North Central Texas Council of Governments Integrated Stormwater Management Program Water Quantity and Quality through Development, Design, and Construction Strategies

Challenge

The North Central Texas Council of Governments (NCTCOG) is a regional planning agency that assists local governments in planning for common needs, cooperating for mutual benefit, and coordinating for sound regional development. The NCTCOG region is made up of sixteen counties including the Dallas Fort Worth Metroplex, where growth and development present both opportunities and growing pains. With a membership of over 230 cities, counties, school districts, and special districts, a population of more than seven million, and no regulatory flood control district, communities in the region wanted guidance to help them achieve their water quality protection, streambank protection, and flood mitigation goals. The communities also needed resources to help them meet obligations for their state stormwater permits. 

Solution

The NCTCOG began collaborating with communities, developers, and engineering firms in 2002 to create the integrated Stormwater Management Program (iSWM™). This cooperative initiative created a regionally-developed comprehensive stormwater design manual and program that addresses water quality, streambank protection, and flood mitigation and conveyance through a system of development, design, and construction strategies. Low-impact development techniques are applied on a site-by-site basis to offset the impact of urbanism and fast-paced growth. 

The iSWM program provides benefits to local governments as well as residents, businesses, and property owners. iSWM designs emphasize open space and preserve natural features that create livable communities with character and access to nature. Designs based on the iSWM program let communities handle stormwater more effectively and with fewer flooding incidents impacting citizens, property values, and critical infrastructure. The program facilitates consistent stormwater approaches and outcomes across watershed jurisdictions by requiring developers to work with similar technical standards and methodology. The program also allows each city to customize to meet unique needs. Implementing iSWM may help a community achieve credits toward a lower FEMA Community Rating System rating. 

Image 1: Wall plaque describing the City of Denton as a Silver iSWM regional community
Image 1: Wall plaque describing the City of Denton as a Silver
iSWM regional community
Image 2: Street sign denoting community participation in the iSWM Program
Image 2: Street sign denoting community participation in the iSWM Program
Image 3: Razor Ranch Development, Bioretention Area with Sawtooth Curb, Denton, TX
Image 3: Razor Ranch Development, Bioretention Area with Sawtooth Curb, Denton, TX

Outcome/Results, Benefits, and Lessons Learned

Risk MAP Phases

  • Risk Awareness and Mitigation Outreach 
  • NFIP Map Changes and Impacts 
  • Resilience 

Risk MAP Goals Advanced

  • Advancing Action 
  • Identifying Action 
  • Increasing Awareness 

In 2014, the iSWM tiered measurement scoring system was released. Communities use their local ordinances to fill out a tiered measurement sheet with outcomes based on the iSWM Criteria Manual. Communities that go above and beyond implementing iSWM criteria are recognized for their efforts. The combination of partial or full application of policies determines whether a community achieves gold, silver, or bronze status. A panel made up of iSWM Implementation Subcommittee members review the applications. iSWM Certified Communities are acknowledged at their city council meetings and receive a wall plaque and street sign to commemorate their achievement. 

Designing infrastructure to fully developed watershed conditions, protecting against and reducing erosive velocities, and creating stream buffers and preserving open space are among the 22 outcomes included in the iSWM criteria. 

Other watershed programs at NCTCOG complement iSWM. NCTCOG staff are working with counties on an initiative with similar criteria, called the 16-County Watershed Initiative. The Regional Stormwater Management Coordinating Council and its task forces help communities meet their Municipal Separate Storm Sewer System permit (MS4) requirements. 

The Trinity Common Vision Program focuses on a portion of the Trinity River Corridor in the Dallas-Fort Worth Metroplex. The program, a partnership that includes participating communities, FEMA Region VI, and the U.S. Army Corps of Engineers, aims to ensure that there will be no increase in erosive velocities, no rise in flood elevation, and no decrease in flood storage capacity during floodplain development. 

Resources

NCTCOG Environment and Development

NCTCOG iSWM Website

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Last updated April 28, 2021