Hume Avenue Stormdrain Bypass project
Overview
The Hume Avenue Stormdrain Bypass project will provide flood mitigation for residential homes fronting Hume Ave. and E. Raymond Ave. The main work is to install an alternate storm sewer along Hume Avenue to bypass the existing pipe in the backyards of the townhomes on the south side of Hume Avenue. During design development, the City identified a need for new storm sewers and storm inlets along E. Raymond Ave. to capture flood waters earlier, before they can collect in low-lying areas.
Due to the significant amount of disturbance required to install these improvements, several additional capital improvements will be delivered with this project: The sanitary sewer on E. Raymond will be upgraded from an 8" dia. pipe to a 12" dia. pipe; Hume Ave. will be restored to achieve a 6" curb height; Hume Ave. will be re-surfaced to address existing patches and potholes within and adjacent to the project area; a check valve will be installed under the parking lot of Truist Bank at 2809 Mt. Vernon Ave.
• Status: In Design
• Total Cost: $4,440,000 ($670,000 in federal grant funding)
• Funding Source: Stormwater Utility, American Rescue Plan Act grant
Progress Update
The City completed review of the 90% design plans and issued comments in late February. Additional geotechnical investigation was required to locate subsurface gas lines within the work area.
A test pitting operation along Hume Avenue and East Raymond Avenue using a mechanized drilling rig was completed at the end of June. The City received test results in July, confirming the location of underground utility pipes at critical locations to ensure constructability of the City's proposed storm sewer upgrades. City staff met with utility providers to review the test results. A late revision to the project design was requested, which required additional coordination to resolve.
City staff will be meeting again with utility providers in August to resolve the comments. Final design is anticipated to be complete in September following a resolution to utility relocations and approval of temporary right-of-entry agreements to support construction.
Door hangers with additional test pitting information were distributed to residents prior to the operation.
Timeline
Investigation
The City of Alexandria's Storm Sewer Capacity Analysis (CASSCA) reviewed the performance of the City's storm sewer system at the watershed level and identified problem areas where conveyance or capture was unable to meet the demand of the City's design storm event. Throughout 2021 and early 2022, the City's Flood Action Alexandria team conducted field investigations to confirm the extent of issues identified by CASSCA and reported by residents via Alex311. The field investigation identified several upgrades to the storm sewer that could be implemented in advance of the Commonwealth, Ashby, and Glebe Large Capacity Project, which is currently under design.
Design procurement
The City Flood Action Alexandria team selected AECOM to provide design and construction oversight services for the Hume Ave. Stormdrain Bypass Project. A purchase order for design services was issued in June of 2022.
Design
In August of 2022, the City began design on the Hume Ave. Stormdrain Bypass Project. Design was broken into multiple phases, including data collection, alternatives assessment, 30% schematic plans, 60% design plans, and Final Construction Drawings. The consultant will also provide technical construction specifications, a basis of design report, and a cost estimate for the proposed design. The project design goals are listed below:
- Reduce flooding in your neighborhood through the installation of new pipes and inlets
- Mitigate flood impacts that do occur by containing flooding within the roadway when possible
- Assess the performance of the system under the City’s Standard Design Storm (10-Year)
- Re-locate the storm sewer between Hume and E. Raymond Ave. to the roadway to facilitate future maintenance
- Minimize construction disturbance to residents by implementing sanitary sewer improvements and street paving with storm sewer work
- Ensure that upstream improvements do not adversely impact downstream properties
On-Site: Photos from the Hume Avenue Bypass project
News and Public Announcements
Project notices
• Nov. 2: Portions of Hume Avenue will be closed so crews can conduct geotechnical boring work.
Community meetings
• Aug. 24, 2022: On-site public kickoff meeting hosted by Flood Action Alexandria team with residents
• Dec. 15, 2021: Virtual meeting with residents hosted by Flood Action Alexandria team
• November 2020: On-site community meeting with residents
Contact
For the community:
Mitch Dillon, P.E. (He/Him)
Associate Technical Project Manager
703.746.4028
mitch.dillon@alexandriava.gov