25 October 2004
LID SITE PLANNING PROCESS
INTRODUCTION. This is a representative process for planning LID retrofits.
Individual facilities will have unique needs and should adapt this process accordingly.
MODEL PLANNING PROCESS.
Step 1: Define project objectives and goals
1. Identify the LID objectives for the project. Consider these four
fundamental aspects of stormwater control:36
Peak runoff rate
Flow frequency and duration
2. Evaluate existing stormwater infrastructure in terms of how well it
functions with respect to each of these aspects.
3. Determine the goals and feasibility for control of runoff volume, flow
frequency and duration, and water quality; as well as on-site use of
stormwater (e.g. irrigation).
4. Prioritize and rank basic objectives.
5. Define hydrologic controls required to meet objectives (i.e. infiltration,
Step 2: Perform site evaluation and analysis
A site evaluation will facilitate LID design development by providing site
details that will assist in the development of an LID program.
1. Conduct a detailed investigation of the site using available documents
such as drainage maps, utilities information, soils maps, land use plans,
and aerial photographs.
2. Perform an on-site evaluation highlighting opportunities, such as pollutant-
generating areas, potential disconnects from combined sewer systems,
and potential green corridors. Note potential LID practices and areas
where water quality and quantity controls could be installed.