Commonwealth, Ashby, Glebe Flood Mitigation Project

The Commonwealth Avenue, Ashby Street, Glebe Road Project will mitigate flooding by installing new, larger pipes.
Page updated on February 23, 2023 at 2:53 PM
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Overview

CAG Location map

The Commonwealth, Ashby, Glebe Flood Mitigation Project combined the top two large capacity projects will provide flood relief for the neighborhood near the intersections of Commonwealth Avenue and East Glebe Road, and Ashby Street and East Glebe Road. The proposed design includes new parallel relief sewers along Commonwealth Avenue and East Glebe Road, which will increase the capacity of the storm sewer system. Additionally, a new outfall will be installed to discharge flows to Four Mile Run. Finally, green infrastructure practices will be implemented to provide a water quality benefit to the watershed. 

• Status: In design
• Total Estimated Cost: $50,000,000
• Funding Source: Stormwater Utility, Community Flood Preparedness Fund (CFPF) grant 

Project Dashboard map

Capital Projects

Check the status of the City's flood mitigation projects using this interactive map tool.

Background

The City of Alexandria has experienced repeated and increasingly frequent flooding caused by climate change-induced storms near the intersections of Commonwealth Avenue near East Glebe Road, and East Glebe Road near Ashby Street. These increased flooding occurrences corroborate findings from the City of Alexandria’s Storm Sewer Capacity Analysis (CASSCA, 2016), which shows storm sewer networks along Commonwealth Avenue and East Glebe Road within the project area do not have adequate capacity to convey runoff from the intense storm events experienced in recent years. This increased flooding is attributed to old infrastructure, design criteria at the time of construction and climate change. 

Project stages

Planning

A project planning task was developed and awarded to the consulting firm Jacobs in early 2022. Planning tasks are the basis for the design stage of work and is conducted concurrently with the procurement of the design phase contractor. 

Planning tasks: 
• Data collection
• Modeling of existing conditions in the sewershed
• Development of high-performing alternatives to alleviate flooding

The City and the consultant identified a preferred alternative, which acts as the basis for the design stage of work. This work was performed concurrently with the procurement of the design phase contractor. 

Design

The design phase contract was advertised in early 2022 and awarded to Jacobs as the prime contractor in late 2022. Jacobs will lead a multi-discipline team for the duration of the design phase. The project will be developed in close collaboration with City staff and the community. After completion of the design, the project will be advertised for construction.

Design tasks: 
• Detailed site survey 
• Storm sewer modeling
• Development of construction drawings 
 

Construction

Construction is expected to start in 2026 and end by 2027.

On-Site: Photos from the project site

A visual look at progress on the Commonwealth, Ashby, Glebe Flood Mitigation Project. 

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A land surveyor contracted by the City uses a theodolite to measure angles on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
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A land surveyor contracted by the City uses a theodolite to measure angles on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
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A land surveyor contracted by the City plots points of infrastructure on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
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Staff from the City and Jacobs conducted a site walk on Nov. 15 in the neighborhoods of Commonwealth Avenue, Ashby Street and Glebe Road to understand how construction equipment will move in the area as they plan a large capacity flood mitigation project. (City of Alexandria)
11152022 DSC_1090
Staff from the City and Jacobs conducted a site walk on Nov. 15 in the neighborhoods of Commonwealth Avenue, Ashby Street and Glebe Road to understand how construction equipment will move in the area as they plan a large capacity flood mitigation project. (City of Alexandria)
11152022 DSC_1033
Jonathan Whiteleather, technical project manager, reviews a sewer map during a site visit to the neighborhood of Commonwealth Avenue, Ashby Street and Glebe Road on Nov. 15. (City of Alexandria)
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Grid View Close Modal
12132023 DSC_1485
A land surveyor contracted by the City uses a theodolite to measure angles on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
12132023 DSC_1487_01
A land surveyor contracted by the City uses a theodolite to measure angles on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
12132023 IMG_7383
A land surveyor contracted by the City plots points of infrastructure on Montrose Avenue. The data collected will be incorporated into the design of the Commonwealth, Ashby, Glebe Flood Mitigation project. (City of Alexandria)
11152022 DSC_1079
Staff from the City and Jacobs conducted a site walk on Nov. 15 in the neighborhoods of Commonwealth Avenue, Ashby Street and Glebe Road to understand how construction equipment will move in the area as they plan a large capacity flood mitigation project. (City of Alexandria)
11152022 DSC_1090
Staff from the City and Jacobs conducted a site walk on Nov. 15 in the neighborhoods of Commonwealth Avenue, Ashby Street and Glebe Road to understand how construction equipment will move in the area as they plan a large capacity flood mitigation project. (City of Alexandria)
11152022 DSC_1033
Jonathan Whiteleather, technical project manager, reviews a sewer map during a site visit to the neighborhood of Commonwealth Avenue, Ashby Street and Glebe Road on Nov. 15. (City of Alexandria)

News and Public Announcements

Project notices

• Surveyors from RDA will be implementing traffic control, including mobile lane closures, along Glebe Road from Commonwealth Avenue to past Montrose Avenue on Feb. 1. Drivers should heed flaggers and stop as directed. The process is expected to take eight hours.
• Nov. 15: Staff from the City and Jacobs conduct a site walk along Commonwealth Avenue, Ashby Street and Glebe Road. 

Community meetings

 

Contacts

For the community:
Jonathan Whiteleather, P.E. 
Technical Project Manager
703.399.9392
jonathan.whiteleather@alexandriava.gov

For the media: 
Camila Olivares
Senior Communications Officer, Department of Transportation & Environmental Services
703.541.9594
camila.olivares@alexandriava.gov