Regulatory Mandates, Plans and Reports

Baltimore’s new MS4 Permit

Baltimore City’s storm drain system is regulated by the federal Clean Water Act, specifically, a National Pollutant Discharge Elimination System Municipal Separate Storm Sewer, also known as the (MS4) permit. The latest MS4 permit was issued to the City on November 5, 2021. This MS4 permit was developed based on Maryland’s Bay TMDL Phase III Watershed Implementation Plan and the local TMDLs (Total Maximum Daily Loads) associated with waterways in the City. This is the 5th generation of the MS4 permit issued to the City of Baltimore. Specific new conditions are as follows:

  • Street sweeping and inlet cleaning operations initiated under the previous permit must be continued at a level equivalent to 5,170 acres of impervious area restoration,
  • Additional stormwater best management practices (BMPs) must be implemented for an equivalent of 3,696 acres of impervious area restoration by the end of the permit term. A milestone schedule was also established to ensure progress throughout the permit.
  • At least 300 tons of litter and debris must be removed from the City’s storm drain system each year.
  • At least 15 public outreach efforts/year must be conducted related to stormwater pollution and flooding.
  • Monitoring resources may be leveraged by the City by participating in a pooled monitoring program.
  • A comprehensive plan for long-term watershed monitoring and trend monitoring and a Polychlorinated biphenyl source tracking plan must be developed and implemented.
  • Good housekeeping and pollution prevention plans must be developed for City-owned properties.
  • Winter management of de-icing and anti-icing materials must be improved to further reduce chlorides, a pollutant of emerging concern.

The following are documents related to the City’s MS4 Permit:

Each year, Baltimore City is required to submit an MS4 Annual Report charting its progress in meeting the terms of the permit.

A Financial Assurance Plan (FAP), which demonstrates the City’s financial ability to meet the current and proposed MS4 permit impervious surface area restoration requirements, is required to be submitted every two years.

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 (those noted with an * are too large to upload):

Planning Area

Major Watershed

Report Title

Year

Upper Back River

Back River

PDF icon UPPER BACK RIVER SWAP Vol 1.PDF

2008

Biddison Run

Back River

SW Improvement Feasibility & Conceptual Design*

2006

Herring Run

Back River

PDF icon HR Stream Master Plan_071304.pdf

2004

Moores Run

Back River

Watershed Restoration Plan*

2001

Direct Harbor

Baltimore Harbor

Watershed Characterization Report

In Progress

Masonville Cove

Baltimore Harbor

PDF icon Masonville Cove-Executive Summary.pdf

2014

Watershed 246

Baltimore Harbor

PDF icon WS 246 HARRIS CREEK SWAP.PDF

2010

Watershed 263

Baltimore Harbor

PDF icon WS263_WS263 Management Plan KCI Aug2006.pdf

2006

Lower Jones Falls

Jones Falls

PDF icon LOWER JONES FALLS SWAP.pdf

2008

Western Run

Jones Falls

Stream Assessment*

2004

Stony Run

Jones Falls

Watershed Restoration Plan*

2001

Gwynns Falls

Gwynns Falls

PDF icon GWYNNS FALLS WATER QUALITY MANAGEMENT PLAN - EXEC. SUMMARY.pdf

2004

Powder Mill

Gwynns Falls

PDF icon Powder Mill Targeted Report Final.pdf

2004

Maidens Choice

Gwynns Falls

Watershed Restoration Plan*

2001

Direct Harbor

Baltimore Harbor

Watershed Assessment

2021

Lower North Branch Patapsco

Lower North Branch Patapsco

Watershed Assessment

2021