Storm Water Management

U.S. Army Corps Flood Risk Management Study Public Scoping - September 30, 2020

FEMA - Elevation Certificates Who Needs Them and Why

Information on Flood Insurance

What is an Illicit Discharge?

An illicit discharge is any discharge to the storm sewer system that is not composed entirely of stormwater (rainwater or snow melt), except for discharges allowed under a National Pollutant Discharge Elimination System (NPDES) permit. *

Examples of illicit discharge include:

• Sand and dirt from construction sites washing into drains

• Dumping toxic chemicals into drains (motor oil, paint, pesticides, etc.)

• Chemical and fuel spills

• Overuse of fertilizers and pesticides

• Pet waste

• Trash

• Yard waste

If you notice an illicit discharge, immediately
call MSD’s 24 hour hot-line: 314-768-6260

See the full MSD brochure on the Illicit Stormwater Discharges page


The purpose of the St. Louis County Phase II Stormwater Management Plan is to improve area water quality by preventing harmful pollutants from being carried by stormwater runoff into local water bodies. The Metropolitan St. Louis Sewer District (MSD) partners with 59 municipalities (co-permittees) to comply with stormwater permit requirements for the St. Louis Metropolitan Small Municipal Separate Storm Sewer System (MS4).
MS4 General Overview
St. Louis County Ordinance 1974, As Amended Title XI - Land Disturbance Code
Major Land Disturbance Questions and Complaints
To read more about stormwater management, please visit Metropolitan St. Louis Sewer District website.   MSD - Ordinance No. 15048 Illicit Discharge

Managing Storm Water Runoff

As more and more people own cars, more parking lots become necessary. Unfortunately, parking lots can adversely affect the environment as well as detract from community character. Paved parking lots are typically designed to collect and concentrate large areas of storm water runoff, which can impact a receiving streams hydrography as well as water quality. Paved parking lots can generate heat, raising the surrounding areas air temperature and the temperature of the first flush of storm water, creating significant ecological impacts. Therefore, careful attention to their design will go a long way toward protecting your community's water resources. Permeable pavement is a good solution to storm water pollution from parking lots.