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

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Vault-time-lapse.jpg The proposed stormwater vault at the new elementary school at the Cardinal ES site is a community-driven project following the devastating losses and impacts to surrounding businesses and homes from the July, 2019 storm event.

This 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.

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 a much larger detention vault 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 Rd, Arlington, VA 22205.

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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 includes the stormwater detention vaults.  Construction began in December, 2021 and should take about 12 months.  The school playground will remain open and available throughout construction, but the large athletic field that operates as an extended playground will be closed during construction of Phase 2.  Phase 2 is a consult level engagement project. 

Construction Schedule(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.








Engagement Process

Date Event Materials
 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