Following a massive rainstorm in late August that left flooding throughout the town of Colonial Beach, Town Manager Quinn Robertson spoke to a small group of concerned citizens at the Planning Commission meeting on the 27th.
The microburst storm, which brought in rain from five to eight inches in the Riverside Meadows and Classic Shore subdivision in Colonial Beach lasted less than an hour. With the ground already thoroughly saturated due to a much rainier than normal summer, the waters rose quickly.
Yards and roads were flooded with many homeowners flocking to Facebook and other social media to share pictures of the damages.
According to Robertson this was a 200 to 500 year storm. What that means is that the amount of rain, in that short of a time-period should only happen between every 200-500 years. Stormwater systems are built to withstand much shorter time period storms.
Even the strongest storm water systems such as the one that surrounds interstate 95 is only built to withstand a 50-year storm.
Robertson also discussed how the land in the Riverside Meadows area is on average six-feet above sea level. As with many coastal areas, the town of Colonial Beach is fairly flat. Originally farmland before the development of the property began, the land has a divergent water flow system due to the layout of the property.
One of the issues, that was not discussed, is how the developers from the 1980s were required to put in more of a storm water management system than they ever did. The developer built out much of the properties and then went bankrupt leaving the town to clean up the mess.
From gravel roads to improving storm water management, the area has been worked on a lot by the public works department to bring it to better standards. With the geographic information system maps just recently completed, the town will have the data needed to help design better water flow.
GIS maps go as far as showing 1 foot differences in elevation which will allow designs of storm water management that will work with the land.
Some issues that homeowners can help with that Robertson brought up involved the maintenance of ditches and culverts on their property. While the town has right of ways that go past the ditches on homes, homeowners are expected to upkeep them.
Cutting of grass and keeping the lines clear also falls on the property owners. Colonial Beach has 52 miles of roadways to keep clear according to Rob Murphy director of Public Works.
With the massive amount of ditches to keep clear, the town only gets to work on them about twice a year. Homeowners are asked to cut the grass in them, not to leave leaves or yard debris in them and to make sure that culverts used under driveways are done correctly.
Robertson mentioned that town residents sometimes leave raked materials in ditches, or burn them there, leaving the rain water to wash them into smaller areas and block all the water running behind them.
Culverts need to be of the proper diameter and materials to actually work as needed. Robertson said that property owners could work with the Public Works to find out what is appropriate for each situation.
Tidal Flooding was brought up by a resident of Potomac River Road between Maryland and Virginia avenues. For years the property owners and town have been locked in a battle over who actually owns the property between the beach and the homes.
For at least nine years the discussion has been ongoing as what used to be the boardwalk in that area continues to break down.
Robertson is looking for solutions with that property within the Army Corps of Engineers but says that it is a long process.