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.
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.