Final Scope

The Municipal Separate Storm Sewer System (MS4) permit requires state DOTs to develop and implement stormwater management programs to meet Section 402 - National Pollutant Discharge Elimination System (NPDES) requirements of the Clean Water Act. The MS4 permit places requirements on the management of stormwater quality and allows state DOTs to discharge stormwater runoff from their storm sewer systems to Waters of the US or state regulated waters. State DOTs must maintain adequate funding and resources to meet the requirements of the permit.

The state DOT MS4 stormwater programs are subject to risks, such as:
• budget shortfalls;
• project overruns;
• increasing permit requirements;
• allocation of funds to address emergencies or non-compliance situations; and
• staff turnover with the associated loss of institutional knowledge.

To address these risks and uncertainties, state DOTs currently implement a wide variety of budget development and program cost determination practices and procedures.
The objective of this synthesis is to document current state DOT MS4 budget development, prioritization, and allocation practices.
Information to be gathered includes (but is not limited to):

• MS4 stormwater program budget funding source(s);
• Existence of written guidelines or procedures for developing MS4 stormwater program budgets (e.g., responsible staff, frequency of updates);
• Methods to forecast MS4 stormwater program administrative, management, research, and implementation needs, subsequent budget;
• Does your budget include contingencies for risks, such as: aging infrastructure, natural disasters, human impacts, policy changes;
• Innovative approaches for funding, collaborative approaches to get funding – maintenance of facilities by non-DOT entities;
• Process for developing the MS4 stormwater program budget; including allocation and prioritization;
• Budget allocation for tools to support MS4 compliance, e.g. GIS, software, asset inventory, consultant services, databases;
• Management practices for MS4 stormwater program budgets (e.g., frequency, performance metrics, and revisions);
• Process/practices for updating budget allocation due to regulatory changes; and
• Programs funded by the MS4 stormwater program budget.

Information will be gathered through a literature review, a survey of state DOTs, and follow- up interviews with selected DOTs for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.

Information Sources (Partial)

• National Municipal Stormwater Alliance (NMSA) – Web page link - https://ms4resource.nationalstormwateralliance.org/index.php/determining-program-costs/#Topic%203
• AASHTO. (2010). Cost and Benefit of Transportation-Specific MS4 and Construction Permitting.
• Taylor, S., et al. (2014). NCHRP Report 792: Long-Term Performance and Life-Cycle Costs of Stormwater Best Management Practices. National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press. https://doi.org/10.17226/22275.
• Whitman, J.B., and Perez, M.A. (2024). NCHRP Synthesis Report 614: Outsourcing Post-Construction Stormwater Best Management Practice Inspection and Maintenance Activities. National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press. https://doi.org/10.17226/27502.
• Dong, R., Nelson, J., Cummins, S., and Goodall, J. (2023). “Tracking the Cost of Maintaining Stormwater Best-Management Practice Facilities: The Role of Database Design and Data Entry Best Practices.” Journal of Sustainable Water in the Built Environment.

TRB Staff (Consultant)
Sandra Q. Larson
Email: slarson@nas.edu & Phone: 515-971-6329

Meeting Dates
First Panel Meeting: February 26, 2025
Teleconference with Consultant: April 9, 2025, 2-3 pm eastern
Second Panel Meeting: November 6, 2025, Washington D.C.

Topic Panel

Maria Briones, Massachusetts Department of Transportation

Eileen E Dunn, Arizona Department of Transportation

Jennifer Marie Green, Florida Department of Transportation

Becky Humphreys, Ohio Department of Transportation

Stephen M. Sisson, Delaware Department of Transportation

Nicklas "Nick" Tiedeken, Minnesota Department of Transportation

Gregory Granato, Federal Highway Administration (FHWA)