Cardinal Elementary School Stormwater Vault


Cardinal School site near the Westover shopping district in the Torreyson Run watershed, 1644 N McKinley Rd, Arlington, VA 22205  View Map

Google Map



Projects to Watch Video - Cardinal Elementary School Detention Vault

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

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.  


Cardinal School site near the Westover shopping district in the Torreyson Run watershed, 1644 N. McKinley Road, Arlington, VA 22205.

View Map


Phase 1 of the project consisted of installing underground pipe and junction boxes to divert water from an existing storm sewer pipe that runs underneath the school parcel to the vault (these areas are shown in red on image at top right of the page). Phase 1 is complete. Phase 1 was a communicate level engagement project.

Phase 2 included construction of the stormwater detention vaults.  The vault construction began in December, 2021 and reached substantial completion in June, 2023.  Sod has been installed on the athletic fields and they will be available for community use in Fall, 2023.  Phase 2 is a consult level engagement project. 

The additional storm sewer project to add a new storm sewer pipe on N. Lexington St. has also been completed. 

Construction Updates(PDF, 111KB) 

Vault Construction Updates

January, 2022 - The contractor will begin setting up the Maintenance of Traffic (MOT) around the site, including the closure of part of one lane on Lexington St. Neighbors may see some excavators working on-site to do some initial grading and to create access roads on the site.  The dewatering contractor will begin work in early January (to remove water from the construction area), and that work will take about 3 weeks. 

February, 2022 - One of the first steps in the stormwater vault construction is the installation of support structures for the area that will be excavated.  The initial phase is anticipated to begin in February for the larger vault with both driving and drilling piles in the ground.  This work will last 4-6 weeks. This work will result in a fair amount of noise on site and construction will continue to take place within the County mandated work hours.

March, 2022 -  The contractor will complete the pile driving in late March.  Excavation will also continue on vault #1. 

April, 2022 -   The contractor will continue excavating Vault #1. The contractor has placed a gravel layer on the bottom of the vault excavation in preparation for the placement of the concrete vault modules.   The pre-cast concrete modules were initially scheduled to arrive in mid-April, but will now start arriving in May.

May, 2022 - The first concrete modules arrived on site on May 10th.  The contractor will use the concrete modules to assemble the stormwater vault as they arrive on site. 

June, 2022 - Delivery of concrete modules will continue.   The contractor will continue assembling the larger stormwater vault. 

July, 2022 - Delivery of concrete modules will continue.   The contractor will continue assembling the larger stormwater vault. 

August, 2022 - Delivery of concrete modules will continue.   The contractor is nearing completion of construction of the larger stormwater vault, and has started backfilling soil on top of the larger vault. 

September, 2022 - The contractor continue assembly and backfilling of the larger stormwater vault. 

October, 2022 - The contractor will complete construction and backfilling of the larger stormwater vault.  The contractor will begin excavating the area for the smaller stormwater vault and may begin placing some modules for the smaller vault. 

November, 2022 - The contractor has excavated the area for the smaller vault and has started placing the vault modules.  The smaller vault should be complete by late November/early December.

December. 2022 - The smaller vault is complete.  The contractor will be completing the vault connections to adjacent storm pipes and covering the vault with soil.

January, 2023 -  The contractor is completing the final grading for the site and will be installing a stormwater filtration device where water flows into the vault.  The contractor will change the Maintenance of Traffic (MOT) controls on N. Lexington St, and removing some of the concrete barriers to reopen portions of both lanes for traffic.  There will still be an area around the site construction entrance that will be closed to traffic as the contractor completes the final tasks at the site.   There will be sufficient space for two way traffic to travel by the construction entrance. Although the jersey barricades will be removed, we continue to urge drivers to avoid the area, if possible, and to exercise caution when driving past the construction site. 

February, 2023 - Washington Gas is re-locating a gas line on N. Lexington St.  This work should take 3-4 weeks.  This work is in preparation for a short term project to install a new stormwater pipe on N. Lexington St. 

March, 2023 -  The vault contractor will be installing top soil and sod to restore the athletic fields above the vaults.  A new section of storm sewer pipe will be installed on N. Lexington St. to direct water into the new storm sewer vault.  This work will begin in mid-March and will finish in May.  

April, 2023

The contractor will remove the barriers within the storm system to make the vaults operational during the first week of April.  The contractor will  continue to place sod on the athletic field and complete other site restoration activities.

A separate project is underway to install a new segment of stormwater pipe on N Lexington St, between 18th Rd N & 18th St N.   This work will begin near the intersection of N Lexington St & 18th Rd N and will progress southward along N Lexington St. N. Lexington St is closed to through traffic for safety reasons because of the depth of the excavation for the pipe.  Local vehicular traffic and pedestrian access to the eastern sidewalk will be allowed at all times. 

May, 2023

The contractor has completed the installation of the new storm pipe in N. Lexington St and connected the new pipe to the vault.   The final step for this project will take place in the intersection of N. Lexington St and 18th St.  The contractor will be moving a section of sanitary sewer pipe that is in the way of the new storm pipe, and connecting the new storm pipe to the existing storm sewer on 18th St.   

This work will take place on 5/24-5/26 and 5/30-6/7.  N. Lexington St. between 18th St and 18th Road will be closed to through traffic for those dates. Local traffic will be allowed at all times.  Flaggers will direct traffic through the intersection of N. Lexington and 18th St. 

June, 2023

The vault project reached substantial completion on June 5th. The athletic fields will remain fenced and closed to public use over the summer to allow the sod to become well established.  The fields will be available for use in the fall.

N. Lexington St between 18th Road and 18th St will be re-paved in August.  


















Engagement Process

Date Event Materials
 March 1, 2023, 7 PM Lexington St Storm Pipe Project - Community Meeting 

Meeting Presentation(PDF, 3MB)

Meeting video

 June 8, 2022, 7 PM

 Construction Update Community Meeting  

Meeting presentation(PDF, 7MB)

February 23, 2022, 7 PM

Construction Update meeting

Meeting Presentation(PDF, 3MB)

Q&A Summary(PDF, 85KB)

 November 10, 2021 Cardinal School PTA meeting - transportation update  Meeting presentation(PDF, 2MB)
 September 22, 7-8 PM  Pre-Construction Meeting   Meeting presentation(PDF, 2MB)
July 28, 2021, 7 - 8 PM 90% Design Public Meeting Meeting presentation(PDF, 3MB)
May 26, 2021, 6:30 PM 65% Design Public Meeting Meeting presentation
March 2, 2021 Use Permit Public Meeting  
February 25, 2021 Sports Commission Meeting video
February 4, 2021 Leeway Overlee Civic Association Presentation
January 12, 2021 McKinley Elementary PTA Meeting Presentation
January 6, 2021 Highland Park Overlee Knolls Civic Association Presentation
January 5, 2021 Tara Leeway Civic Association Presentation
December 16, 2020 Meeting with McKinley PTA Board
December, 2020 School Board and County Board Meetings

APS Presentation

County Presentation

November 20, 2020 Four Civic Association (4CA) Virtual Meeting/Call
November 16, 2020 Civic Federation Stormwater Committee Virtual Meeting
October 23, 2020 Civic Federation General Meeting Meeting summary
July 6, 2020 Torreyson Run/Spout Run Civic Association Meeting
June 24, 2020 Four Civic Association (4CA) Virtual Meeting/Call
June 18, 2020 Torreyson Run/Four Civic Association (4CA) Meeting