At its meeting on January 23, the joint Technical Advisory Committee (TAC) formed by the Capital Area Regional Planning Commission (CARPC) and the Dane County Lakes and Watershed Commission (LWC) introduced some draft policy recommendations for stormwater management regulations in Dane County. These recommendations are likely to impact the cost of stormwater controls for both new developments and redevelopment projects.

Stormwater regulations look at controlling both the rate and volume of stormwater runoff and focus on the difference between the runoff that would have occurred pre-development versus the amount of runoff that occurs after a site has been developed. Although current policies require 90 percent of that increased runoff volume to be controlled, CARPC and the LWC asked the TAC to evaluate the feasibility and benefits of a policy to control 100 percent of that increased volume to help reduce flooding during storm events. This would be more aggressive than current standards imposed by the Wisconsin Department of Natural Resources.

Draft recommendations of the TAC include:

• Revising county ordinances to most efficiently reduce runoff volume in future development projects by requiring 100 percent control of any runoff higher above the pre-development runoff.
• Redevelopment projects will be required to control at least 50 percent of the runoff over the pre-development volume.
• Not all controls would need to happen on-site - off-site controls could be through a county-controlled trading or fee-in-lieu program;
• Additional new requirements would apply to internally-drained areas, or those areas without any outlets for stormwater runoff to a lake or river.

In a draft example of how these new requirements could impact new developments, the TAC estimates this policy would increase the cost by about $935 for a typical new residential lot. The cost could be reduced to approximately $360 per lot if off-site controls or trading were used. However, off-site trading and a fee-in-lieu option will only be available if the county is able to develop that program.

See draft recommendations at link below.

https://danedocs.countyofdane.com/webdocs/PDF/capd/2017/StormwaterTAC/TAC_Report_PublicComment_Draft_020617.pdf