Roadside ditches can help manage the flow and quality of stormwater and play an important role in clean water. These resources for maintenance and planning can make these simple, common features an important contributor to clean water.
The Ditch Maintenance project includes:
- Refinement of ditch maintenance standards and enlarging the ditch maintenance toolbox
- Assessment of the characteristics and condition of several of King County’s roadside ditches
- A literature review on background data.
King County, with members of the Regional Operations and Maintenance Program (ROADMAP) and Herrera Environmental Consultants and used the information from the field evaluation, literature review, and input from ROADMAP members to develop a ditch maintenance matrix, field guide, and fact sheets to improve maintenance, operations, and design.
For field staff performing ditch maintenance:
- Considerations for Field Evaluation of Roadside Ditches
- Ditch Cleaning Strategies
- Maintaining Ditches that Convey Natural Flow
For administrative or office staff overseeing and providing direction for stormwater operations, maintenance, and/or stormwater capital projects:
- Ditch Mapping Recommendations
- Prioritizing Ditches for Inspection and Maintenance
- Permit Requirements for Ditch Maintenance
- Source Control Strategies for Ditches
- Ditch Retrofit Strategies
The project team also prepared a set of GIS and field data collection tools to support a roadside ditch inventory and assessment. These tools include:
- Guide to Roadside Ditch Inventory and Assessment Tools Technical Memorandum
- Geodatabase framework to facilitate desktop GIS evaluation of ditch significance
- Survey123 field form template to facilitate collecting data on ditch condition in the field
- ArcGIS toolbox for processing the desktop ditch significance and field evaluation ditch condition data to produce cumulative scores and assign maintenance priorities