Fact Sheet A4 – Source Control Strategies for Ditches
Method
Description
Manage Soil Erosion from Uplands
Minimize sediment entering ditches by controlling soil erosion at the source
through increased infiltration or sediment management practices such as:
Designate a Ditch Buffer
Restrict or exclude agricultural crop and livestock production from the
public road right-of-way and its associated roadside ditch to prevent direct
applications of fertilizer, manure, or pesticides in the ditch zone.
Street Sweeping
Perform street cleaning (typically sweeping with a regenerative air or
vacuum sweeper) to clean the adjacent roadway surface and to reduce
sediment loading into ditches.
Catch Basin Cleaning
Clean catch basins that may be associated with a ditch inlet to reduce
sediment loading into ditches.
No-till or conservation tillage
Contour farming
Contour buffer strips
Cover crops
Direct seeding
Field borders
Design of agricultural ditches
to avoid pollution sources
What is Source Control?
Source Control
Strategies for
Ditches
Fact Sheet A4
Source control refers to practices that prevent or reduce pollutant generation rather than treating or
removing pollutants already captured by stormwater runoff. Methods for preventing pollutants from
entering a ditch and preventing generation of pollutants in a ditch are described in this fact sheet.
Prevent Pollutants from Entering a Ditch
February 7, 2019
Fact Sheet A4 – Source Control Strategies for Ditches
Method
Description
Minimize Cleaning Activities
During the Wet Season
Conduct ditch maintenance in the later spring, summer, or early fall, where possible to
allow re-establishment of vegetative cover and minimize erosion.
Control Sediment Loading
During Vegetation
Establishment
Install preventative measures (e.g., check dams, straw mulch, or silt fence) to reduce
downstream sediment loading while establishing new vegetation. Seed and/or plant
during the following optimum windows:
Late spring (April 1 through June 30)
Early fall (September 1 through October 1)
Eliminate or Reduce
Herbicide Use
Use physical and/or mechanical methods of vegetation removal rather than applying
herbicides, where practical. If herbicides must be used, apply early in the summer.
Guidelines for Stream and Ditch Maintenance (Oregon Department of Agriculture, 2018): www.oregon.
gov/ODA/shared/Documents/Publications/NaturalResources/GuidelinesStreamDitchMaintenance.pdf
Re-plumbing the Chesapeake Watershed: Improving Roadside Ditch Management to Meet TMDL Water
Quality Goals (Schneider and Boomer, 2016):
www.chesapeake.org/pubs/349_Boomer2016.pdf
Draft Options for Crediting Pollutant Reduction from Roadside
Ditch Management Practices (RDM) in the Chesapeake Bay
Watershed (Chesapeake Bay Roadside Ditch Management
Team, 2017): www.chesapeakebay.net/channel_files/24809/
attach_b_062017_rdm_memo_draft.pdf
Drainage water management for water quality protection
(Strock et al., 2010):
www.jswconline.org/content/65/6/131A.full.pdfestablishment.
Why is Source Control Important?
When is Source Control Needed?
Source control is the first step in reducing pollutant loads that enter ditches or are generated in ditches through
installation and maintenance activities. The goal of source control is to implement cost-effective approaches to
improve stormwater runoff quality. Source control strategies may result in an improvement in water quality in
ditches without installing more costly treatment practices downstream.
When ditches receive direct runoff from pollutant-generating land
uses such as agricultural fields.
When ditches lack natural buffers to prevent stormwater runoff
with high pollutant loads from entering ditches.
When routine maintenance such as ditch cleaning, ditch reshaping/
regrading, and vegetation establishment is being implemented.
Additional Resources
Prevent Generation of Pollutants in a Ditch
This fact sheet was developed by Herrera Environmental Consultants with input from King County and the Regional Operations and Maintenance Program (ROADMAP).
Project funding was provided by a National Estuary Program grant from the Washington State Department of Ecology.