Later this morning, Mayor Vincent Gray, Councilmember Kenyan McDuffie (D – Ward 5), and representatives from DC Water and District agencies, will announce the creation of a task force to address the flooding that has occurred in numerous basements in LeDroit Park and Bloomingdale since July.

The mayor and councilmember will hold the press conference today at 11:30 am at the park at triangle park at First Street and Florida Avenue NW.

During several downpours in July, the overtaxed sewers below Florida Avenue in LeDroit Park and below several streets in Bloomingdale backed up into residents’ basements.

DC Water, the semi-independent agency that manages the drinking water and sewer infrastructure, says the completion of new diversion sewer tunnels in 2025 will solve the problem for good. Waiting 13 years is little consolation for residents whose basements have flooded with diluted sewage.

Channel 4 has a short segment on Tuesday night’s flooding in Bloomingdale and LeDroit Park. The Post also has a story describing the sewage-drenched nightmare that struck many residents’ basements.

DC Water, which is responsible for the water pipes and sewers, left the following note in the comments section of yesterday’s post on the flooding:

Neighbors,

We’ve received a number of phone calls, tweets and email inquiries from Bloomingdale, LeDroit and Eckington customers who faced flooding last night. We’re so sorry to hear this has happened, and want to provide some background information as well as next steps.

The sewer system under this part of the District was installed generations ago by the federal government. At the time, populations were smaller, rains were likely lighter, and people weren’t commonly living in basements. The system was not designed to handle the volume it handles today. We inherited this system and are working to upgrade it, but this is not a fast, simple or inexpensive process.

We do clean every catch basin in the District once a year, and we come through flood-prone areas to do more cleaning every time a big storm is predicted. This one was not part of any weather forecast. The volume of rain in such a short period would overwhelm many catch basins as well.

The best short-term solution is a backflow preventer, which a licensed plumber can install. The long-term solution is enlarging the capacity of the sewer system, which will come as part of our Clean Rivers Project. It is a 20-year, $2.6 billion effort to build 13 miles of tunnels, which will capture stormwater and sewage and send them to our Blue Plains Advanced Wastewater Treatment Plant. The tunnel will start at Blue Plains and is under construction now. The last segment will make its way from RFK Stadium to Gallaudet University and will relieve the historic flooding problems in Bloomingdale, Eckington and Edgewood.

More details are here: http://www.dcwater.com/workzones/projects/anacostia_river_information_sheet.cfm. Customers with questions can feel free to email us at twitter@dcwater.com or call (202) 612-3400 anytime.

DC Water
Office of External Affairs

There are two things to glean from the comments section in yesterday’s post. One is that a number of Bloomingdale residents have said that flooding occurs in their basements more than once a year. Another is that DC Water’s solution, which includes the construction of an interceptor sewer tunnel, is years away.

DC Water will address residents on Monday, July 16 at 7 pm at St. George’s Episcopal Church at 2nd and U Streets NW.

During torrential downpours the Bloomingdale neighborhood experiences flooding. Yesterday evening’s storm flooded numerous Bloomindale basements and the intersection of Rhode Island Avenue, T Street, and First Street NW.

The Boundary Stone restaurant (116 Rhode Island Avenue NW) posted a photo of a flooded Rhode Island Avenue NW.

Why did this section of the street flood? DC Water, which runs the water pipes, sewers, and storm drains, blames the lack of pipe capacity in Bloomingdale.

A closer look at the 1861 Boschke map of the District of Columbia reveals that the northern reaches of Tiber Creek flowed right through Bloomingdale. In fact the creek flowed right where Rhode Island Avenue flooded at T Street NW.

Boschke map with modern streets superimposed

Whether the creek still flows underground in this location is something I will leave to experts. However, creeks, like all water, flow to the lowest point on the land. The creek’s former presence at this location suggests that the terrain slopes downward on all sides, directing rainwater to this critical flood point.

Ward 5 Councilmember Kenyan McDuffie (D) was on the scene and DC Water has promised to brief him soon on their Bloomingdale flood solution, which they say is on the way. Though this degree of flooding is rare, Bloomingdale residents will surely welcome and demand a permanent fix.

While strolling around our new park, you might have noticed this landscaped depression near the mural.

This is a rain garden.  The storm drains within the park empty into this garden so the ground has an opportunity to absorb rainwater.  Obviously there’s a limit to what the ground can absorb in a downpour, so the grate at the bottom of the photo carries the overflow into the sewers.

Under each street in areas of the city built before 1900 is a single pipe that carries both sewage and storm water. The problem with this combined system is that heavy rain storms force the combined system to overflow at 53 discharge points into Rock Creek, the Potomac, and the Anacostia.

Building these rain gardens helps alleviate the pressure on the sewer system during storms and thus helps protect the water quality of our rivers.

The Japanese Zelkova (Zelkova serrata) is one of the many species of trees regularly planted in DC

The District’s Urban Forestry Administration is responsible for planting street trees throughout the city. Just before Christmas we published a map (below) of the UFA’s 2010 tree planting list for LeDroit Park and Bloomingdale.

What a great joy it was to walk home Thursday night to spot a new Japanese zelkova (pictured above) taking root between the sidewalk and street beside our house.  A quick walk around the neighborhood revealed that the other trees had been planted, too.

View LeDroit Park-Bloomingdale Tree Planting Schedule in a larger map

After big snowstorms, the melting snow swells the Potomac and Anacostia for days.  The good news is that in older parts of Washington, including LeDroit Park, the heaps of gray slush— snow mixed with car grease, road salt, and road sand— will not be dumped straight into the rivers as it will be in the rest of the Washington area as the City Paper reports.

In older parts of the city built before 1900 (see the map), our sewers and our storm drains are the same system, meaning that the water leaving your sink joins up with the same water running into the street grates.  Only older cities have this combined system; the rest of the the Washington area, including newer parts of the District, have separate pipes for sewage and for storm water.

This combined system is usually considered an environmental problem, since occasional heavy rainfalls inundate the combined system, forcing it to eject both storm water and raw sewage into the rivers and Rock Creek for a few hours through 53 outfall points.

However, with melting snow, the system is reversed into an environmental virtue, since the melting slush—salt, sand, grease, and all— are filtered with household waste at the Blue Plains treatment plant at the southern end of the District.

Let’s call this the combined system paradox: an environmental threat to the city’s waterways in the spring and summer becomes an environmental steward when winter snows melt.