Low Impact Development (LID)

Low Impact Development (LID) is defined as a design strategy to maintain or reproduce the way storm water infiltrates or runs off a site before development occurs. LID principles control storm water runoff by using small scale landscape based features that are distributed throughout the site. Projects designed following LID principles must maintain the undeveloped volume of storm water runoff and mimic the natural water balance through infiltration, evapo-transpiration, or through capture and reuse of storm water.

LID is intended to minimize the impact of development —our buildings, roads, parking lots, driveways— on our watersheds. LID correlates the relationship between storm water runoff and the land, including our built environment. LID techniques lessen the the quantity of runoff and improve its quality by "slowing, spreading, or sinking" runoff on the site as much as possible. Slowing down storm water runoff  keeps the water in the channels from rising too high and too fast and devastating communities downstream. Spreading does the same, helping to dissipate the storm water's power. Sinking means infiltrating water through soil, which cleans the water and recharges the groundwater table.

The City's MS4 permit requires compliance with the City of Santa Rosa and County of Sonoma's LID Technical Design Manual (dated 2017). Adherence to these guidelines requires new development projects to incorporate LID design strategies and BMPs to reduce pollutants in runoff to the maximum extent practicable. For more information, please visit the City of Santa Rosa, Storm Water LID Technical Design and the California Stormwater Quality Association webpages.