September 4, 2012 UpdateBloomingdale/LeDroit Park Update - September 4, 2012
We recognize that Labor Day weekend was a trying time for many of you. While the majority of the DC metro area did not experience significant rainfall the evening of Sunday, September 2, a slow-moving shower affected Bloomingdale, LeDroit Park and other neighborhoods north of downtown. Children's Hospital, just to the north, recorded more than 3.5 inches of rain in about 2 hours. This was an extraordinary storm.
Some of you experienced flooding for the first time on Sunday. If so, we need to hear from you so we can confirm the boundaries of the area that experienced flooding related to these intense rain events. Please take a moment to fill out our Bloomingdale and LeDroit Park community survey.
Following are some updates on the weekend, our investigation of the flooding in July and the short-term solutions we are recommending to homeowners.
Catch Basins. Because the local weather forecasts called for rain over the weekend from the remnants of Hurricane Isaac, we were on scene checking and clearing catch basins last Friday. Contrary to some reports, we did have crews in your neighborhoods during the storm and called in additional backup. We rechecked and re-cleaned the catch basins after the storm in case additional debris washed in.
Flooding Reports. We received 27 calls about flooding the night of the storm, 13 of which were from Bloomingdale or LeDroit Park. We received about 10 additional reports via Twitter or email. Metro had to close three stations because of flooding, but this was due to the failure of pumps that keep water from entering the subway - not related to the sewer system. Similarly, not every residential flood last Sunday was the result of overloaded sewer capacity. Clogged downspouts, drains and sewer laterals, along with groundwater infiltration, are other possible causes of flooding.
Email Responses. A number of customers have complained that their emails are going unanswered. Our approach has been to respond to concerns and questions about specific properties and to schedule visits from our staff. We have saved discussion of programs or investigations that affect multiple properties for community updates like this one, mostly because it's our best way to answer the same question from more than one customer at the same time. As we work toward short- and medium-term solutions to flooding in Bloomingdale and LeDroit Park, we simply don't have the staff resources to engage in individual debates about the effectiveness of the work we're doing.
Storm Information. Using information from the rain gauge at our nearby Bryant Street Pumping Station, DC Water engineers analyzed major rainfall events from December 2006 to the present. They focused on the intensity (amount of rainfall) and the duration. To summarize, the three storms of July 2012 were all in the top four most intense storms in the last six years, and two of the storms were in the top three for most accumulation in depth. In addition, the storms occurred within just nine days of each other. The ground surface was saturated after the first storms, leading to more runoff. On September 2, Bryant Street received 2.79 inches of rain in two hours. This would make it slightly more intense than the July 10 storm. While it is entirely possible that something within the sewer system made the flooding worse (and we continue to investigate this possibility), Bloomingdale and LeDroit Park have not received this level of rainfall in nearly six years if not longer. The engineering solutions we are exploring will account for the possibility of more frequent, more intense storms in the future.
Inflatable Dams. We understand that there is a concern that inflatable dams that work to halt inflow of river water into the system in high river level events may have helped cause the flooding. We are confident that the dams do not cause nor contribute to flooding in Bloomingdale or LeDroit Park. The dams function in part as backflow preventers to the sewer system from the river - so high flow in the river, whether caused by high tide or winds, does not push back up the lines. The primary purpose of the dams is to limit dry-weather overflows to the river, but many miles away from Bloomingdale. If the Bloomingdale area flooding was related to the existence or performance of the inflatable dams, we would have seen flooding farther down the line, or considerably east of Bloomingdale. We saw no flooding down the line in any of the four events that affected your neighborhoods.
Individual Homeowner Programs. Many short-term steps to prevent or mitigate flooding are still available at the property level. Our backflow preventer rebate program is open for business, and we have mailed application materials to every address in the affected area. You can also download these from our website. The two workshops on backflow preventers that we are hosting with the Bloomingdale Civic Association, featuring experts from the Backflow Prevention Institute, take place Thursday at 7 p.m. and Saturday at 2 p.m. The location is our Bryant Street Pumping Station at 300 Bryant Street, NW. Please note that these workshops are specific to the topic of backflow prevention only.
DC Water continues to offer individual consultations to residents about how to prevent overland flooding (such as through a door or over a stairwell). This is a service contracted from Arcadis Engineering., and provided at no cost to residents. For more information or to schedule a consultation, please visit this page.
I continue to co-chair the Mayor's Task Force on Prevention of Flooding in the Bloomingdale and LeDroit Park Neighborhoods. In the next few days, I hope to report back to you on some initiatives we're approaching with other agencies of the District Government, as well as the solutions our team of 10 engineers has been examining since July.
We absolutely agree with Councilmember McDuffie and others who have said that our customers should not have to live in constant apprehension every time rain is in the forecast. Please be assured that I have made this issue DC Water's top priority. Along with the steps I have already mentioned and the information we will share shortly, our $600 million Northeast Boundary Tunnel portion of the Clean Rivers Project represents the single largest investment of funds in this neighborhood or any neighborhood in the District since the Metro system was constructed.
We will continue to do more.
George S. Hawkins