USDA Forest Service

Pacific Southwest Research Station

 
Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Quantifying the potential for a low-cost, distributed stormwater detention system using LiDAR and remotely-sensed data

Principal Investigators:
Geoff Schladow, University of California-Davis
Juan Francisco Reinoso, University of Granada
Carlos Leon, University of Granada

Proposal [pdf]

Final Report [pdf]

Project Summary

LiDAR data, acquired for the entire Lake Tahoe basin through the Southern Nevada Public Lands Management Act (SNPLMA), offers many opportunities to better understand the spatial characteristics of the watershed. This project sought to utilize these LiDAR data and other remotely sensed data to identify and quantify the potential to develop stormwater detention and infiltration areas based on small-scale patterns of land topography. Utilizing the high vertical accuracy and resolution inherent in the existing LiDAR data set, we have demonstrated for the first time that it is feasible to identify the hydrologic connectivity and the topographic features of the urban areas and the wildlandaurban interface (WUI) areas. Based on this information the cumulative volume of a distributed detention system, achievable by small-scale construction of earth retaining walls in conjunction with features of the existing topography has been quantified. Remotely sensed data and current GIS layers show whether these detention basins intrude on private property, existing infrastructure, sensitive lands etc.

The methodology has been developed and tested for two locations: Incline Village, NV, and South Lake Tahoe (CA and NV). For Incline Village the analysis showed that a system of 1300 distributed detention basins could detain (and potentially infiltrate) approximately 49,000 m3 of stormwater in the urban area. Such a system would be capturing water from 56% of the urban area. For South Lake Tahoe the analysis showed that a system of 1600 distributed detention basins could detain (and potentially infiltrate) approximately 1,200,000 m3 of stormwater in the urban area. Such a system would be capturing water from 42% of the urban area. The current system of 192 detention basins in South Lake Tahoe cover an area of 218,000 m2. The addition of the full number of distributed detention basins would cover over 1,000,000 m2.

These estimates on the potential number of distributed detention basins are an upper bound. Ground truthing and comparison of existing infrastructure (e.g. hidden culverts), as well as eliminating sites with low permeability soils, would likely reduce this, as would finer scale assessment of private property and other considerations. Needless to say, even a 50% deployment of distributed detention basins would have a huge impact on stormwater capture rates. It would also do this in a way that had minimal visual impact, would require minimal planning and permitting delays, would utilize public lands fully to provide protections to the streams and the lake, and would provide seasonal wildlife habitat.