Stormwater Management

Stormwater Defined


Stormwater is generated from rain and melting snow which is conveyed over impervious surfaces such as rooftops, streets and sidewalks. Rather than being absorbed into the ground, much of the stormwater in urban or suburban areas flows over impervious surfaces into roof drains or catch basins in the streets and from there into the storm sewer. This stormwater then discharges, untreated, into our local waterways and, ultimately, the Chesapeake Bay. Impervious surfaces generate a significant amount of stormwater which can pose challenges to the City by contributing to sewer overflows, washing pollutants into our waters through the municipal separate storm sewer system (MS4), and causing flooding.

What Can We Do About Stormwater?



In compliance with State and Federal Regulations, the City of Portsmouth operates a Stormwater Management Program to help improve the quality, and reduce the quantity, of stormwater runoff.

Program activities include construction of water control structures, ditch and pipe maintenance, water quality monitoring and testing, lake and pond management, enforcement of related City ordinances and program standards, and public education. 

Statistics



Portsmouth’s Stormwater System is comprised of:
  • Total street length - 513 miles
  • Street length with roadside ditches or other - 88 miles
  • Street length with curb and gutter - 247 miles
  • Total drainage pipe length - 268 miles
  • Length of pipe smaller than 15” in diameter - 23 miles
  • Length of open ditches - 101 miles
  • Length of roadside ditches - 87 miles
  • Drainage structures - 15,658
  • Outfalls that discharge to area waterways and, ultimately, the Chesapeake Bay - 611
  • City-owned structural BMPs, i.e., lakes, ponds, bioretention basins, etc.
Clean Water Act

Mission



The mission of the City of Portsmouth's stormwater management program is to safely and efficiently control runoff; protect public health and safety; protect property; minimize the discharge of pollutants to receiving waters; guide development; and protect and enhance water quality in creeks and stormwater lakes in the community. The City's program will provide for construction, operation, maintenance and management of stormwater controls and will complement and support other City programs. The program shall include regulatory compliance, organized operations, sensible and adequate financial stability, and public education and outreach.

Commonwealth of Virginia Regulations



The City of Portsmouth is currently regulated under a Municipal Separate Storm Sewer System (MS4) Permit, #VA0088668, administered by the Commonwealth of Virginia. Under this permit, the City must implement a series of programs to reduce the discharge of pollutants from the MS4 in a manner that protects the water quality of nearby waterways. Learn more about these program requirements on the “MS4 Permit” page.