Regulatory Mandates, Plans and Reports

Baltimore City, like other local governments, must put together a stormwater management program, subject to terms of the federal Clean Water Act and approval by the state. This is a condition of the City’s National Pollutant Discharge Elimination System Municipal Separate Storm Sewer (MS4) permit.

Since Baltimore is part of the Chesapeake Bay watershed, it must comply with strict regulations regarding polluted runoff. As part of our MS4 stormwater permit, the City must attain specific measures of runoff control by the end of 2018. Among those measures, Baltimore must restore an equivalent of 20 percent of its impervious surface to the maximum extent possible. Even public education and involvement regarding water quality is covered by the terms of our permit. Baltimore’s program to meet the requirements of the MS4 Permit is outlined in a document called the “MS4 and TMDL Watershed Implementation Plan”. A “TMDL” (Total Maximum Daily Load) is a regulatory term that describes the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards.

As part of the MS4 Permit, the EPA approved a "Trash TMDL" for the Middle Branch and Northwest Portions of the Patapsco River, roughly from Harbor Hospital in the south to Ferry Bar Park (Middle Branch) and Tide Point to Canton Waterfront Park (Northwest Portion).

Watershed Assessments

To restore a watershed, there must be a Watershed Plan. The MS4 Permit requires that, by the end of the permit term, Baltimore City shall complete detailed watershed assessments for the entire City. The following is a list of the previous assessments:

Planning Area

Major Watershed

Report Title

Year

Upper Back River

Back River

Small Watershed Action Plan

2008

Biddison Run

Back River

SW Improvement Feasibility & Conceptual Design

2006

Herring Run

Back River

Stream Assessment & Restoration Concept Plan

2004

Moores Run

Back River

Watershed Restoration Plan

2001

Direct Harbor

Baltimore Harbor

Watershed Characterization Report

On Hold

Masonville Cove

Baltimore Harbor

Small Watershed Action Plan

2014

Watershed 246

Baltimore Harbor

Small Watershed Action Plan

2010

Watershed 263

Baltimore Harbor

Management Plan

2006

Lower Jones Falls

Jones Falls

Small Watershed Action Plan

2008

Western Run

Jones Falls

Stream Assessment

2004

Stony Run

Jones Falls

Watershed Restoration Plan

2001

Gwynns Falls

Gwynns Falls

Water Quality Management Plan

2004

Powder Mill

Gwynns Falls

Targeted Watershed Assessment

2004

Maidens Choice

Gwynns Falls

Watershed Restoration Plan

2001