This is an ordinance to repeal the 1993 Storm Drainage Design Manual and replace it with an updated 2020 Stormwater Design Manual. The revisions to the manual were necessary to bring drainage criteria up to date, as well as technical standards, and improve the clarity and effectiveness of the stormwater development guidelines.
The 2020 Stormwater Design Manual is set to go into effect on January 18, 2021. All current design and construction projects that are already utilizing the 1993 Storm Drainage Design Manual will continue to use that manual through design and construction. Any engineering design projects and development site plans that start after the effective date will use the updated 2020 Stormwater Design Manual.
The 2020 Stormwater Design Manual revisions are bringing outdated criteria up to current standards and improving the effectiveness of the manual with improved processes and procedures during the design phase. Updates include, but are not limited to:
- Hydrologic and hydraulic design standards
- Review/permitting processes and forms
- Multiple figures, tables, and forms were revised or added (i.e. Variance Request Form, Downstream Assessment Checklist, Floodplain Development Permit)
- Latest regional and state practices, city standards and policies
- Stormwater management goals and objectives
The revisions to the design criteria and standards in the updated 2020 Stormwater Design Manual should have minimal impact to the design/construction community.