As a part of Mile High Flood District’s criteria manual update, greater attention had been placed on receiving pervious areas (RPAs), which include vegetated swales and buffers, as well as other pervious surfaces that receive runoff from impervious areas. Since that update, stormwater industry leaders, local governments, and development engineers have encouraged integration of these types of features in practice. While there have been many successful projects implementing RPA for runoff reduction, there also have been challenges to implementation including:
- Difficulties of establishing RPAs with poor soil conditions.
- Restrictions on use of irrigated turf and difficulties of establishing RPAs with dense vegetation with limited or no irrigation.
- Concerns with long term inspection and maintenance or modifications by property owners.
- Methods for crediting use of RPAs in water quality and drainage calculations.
- Redistribution of concentrated flow.
This webinar will discuss approaches to planning and design of RPAs, methods for quantifying hydrologic benefits of RPA, and challenges with implementation. While this webinar will draw examples from Colorado, the fundamental concepts of how RPAs provide runoff reduction and many of the challenges discussed apply to many other regions.
Learning Objectives:
- Evaluate the role of receiving pervious areas (RPAs) in reducing stormwater runoff and improving water quality within site design and drainage systems.
- Apply planning and design strategies for RPAs, including approaches to soil limitations, vegetation establishment, and flow distribution from impervious surfaces.
- Analyze methods for quantifying hydrologic benefits and addressing implementation challenges such as maintenance, irrigation constraints, and regulatory crediting in stormwater calculations.
