After a recent question about the flooding in storms such as Harvey (Houston, TX 2017) I found a well-written article in The Atlantic about urban flooding from Harvey due, in large part, to stormwater runoff. Often we think of hurricane and related coastal flooding as being due to storm surge. Harvey was a different kind of beast. The water did not come in from the sea, but couldn’t get out to it fast enough. The last line of the article about Harvey’s flooding hits home and falls right in line with my mission:
For the average American concerned with the deluge, the best answer is to replace an occasional, morbid curiosity with flooding with a more sophisticated, long-term interest in stormwater management. (see full article here)
As the author mentioned earlier on in the piece, after the waters recede, so does the intensity of discussion, and the demands for better planning and development fade to a whisper. Until it rains again.
I met with some business owners a few months back that were dealing with flooding of their building during a fairly typical thunderstorm runoff event. This was a new phenomenon for them after 14 years of renting this space. This year alone it happened at least 3 times. We met, discussed the circumstances, and deduced that nearby development of previously undeveloped property (in the middle of Durham) is sending additional stormwater to the channel behind their building. The culvert that the water flows through under the adjacent roadway can only handle a certain amount of water during a storm. This culvert creates a bottleneck, if you will, and during storms the water fills the channel and adjacent floodplain (i.e. their parking lot and lower level of the building) until the water levels recede.
When I questioned them, I learned they had already spoken with the City Stormwater Management office as well as contacted the Department of Transportation (who maintains the culvert). Relief was not to be found on any front and thus is the plight of the home/business owner…development is continually permitted “upstream” and those below must bear the brunt.
The retired professor from Georgia that is quoted in the previously mentioned article is correct in his sentiment that less impervious surfaces (roads, sidewalks, roof tops, parking lots) is not necessarily the answer. Of course, that would be great and would certainly help, but he doesn’t feel it is a likely route to be taken by municipalities. Stricter stormwater management requirements such as zero-stormwater discharge from newly developed sites, appropriate updating of piping and culvert sizing for current/future capacity requirements to allow for more efficient removal of water, and ultimately anything else that can allow stormwater to re-enter the ground and make it’s way to drainages through subsurface flow would all be beneficial as well.
At the end of the day, one thing remains…it will rain again, it will flood again, don’t we at least want to be moving in the right direction and doing what we can to help those already suffering the consequences? This is a local issue and must be addressed as such. Stream buffers and green spaces are important in their own right, but they alone will not stop the urban flooding issues, not by a long shot.