Alexandria Commonwealth Ash Flood Mitigation Community Meeting #5 - June 8, 2026
Alexandria Commonwealth Ash Flood Mitigation Community Meeting #5 - June 8, 2026
This was the fifth community meeting for the Commonwealth Ash People Flood Mitigation Project. Project Manager John Whiteher presented an overview of the project's progress, moving from design toward construction. The presentation covered updated traffic impacts, utility relocations, tree impacts, and risk management measures including geotechnical monitoring and pre-construction property condition assessments. The meeting included a question-and-answer session with residents.
Discussion Items
- Project Purpose and Solution: The project addresses frequent flooding at Commonwealth & Glebe and Ashby & Glebe due to an undersized storm sewer system. The solution involves adding a much larger box culvert, quadrupling the cross-sectional area of the outfall to Four Mile Run. Construction is expected to start in summer 2027 and last approximately 3.5 years: two years for storm sewer construction on Commonwealth, one year on Glebe, and six months on Montrose.
- Traffic and Access Impacts: All roads will remain open to emergency vehicles. Pedestrian and school/business access will be maintained. Parking lanes and bike lanes will be closed during active phases. Sidewalk closures will occur in specific areas, with detours clearly marked. The softball field north of Frankman Field will be used as a staging area. The Four Mile Run trail will have a temporary detour during outfall construction.
- Utility Relocations: Utility relocations are underway by the utility owners. Virginia American Water is currently relocating water lines, with Washington Gas and Verizon to follow. Coordination is ongoing with multiple utility companies to clear the path for the new culvert.
- Tree Impacts: Some trees must be removed due to conflicts with the storm sewer or utility relocations. Efforts were made to preserve large trees (e.g., two in front of Auburn Village by bending the culvert). At the outfall, invasive trees will be removed. Small recently planted trees east of Commonwealth will be replaced with native shrubs better suited to the poor soil. Median trees will be replaced with green infrastructure (bioswales) featuring narrow native trees, grasses, and perennials. Only about three trees on Ashby Street will be removed; the narrow buffer strip prevents replanting there. Residents will be notified in advance of any tree removals fronting their properties.
- Risk Management During Construction: Geotechnical monitoring will include vibration and movement sensors. Vibration monitors placed within 100 feet of active construction will trigger a work stoppage if thresholds are exceeded. Movement sensors on structures, pavement, and utilities (every 60 feet or denser) will detect settlement. Pre-construction property condition assessments will be offered voluntarily to properties within 100 feet of excavation (approximately 200 properties, including Auburn Village). The contractor will schedule assessments; police escort will be provided for interior surveys. Photos will document existing cracks or settlement to establish a baseline for any future claims. Claims would go through the contractor's insurance.
Public Comments & Testimony
- A resident asked for clarification on tree replanting on Ashby Street. Whiteher confirmed only about three trees are affected and the buffer strip is too narrow for replanting.
- A resident (from Wilson and Glebe) asked about water line relocation sequencing on Glebe and whether the sidewalk north of Glebe would be retained. Whiteher explained that the culvert will go under the sidewalk west of Wilson, but east of Wilson the culvert bends south, so sidewalk impacts are minor. Power lines (overhead and underground) were discussed; underground lines will be identified during final surveys.
- A resident representing Northside 10 expressed concern about delivery access. Whiteher stated that at least one of the two large eastern entrances will be maintained, and they will explore adding a temporary access point on Wilson.
- A resident asked for more detail on the median green infrastructure. Whiteher described it as a bioswale: a flat-bottom ditch with permeable media, an underdrain pipe connecting to the culvert, and smaller trees, grasses, and perennials. It is not designed for walking across.
Key Outcomes
- The project is on schedule for storm sewer construction to begin in summer 2027, pending completion of utility relocations and contractor procurement.
- Utility relocations (water, gas, fiber) are progressing; Virginia American Water is expected to finish water work by summer 2026.
- Pre-construction property assessment letters will be sent via certified mail (three attempts) to eligible residents. The city will also conduct outreach to ensure awareness.
- Tree removal notifications will be sent to affected residents closer to construction.
- Meeting slides will be posted on the city web page. Residents were encouraged to review prior meeting materials for detailed traffic impact plans.
- Continued coordination with businesses (e.g., Northside 10) and the Auburn Village homeowners association will occur.
Meeting Transcript
Good evening, everybody. My name is John Whiteher. I'm the project manager for the Commonwealth Ash People Flood Mitigation Project. This is community meeting number five. So tonight we're gonna go through uh an overview of the project. We'll walk through some high-level traffic impacts and mitigation measures. Uh, we'll talk through our utility relocations, uh the tree impacts of the project, and then we'll um move towards some of our risk management during construction, um, which includes geotechnical monitoring, uh pre-construction conditions assessments, um, and then we'll go through any questions uh at the end of the presentation. So um we'll start off with an update of where we've you know progressed since last meeting. Um so we're really moving from that design stage towards construction. Um since last meeting, we've received final design plans. Um we have utility relocation work underway. Um we continue coordinating with um other utility owners who are who are gonna follow uh currently Virginia American Water is out there, and then we have uh Washington Gas following and Verizon and some other telecom companies. Uh so we continue that coordination and continue coordination with schools, businesses, and other key stakeholders. Um we're currently targeting summer 2027 uh for the major stormwater construction. Um and again, that follows our pre-construction phase of getting all the utilities relocated. Um and then as we progress towards construction, the uh phasing access and traffic plans will begin to be more refined as we get a contractor on board. Um so just kind of going through you know, high-level reminder of the purpose and and solution of the project. Um the problem is frequent flooding in the project area. Uh two main areas at Commonwealth and Glebe and Ashby and Glebe experience uh increasingly frequent flooding in the project area. Um basically the storm sewer is too small to handle the uh the runoff draining to it. Um so other contributing factors, this is old infrastructure. Uh the design criteria at the time of construction is not up to current standards. And we are starting to observe increasingly intense and frequent rainfall. Um, so this is just a schematic showing um basically what happens during a flooding event. So the downstream pipe basically starts to fill up as water drains to the system, and water cannot enter into the inlets because the pipes are full, and those inlets start pushing out water and starts to surcharge and flood the area. So that's the problem. And then for our solution, basically what we're doing is just increasing the capacity of the existing system. So in this schematic, we we take that existing pipe and we add in a much larger pipe to get that water out of the low point and basically allow water to enter back into the system. Um these drawings at the bottom are just kind of giving a rough order of magnitude of how much capacity we're adding into the system. Um, so these three elliptical pipes represent the existing outfall. Um, and this these two boxes are basically what we're adding at at the new outfall. Um, and that gives us about quadruple the cross-sectional area, which correlates to the capacity. So it's it's a a lot of additional capacity, which just kind of shows you know how undersized the existing system was. Um, so what is being built? Um, so the this drawing here just shows a schematic of what the culvert's gonna look like during construction. Um, so we're gonna excavate a trench and put that you know, box culprit in the ground. Um during construction, you'll see these sheeting and shoring systems. We have a very tight area to work with. So that basically just protects our trench and protects the crews working. Um the second picture shows uh the new outfall to four mile run. So this is similar. Um what it will look like. Our outfall will have a debris rack to protect debris from entering in and clogging the system. And then we also are proposing green infrastructure, which adds a water quality benefit. And this will be along the existing PDNs of Commonwealth. Sorry, June, just look, we'll put a process here. Are these slides available online? I'll post these after the meeting. Yep. Great, great.
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