(This image shows three different types of permeable paving: asphalt, concrete, and pavers.)

What is Low Impact Development?

Low Impact Development (LID) is a stormwater management strategy that emphasizes both structural and non-structural infiltration based best management practices (BMPs) in an attempt to conserve natural site features and mimic natural hydrologic conditions. Examples of LID BMPs include permeable pavement, bio-retention and tree wells. 

LID Infeasibility Study

In an effort to help mitigate the economic impacts of the state/federally mandated Low Impact Development requirements that went into effect in 2017, the City hired Aspect Consulting to conduct a LID Infeasiblity Study. They also developed LID infeasibility maps based on the LID infeasibility criteria contained in City's adopted stormwater standards (SeaTac Municipal Code 12.10.010).The following Work Products were developed: 

• LID Infeasibility Study Report
• LID Infeasibility Criteria Checklist
• LID Infeasibility BMP Maps (see map links below)

LID BMP Infeasibility Maps

(INTENDED USE OF LID BMP INFEASIBILITY MAPS)

These maps are intended to be used to demonstrate the extent of infeasbility by LID BMP type on public or private property based on existing data. Development applicants may use these maps to help demonstrate the extent known LID infeasibility on their property and to assist in locating areas where LID BMPs may be feasible. It is not intended for these maps to be the sole authority for determining LID infeasibility, and the City is not required to use these maps as such. If these maps are used as a part of a development application, Engineering Review staff will field confirm the infeasiblity data. Please see the full Disclaimer Language for further details. 

Link to Infeasibility Maps 

Instructions on Use of Web Maps

Focus Sheet for Developer Applications

Below are links to our LID BMP Infeasibility Interactive Web Maps.