Cardinal Elementary School Stormwater Vault

How is the Cardinal Vault performing?  In total, since the vault was constructed, it has been activated 66 times. The highest water level recorded inside the vault occurred on June 13, 2025, reaching 45 inches during a 2-year storm event.

The Stormwater Vault at Cardinal Elementary School was chosen as the 2024 Virginia Flood Mitigation Project of the Year

Projects to Watch Video - Cardinal Elementary School Detention Vault

The stormwater vault at the Cardinal Elementary School was a community-driven project following the devastating losses and impacts to surrounding businesses and homes from the July 2019 storm event.

The project is an important step towards the goal of building a Flood Resilient Arlington. It is an effort to strategically use public land for multi-purpose goals to overcome space constraints and expand the capacity of the stormwater management system. The vault system is designed to hold just over 4 million gallons of stormwater.  The drainage area for the vaults is 222 acres.

A smaller stormwater detention tank was already included in the approved plans for the school project for temporary storage of stormwater following rain events. In response to community appeals, the County collaborated with Arlington Public Schools to design and build much larger detention vaults under the athletic fields that will form a cornerstone to a watershed-scale solution to reduce flood risk in the Torreyson Run watershed.