The Highway Runoff Manual is the guidance that WSDOT, engineering consultants, and many local agencies use to design stormwater systems for transportation projects. Together with WSDOT's Hydraulics Manual, (pdf 11.06 mb) the HRM provides tools for designing effective stormwater collection, conveyance, and treatment systems for highways, ferry terminals, park and ride lots, and other transportation-related facilities.
The Highway Runoff Manual represents years of extensive research, collaboration, and negotiation by an interdisciplinary technical team of water quality, stormwater, and erosion control specialists; designers; hydrologists; geotechnical and hydraulics engineers; landscape architects; and maintenance staff. The technical team also includes several county representatives and benefits from a close working relationship with Washington State Department of Ecology (Ecology) staff, with work also contributed by consultants and outside reviewers. The technical team recognized that it is inefficient, and in some instances ineffective, to try to emulate how local jurisdictions manage runoff from residential, commercial, and industrial land uses. Consequently, their approach to developing the HRM takes into consideration that WSDOT:
- Needs a statewide approach for managing stormwater that recognizes the differences in climate, soils, and land uses.
- Has limited control of pollutants entering its right of way (including pollutants generated from atmospheric deposition, vehicle operation, litter, organic debris, and surrounding land uses).
- Highway projects are linear in nature and, as such, are faced with practical limitations in terms of locating and maintaining stormwater treatment facilities within state-owned right of way.
- Lacks funding mechanisms (such as stormwater utility fees) and land use controls (zoning and land use ordinances) available to local governments.
- Must be accountable to taxpayers to provide cost-effective stormwater facilities.
The HRM receives periodic updates to enhance content clarity as well as reflect changes in the regulatory landscape, advancements in stormwater management, and improvements in design tools.
Comments and suggestions for improving the HRM should be e-mailed to:
maurerm@wsdot.wa.gov or mailed to:
Highway Runoff Manual
Attention: HRM Program Manager
WSDOT
PO Box 47329
Olympia, WA 98504-7329
2010 Revision
2010 Highway Runoff Manual
WSDOT revised the Highway Runoff Manual, M 31-16 in May of 2010 response to the settlement of the appeal of the NPDES permit filed in April 2009. The revision includes:
Implementing Agreement
Upon issuance of the WSDOT Municipal Stormwater Permit in February 2009, WSDOT and the Department of Ecology adopted an implementing agreement (pdf 309 KB) calling for WSDOT to apply the June 2008 version of the Highway Runoff Manual throughout Washington State.
2011 Draft HRM - 30 Day Public Review
WSDOT revised the Highway Runoff Manual and is accepting comments on the draft language. Internal WSDOT comments should be submitted to navicka@wsdot.wa.gov by December 1, 2011. Public comments should be submitted following the guidance on the Ecology web page.
2011 HRM Draft - Summary of HRM revisions (pdf, 21kb)
Comment Form (xls, 19kb)
Post Publication - Compost Amended Biofiltration Swale
The Department of Ecology has approved a Compost Amended Biofiltration Swale (CABS) for general use for Basic and Enhanced treatment and conditional use for Oil Control. You can use the CABS beginning immediately in any WSDOT project requiring Basic or Enhanced treatment. If your project requires Oil Control, please contact Mark Maurer, 360-705-7260, for more information.
The design guidelines are included in the following document.
Compost Amended Biofiltration Swale Design Guidance (pdf, 149kb)
For more information, please see the GULD document at: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/use_designations/WSDOTcabfsCULD.pdf
Training
Training on the analysis methods used to design stormwater runoff treatment and flow control facilities has been incorporated into the HQ Hydraulics Section's curriculum. Training on guidance and procedures for temporary construction-related erosion and sediment control facilities has been incorporated into the Environmental Services' erosion and sediment control program curriculum. Training for applying other elements of the HRM is under development. All consultants who prepare Hydraulics Reports for WSDOT must have completed the 2008 Highway Runoff Manual training course or work under the direct supervision of someone who has completed the training. 2008 HRM training is required for WSDOT staff who write Hydraulics Reports.
HRM Electronic Mailing List
To receive e-mails announcing updates, training opportunities, and improvements in design tools, please subscribe to the Stormwater Issues listserve.
Sign up to receive Stormwater Issues e-mail updates
To receive announcements for updates to the HRM, please subscribe to the HRM Update listserve.
Sign up to receive Highway Runoff Manual M 31-16 email updates
Frequently Asked Questions (FAQs)
The HRM FAQs page answers a variety of questions about the Highway Runoff Manual.