Unless managed properly, stormwater may carry pollutants to waterways as overland flow, or runoff, and also cause streams and rivers to overflow their banks.  Stormwater ordinances establish standards for directing, conveying, and storing stormwater flow so as to ensure that the water quality of receiving streams is improved or maintained and that flood hazards are adequately controlled.  


Adopting discharge standards and designing infrastructure for storms of specific sizes can help protect water quality and reduce flood risks. 


With climate change, the size or frequency of the design-level storms may change, resulting in the installation of undersized infrastructure.  It may also be more cost-effective to manage some of the stormwater on-site through green infrastructure than to design and install conventional off-site stormwater conveyancing and storage systems. 


Example 1: Ohio

Comprehensive Stormwater Management

Description: Model Stormwater Ordiance - Chagrin River Watershed Partners, Inc. 


Example 2: Michigan

Environmental Protection Options

Stormwater Management

Description: Management plans and other stormwater options for the state of Michigan.


Example 3: Lake County, Illinois

Stormwater Management

 Description: Watershed Development Ordinances


Example 4: Green Bay, WI

Green Bay Storm Water

Description: Storm water management plan for Green Bay.


Example 5: Manitowoc, WI

City of Manitowoc Storm Water

Description: Storm water codes for the City of Manitowoc.


Photo Credit: Lake County Illinois