Overview
The goal of the Hooffs Run Culvert Bypass Project is to provide flood relief for neighbors, homeowners, and businesses along the existing Hooffs Run and Timber Branch culverts, without making flooding conditions worse elsewhere in the city.
The existing culverts are large concrete pipes, multiple feet wide and high, which carry streams (Hooffs Run and Timber Branch). These streams have historically flooded, and flooding continues to worsen as climate change brings more frequent and more intense rainfall events. As a result, the existing culverts are not large enough to handle all the stormwater flow during large rain events.
The City is currently modeling and evaluating concept-level alternatives to reduce flooding, including stormwater storage options and a new, parallel large-capacity stormwater pipe under Russell Road.
• Status: In design
• Total Estimated Cost: $60,000,000
• Primary Funding Source: Stormwater Utility Fee
Background
Did you know the City has many streams flowing through it that you may not be able to see? For a history of Hooffs Run and other waterways in the City of Alexandria, check out the Flood Action Story Map (History’s Impact tab).
Hooffs Run: 1920 to 1950
Hooffs Run was mostly channelized by the 1930s to improve sanitation. Some of the stream segments were piped and covered by asphalt, green space, or concrete. The large pipes that contain streams are called culverts. The image below from 1949 shows where the stream was put into culverts.
Historic Flooding
Due to the alterations of the channel and increased impervious area, flooding is not a new issue in the Hooffs Run Watershed. For instance, in 1922, “the worst rainstorm in 44 years” caused widespread flooding in the Washington, D.C., area, including the North Rosemont neighborhood of Alexandria.
Source: Washington Times, September 3, 1922
Hooffs Run Today
The streams continue to be piped in culverts but are visible in some locations. You can see what the culverts look like below.
As our climate continues to change, storms are getting more frequent and more intense. Rain falls faster and in greater quantities, overwhelming the pipes that carry the streams. This causes flooding of streets and properties along the culverts. The City is designing solutions to reduce flooding along the existing Hooffs Run and Timber Branch culverts. The City is considering alternatives and vetting multiple options using models and engineering feasibility analysis.
Project Stages
Planning
In 2016, the City conducted the City of Alexandria’s Storm Sewer Capacity Analysis (CASSCA, 2016). Preliminary solutions were presented in the analysis but require updates based on more recent climate and infrastructure data.
Design
The design phase contract was advertised in 2022 and awarded to Arcadis as the prime contractor in mid- 2023. Arcadis will lead a multi-discipline team for the duration of the design phase. The design phase consists of two parts –concept design and advanced design– and is expected to be completed near the end of 2025.
Concept design includes:
• Data collection, site survey of existing conditions (i.e. topography, utilities, roadway features)
• Updated modeling of existing pipes and flooding conditions
• Development and evaluation of high-performing alternatives to alleviate flooding
• Coordination with other city and state stakeholders, like AlexRenew and Virginia Passenger Rail Authority, who also are also conducting projects in the same area.
The City and Arcadis will identify a preferred alternative to present to the public and other stakeholders.
Advanced design includes:
• Detailed calculations and modeling of the preferred alternative
• Detailed design, including design of stormwater management solutions and site restoration
• Construction planning including traffic maintenance and erosion and sediment control
• Development of construction bid documents for a contractor to bid on
• Permitting and funding allocation
The project will be developed in close collaboration with City staff and with input from the community.
Construction
Construction is expected to start in 2026 and end by 2028.
On-site: Photos from the Project Site
A look at the Hooffs Run Culvert Bypass Project
Coordination of Projects Near King Street
Multiple agencies including the City of Alexandria, AlexRenew, and Virginia Passenger Rail Authority (VPRA) have projects near the intersection of King Street and Commonwealth Avenue. The City is actively working and coordinating with the owners of these projects to ensure the projects integrate with each other and consider overall construction impacts to the community. We understand that construction impacts can be frustrating. When complete, these projects will collectively serve to make the City stronger and more resilient.
Resources
Meetings and Materials
Staff from the City of Alexandria, Virginia Passenger Rail Authority (VRPA) and Virginia Railway Express (VRE) shared information and answered questions from the public on ongoing and upcoming infrastructure projects during an October 4 open house.
Public Open House: October 4, 2023
The City of Alexandria and its regional partners, Virginia Passenger Rail Authority (VRPA) and Virginia Railway Express (VRE) hosted an open house to share information on ongoing and upcoming infrastructure projects slated for the King Street and Commonwealth Avenue Corridors.
The projects include:
- Hooffs Run Culvert Bypass (flood management)
- Fourth Track Project (rail capacity improvement)
- King and Commonwealth Rail Bridges (rail bridge replacement)
- VRE Station Improvements (rail station improvements)
- King and Commonwealth Streetscape Improvements (Safety and mobility improvements)
Stay Connected
Sign up for eNews Updates
Sign up for the City of Alexandria's eNews alerts to receive information about project updates, upcoming meetings and events, and community news. Select "Flood Action Alexandria" under "Transportation and Environmental Services" when choosing your subscription.
Contact
Laura Bendernagel, P.E.
Technical Project Manager
845.661.1340
laura.bendernagel@alexandriava.gov