During pretty much any heavy rainfall, like we received yesterday, GM’s street floods. As in, the sidewalk turns into a river two inches deep. Basement steps on GM’s street regularly turn into waterfalls.
That’s a problem, but not the one GM wants to talk about today. The problem is that all that water, which accumulates so fast, goes down the storm drains. In the old parts of DC, like Georgetown, the storm drains and the household sewage lines are merged. And on nights like last night, they get overwhelmed.
Rather than back up the sewage into our homes, the system overflows into Rock Creek and the Potomac. It works, but it’s terrible for the environment. And the EPA sued the city’s water authority in 2004 for this practice. The agency-now known as DC Water-settled with the EPA and agreed to take remedial measures.
DC Water has been working on crafting those measures for years. Just last month it put forward a revised plan, one that affects Georgetown. Part of the original plan called for the construction of a giant tunnel running from Key Bridge down towards the Kennedy Center. This tunnel would serve as a giant underground reservoir to collect the water and store it until the sewage treatment plant is ready to deal with it. (This is a proposal GM wrote about way back in 2009.)
After hearing concerns about the impact of the tunnel, DC Water is now planning to instead rely heavily on green infrastructure to divert heavy rains from the sewers in the first place.
And that brings us back to GM’s street. On those heavy nights, like last night, it will take a whole lot of green roofs and rain gardens to divert those floods. There have been no ground-level design proposals that GM has seen to specify what level of construction is needed to satisfy the objectives. But given that it’s Georgetown, you know it will be ten times harder to build whatever it is that needs to be built.