As cities grow and expand, we hear the word redevelopment tossed around more frequently. But what is redevelopment? In its most simplistic definition, redevelopment is the action or process of developing something again or differently. How that applies to the civil site world is any new construction on a site that has pre-existing uses.

Redevelopment represents a process of land development uses to revitalize the physical, economic and social fabric of urban space, and there are a wide range of redevelopment projects.  Some redevelopment projects simply aim to renovate and rejuvenate an existing structure and lot. Others involve a complete demolition and rebuild.

How Does Redevelopment Impact Stormwater Design Approaches?

Stormwater regulations vary state to state, even county to county, but in most situations, there are different design requirements for new development vs. redevelopment projects.  Typically, redevelopment projects allow some sort of credit or variance from standard stormwater regulations. Redevelopment projects may result in a smaller stormwater management system compared to a new development of the same size.

For example, in Ohio, with no new impervious area added, redevelopment projects required 20% of the Water Quality Volume to be treated vs 100% for new developments. In most West Michigan communities, redevelopment standards require only the stormwater runoff associated with proposed impervious area needs to be treated vs new developments where 100% of the Water Quality Volume must be treated.

Redevelopment Stormwater Design Considerations

On a redevelopment project that is not adding any new impervious area, you may be allowed to design for a reduced water quality or quantity value. This could result in a smaller underground detention system and water quality device.

If any new impervious area is being added, say an expanded parking lot, you may be required to treat that new impervious area in full while combining that with the otherwise reduced existing site. While you would benefit from a reduced stormwater management system, you would still have to consider the ‘new’ development requirement for the added impervious area.

At the end of the day, it is always encouraged to reach out to your local reviewer to see what they classify as redevelopment and how that classification impacts your stormwater management system.

Benefits of Redevelopment

Redevelopment can revitalize a community socially and economically while benefiting the environment in the reuse of developed land. In addition, it allows for the protection of undeveloped lands and maintaining the natural environment and local ecosystems. In urban environments, redevelopment helps reduce the amount of vacant land in a city, revitalizing communities and having positive socio-economic impacts. Preservation of historic areas and structures can also be accomplished through redevelopment.