This document discusses how low impact development (LID) techniques can help address multiple water quality compliance issues simultaneously. LID aims to mimic pre-development hydrology to avoid habitat impacts and provide ongoing stormwater treatment. While LID definitions and applications have evolved, it can help meet requirements of Municipal Separate Storm Sewer Systems and Total Maximum Daily Loads for pollutants in a cost-effective way. The document outlines both improvements in LID guidance as well as ongoing regulatory challenges regarding issues like groundwater protection and long-term performance.

1. the clean water act national
pollutant discharge elimination
system permit and total maximum
daily load programs’ convergence
towards the of low impact
development techniques to satisfy
multiple compliance dilemmas
or, why acronyms are sometimes ok

2. LID
• Low Impact Development (what it originally
meant):
– Mimic the pre-project hydrology (rate, time of
concentration, and volume) at the site
– Avoid habitat impacts by site design
– Use natural processes to provide ongoing
“treatment” of storm water from site

3. What LID means now
• ?
• 5% effective impervious area (EIA)
• Use my proprietary model to design features
• Engineered boxes in the ground designed to
infiltrate
• “True” pollutant source control techniques
(great idea, but not LID)
• Site by site vs. regional controversy

4. Current Problems Looking for
Solutions
• Municipal Separate Storm Sewer System
(MS4) compliance with Receiving Water
Limitations (RWLs) – aka, “the iterative
approach is broken”
• TMDLs for many pollutants associated with
runoff
• Cost of compliance with all this stuff
• Oh, and water supply. ..

5. LID, or the CWA Honey Badger

6. LID…
• Eats trash
• Chews up pollutants of
all types
• Recharges aquifers in its
sleep
• Is low maintenance
• Just sounds cool
• Don’t cost an arm and
leg (if you are nice)
• Don’t care about
political boundaries

7. Improvement
• Making someone “do LID” is better than most
alternatives.
• LID requirements and guidance is getting
better, generally.
• LID and related techniques are converging on
common metrics and expectations.
• Water supply interests will further drive LID to
become common practice, I predict.

8. Risk Management Topics,
Regulatory Style
• Groundwater vs. surface water protection
• SW credits – markets, trading and accounting
fraud opportunities, abound
• Tracking and oversight of projects, acre-feet
recharged, etc.
• Water rights
• Long term performance of installed features
• LID is often a surrogate for many interests

9. Related Water Board Projects
• RWLs for MS4s
• TMDL Implementation Requirements
– Caltrans, Phase II, IGP, etc.
• IGP – BAT/BCT equivalency?
• Trash Amendments
• Ground Water Strategy and Storm Water
Strategic Workplan (coming soon)

10. National Projects and Websites
• Impervious Cover TMDLs
– http://clear.uconn.edu/projects/TMDL/
• Center for Watershed Health
– http://www.watershedhealth.org/Default2.aspx
• The Green Solution Project
– http://www.conservationsolutions.org/greensolution.
html
• Washington DC SW Credit Market
– http://green.dc.gov/release/district-proposes-new-
river-protecting-stormwater-management-standards