at least the 1% (100-year) annual chance flood event or to a level recommended by a risk assessment.
Levels of flood risk management vary along the 51-mile channel. The 1% (100-year) event is used as a target in this plan because it is the standard for the National Flood Insurance Program (NFIP) and studies show that using this standard can, on average, save $7 for every $1 spent on flood mitigation for riverine environments.[mfn] National Institute of Building Sciences, Natural Hazard Mitigation Saves: 2017 Interim Report,page1.[/mfn] Future local risk assessments may indicate that capacities should be increased. One way to reduce flood risk in communities near the LA River is to increase the conveyance capacity of the river, so that it can safely pass larger storm flows to the Pacific Ocean.
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Methods
specific, tangible ways to reach the goal
A worker removes invasive plant material from the channel near the Glendale Narrows, a maintenance practie that helps to increase the flood capacity of the LA River.
US Army Corps of Engineers, LA River Arundo Removal, 2004.