Approved by the Energy, Environment, and Water Policy Committee On February 20, 2024 
Approved by the Public Policy and Practice Committee on June 5, 2024
Adopted by the Board of Direction on July 18, 2024

Policy

The American Society of Civil Engineers (ASCE) supports the management of stormwater runoff to reduce water pollution, prevent flooding, and to use it as a water source rather than a waste product. ASCE encourages:

  • Coordinated and streamlined federal, state, and local regulatory programs.
  • Recognition that stormwater management requires coordination at the watershed level – which often cross political boundaries - and require flexibility to reflect site-specific and regional conditions.
  • Updated and adapted technical guidance incorporating increased frequency and magnitude of precipitation and runoff due to climate change.
  • Technologies and policies that encourage the collection of stormwater runoff to augment potable and non-potable water sources during periods of drought.
  • Use of Low Impact Development, Green Infrastructure approaches, and Nature-based Solutions to stormwater management.
  • Regulatory approaches that focus on meeting receiving water quality standards utilizing best management practices.
  • Asset management approaches to stormwater utilities include inspections, operations, and maintenance, and incorporate life-cycle cost evaluations.
  • Funding for research and implementation of sustainable, cost-effective approaches to stormwater management. 
  • Consideration of social equity for disadvantaged communities in at-risk areas.

Issue

Storm intensity and duration combined with urbanization and other land use changes lead to increased stormwater runoff quantity, decreased infiltration to groundwater, and non-point source pollution transported to our waterways. Water quality concerns include fertilizers, nutrients, metals, wastewater leaks, and increased temperature. Increased stormwater runoff quantity can lead to flooding, loss of property, erosion, reduction in base-flow, loss of aquatic habitat, increased water velocity in streams and rivers causing increased turbidity, and contamination of recreational waterways and drinking water supplies. Additionally, our nation’s stormwater infrastructure – are increasingly inadequate due to age, lack of maintenance, and increased storm size and frequency.

Rationale

Low-income areas are often exposed to both the highest flood risk and the greatest environmental hazards but are the most limited in terms of capacity to adapt to extreme weather events and chronic stresses due to repeated flooding from frequent, smaller storms. The combined effects of infrastructure aging, growth in urbanization, and increases in precipitation extremes heightens the importance of stormwater management in civil infrastructure planning, not only to control the negative impacts of runoff, but also to protect public health and to capture stormwater runoff as a water supply resource. It is important for policy makers to understand that increased risk and aging and degrading assets will need both financial and policy initiatives to protect health, safety, welfare, and the environment. 

This policy has worldwide application
ASCE Policy Statement 441
First Approved in 1995