Arlington works to upgrade and maintain its stormwater infrastructure, reduce flood risks and help private property owners learn more about their flood risk.
When it rains, stormwater flows through Arlington's drainage system, which includes:
Through the course of development, more than half of Arlington's original streams were replaced by a system of underground storm sewer pipes. Rain water in the storm sewer system is discharged to Four Mile Run, other Arlington streams, or the Potomac River.
Most storm sewers in Arlington County are reinforced concrete, corrugated metal or terra cotta. Most of the collection system has been inspected over the past 12 years and is in good condition, with repairs, replacements and rehabilitation implemented as necessary. Reinforced concrete pipes typically have a life span of 75–100 years, and rehabilitation can increase the life span another 25–40 years. Corrugated metal and terra cotta pipes have a significantly shorter life span, and therefore, pipes made of these materials are being proactively replaced with pipes made of reinforced concrete.
As part of Flood Resilient Arlington, we are improving storm capacity in priority watersheds, informed by the Storm Sewer Capacity Study. See all stormwater and stream projects.
Inspecting and maintaining infrastructure is critical to ensuring it functions well. Outfall rehabilitation projects help repair infrastructure and stabilize steep slopes.
Reducing risk of flooding for public and private property. Learn more about reducing your risk of flooding
Know your flood risk. Is your property in a floodplain? Learn more about Flood Insurance Rate Maps and floodplains.