New developments plus severe weather could overwhelm water systems
“I would say we’re at the borderline of the capacity for that pipe based on our calculations,” Morgantown Utility Board Stormwater Senior Engineer Ken Hacker told the Morgantown Planning Commission.
At issue is the proposed La Dolce Vita development, at the corner of Van Voorhis and Southview Street. In light of last year’s horrendous floods, residents at neighboring Heritage Place are nervous the development could overwhelm the existing stormwater system and make flooding even worse. An engineer they hired fears this will be the case; an engineer for La Dolce Vita says it won’t be; and MUB isn’t quite sure how the existing infrastructure will hold up.
According to Hacker, the current stormwater system should be able to withstand anything the development and Mother Nature throw at it — up to a 50-year storm. Last year, Morgantown experienced two 100-year storms/floods in less than two months.
The terms “50-year flood” or “100-year storm” don’t refer to the number of years between weather events, but the likelihood that kind of event happens in a given year. For example, a 100-year storm has about a 1% (1 in 100) chance of happening in any year, or 2% for a 50-year flood (1 in 50, or 2 in 100). A home on a 100-year floodplain theoretically has a 1% chance of flooding at any time.
If you’re looking at the bigger picture, though, the numbers are slightly different. There may only be a 2% chance of a 50-year storm this year, but over the course of 10 years, likelihood of such a storm increases to 18%; over 20 years, 33%, so on and so forth. In short: A weather event more severe than a 50-year storm or flood will happen sooner or later — it’s just a question of when.
Unfortunately, climate change is increasing the frequency and severity of storms and floods, and even the amount of precipitation from non-severe weather events. The U.S. Global Change Research Program says the Northeast (including West Virginia) is expected to see 20% more annual precipitation by the end of the century, and any single severe storm could drop 40% more snow or rain than it does now.
At the planning commission meeting, Hacker and the commissioners acknowledged this isn’t an ideal situation, but their hands are tied. The pipe will likely hold up, and the development’s submitted plan meets all the requirements listed in city code, but something is liable to go wrong. It’s just a matter of time.
The solution is two-part: First, MUB should update the stormwater system serving both the new development and the residents at Heritage Place so it can handle higher daily intakes as well as sudden flash flooding. The second is for the City of Morgantown to update the stormwater plan requirements in city code for future developments to take into account more frequent and more severe weather events.
We know the factors that contribute to the type of horrific flooding we saw last summer. Now we must account for those in all future developments to minimize the chance of it happening again.
