The meeting consisted of a daytime work session (beginning at 10:15 AM) featuring presentations on a flood resiliency study and a public safety update, followed by an evening regular session (reconvened at approximately 7:10 PM) that included public hearings, ordinances, resolutions, and public comments.
Town in the middle and at the south end of the study area, Fort Smith Boulevard, near the shipyard. George Russian Highway was broken into Frederick Boulevard and Hanbury Abbas as sort of two different distinct solution areas, and Frederick Boulevard, we broke down into four different solution areas. Victory just uh where across I-264 was the main problem area on Vickering, but obviously that prevents access to the interstate, which is also a goal of this is to be able to move people from the downtown area to higher ground more efficiently. That's another goal of the study. Next slide. And so I'll step through the solutions that we have for Effingham, and then JD will address Portsmouth Boulevard. And so really tonight we're presenting these are examples, these are solutions that we have for these corridors. We also have solutions that JD just showed for the other corridors as well. So it's just to give a flavor of what the potential solutions look like when you're raising roads, dealing with either combined flooding down at right at the riverfront versus flooding upstream where you're dealing with mostly pluvial rainfall events, flooding the surface, and trying to get that either store locally or get it out efficiently and effectively. So here what we're seeing starting up at uh the north end of the Naval Hospital. What you're seeing on the left again are the same maps that we've been showing, where purple is 18 inches of uh flood depth for three feet of sea level rise and a 10-year rainfall event. You can see Effingham Street there is flooded, uh, it goes into the park and down to the river. Um, yellow again is three inches of uh flooding locally, um, so you can get a sense of what that range is. And then you can see on the right the potential solutions that we're trying to layer together to create something that allows for effective passage on Effingham during an event like this. And so that means raising the road, like JD was saying. Um so we're getting here up to six feet from two and a half, but once you raise the road, in order to allow the water that's upstream to continue to get out and not have any repercussions around it, that means you have to upgrade the the surrounding conveyance system. And so that's the roughly 2,000 linear feet of upsizing those pipes. But once you're you're upsizing the pipes, you want to make sure that the tide's not flowing in with three feet of sea level rise, and so adding tide gates at the downstream end on the river to make sure that it's not backing up into the system and reducing your capacity and your ability to get the rainwater out. And so, in conjunction with that, typically we'd have a pump station next to a stormwater basin or some other local storage to be able to have some capacity. So if you have larger more rainfall than you expect, you have a place for that to pool, and then you can get it out effectively. Um, in this case, like JD was mentioning the constraints. Uh so we have a super fun site here on the park, so we're not able to put in that stormwater detention basin. But instead, we can have the pump, we can pump the groundwater that's in the stormwater conveyance system out preemptively, and then you're able to continue to pump that system dry so that during these 10-year and three-foot sea level rise events, you're able to get the water out and have that safe passage to the hot to the hospital. Next slide, please. As we move down, here we're looking at Old Town. Again, it's the same panels, it'll be the same on the next slide, and the one after that. Uh purple is 18 inches of sea level of flooding, yellow is three inches of flooding. So you can see where it's flooding the most. Really, we're trying to address flooding on Effingham to provide that safe passage up to the hospital and down to the shipyard. And so we're raising the road again to get up to above that water level elevation. So we're getting up to six feet. That means just like we saw next to the hospital, increasing the sizing of the piping. So in this case, it's roughly 8,000 linear feet of pipes to try and get that water out, and adding in a tide gate at the downstream end so that you're not having the tide flow back upstream into the conveyance system. And just like next to the hospital, putting in a pump station to make sure that we're able to draw that down preemptively so that you're not dealing with a situation of combined flooding within the conveyance system due to the groundwater that's just taking up capacity, then you could preemptively get it out before the storm would pass. Next slide, please. And so, as we move down to the south, here we're calling it the south area, the south end of Effingham. Um here we're dealing, we're farther away from the river, so we're not dealing with the combined flooding as much. We're still talking about tide gates because there are regions to the east where we can add those, and that helps out the situation in this area. We are raising the road to get up to six feet, get up in this case to six and a half from the existing four. But here, since we're in the upland area, we're dealing with rainfall, we're trying to capture as much as we can so that it's not it's not all rushing downstream to uh impact the areas that are down by the river. And so in this case that looks like adding stormwater ponds, having that storage in existing areas where we can put those basins. Upgrading the piping just um like we talked before. Again, you might be able to see might be a little hard to see this hatching over here is a super fun site, and so trying to make sure that we're putting our detention basins outside of that where we can and dealing with the constraints of just a historical urban area that many places have to deal with these. Um and so it's all of those solutions working together as as a suite of layered solution to be able to handle a tenure event with three feet of sea level rise. So moving moving closer to the shipyard here. Uh, this is a real little problem area in a nexus of multiple corridors. Uh we did we did have a stakeholder meeting with the the shipyard folks specifically, and and they've uh more recently voiced a little bit of concerns about our for the solution here, but it's what we've got is a placeholder for perennial pavers and a large expansive surface parking. What we talked to them about potentially was doing like a doing a parking deck and getting some elevated parking to get the people that are parking there to work out of the flood, as well as like a mutually beneficial solution and then possibly doing a regional stormwater stormwater pond, but we really didn't want to we kind of wanted to stay in our lane, so to speak, and not get get too creative with with the solution, but just to show that a large expansive surface parking like that is a is a good candidate for a stormwater BNP retrofit or solution because it's just you know um is it the best use of space from a from an urban planning perspective as well, too, right? So uh it seemed like a good solution to us and and come couple of that with conveyance system upgrades and elevating the roadways in this area um as well. So somewhat more the same except for the the permeable paver parking areas for the for the shipyard.