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Design firms spend alot of money on liability insurance. Even with the insurance, becoming entangled in lawsuits - whether the are legitimate or not - is and expensive and unpleasant proposition. Time meeting with lawyers could be billable. Every liability insurance policy has a deductible that affects cash flow. The emotions involved distract from the core mission of design and making money. In short - it only makes sense to consider all of the possibilities to minimize liability. Designing stormwater management in traditional ways - that is, larger facilities that impound significant amounts of water - clearly has more liability than smaller, distributed BMPs such as bioretention. The possibility of liabilities such as drowning, vector diseases, or embankment failure may be considered by some to be remote, but they do exist. Because bioretention facilities are inherently smaller, impound less water depth, drain quickly, and usually do not require embankments, they represent less liability. And whatever a design professional can do to reduce or eliminate liability is just smart design. The following experience showed us firsthand that considering alternatives to steeply-sloped, deep impoundments is well worth the effort. Regardless of how remote the possibilities are, if a single family can be spared the below experience, we have done our job - as designers of built environments - at the highest level. We were recently called about a case that involved the near-drowning of a child in an extended detention facility. The details of the case were chilling, to say the least. After a storm event had ended, a couple of 8 year olds decided to play around a SWM facility located directly behind their townhomes. The facility had been designed per local regulations and both the engineer and contractor had, to their knowledge, done nothing wrong. The facility was fenced for safety, which only complicated the situation. Being 8 year olds, getting around the fence was not a problem for them, and it probably just added to the excitement. After they got over the fence, it was a fun time doing the cool stuff that boys like to do around water - searching for frogs along the water's edge, throwing rocks, etc. Until one child slipped on the wet steep slope into the impounded water. Chaos ensued as the other child attempted to run for help, an effort delayed by the fence. Neighbors and the mother tried their best to save the drowning child. She too, slipped into the water and nearly drowned. The submerged grass slope made it difficult for anyone to get stable footing or to exit the water - even though the water depth was not significant. Long story short, everyone survived, but the child suffered irreparable brain damage and will likely live the rest of his life in a vegetative state. Horribly unfortunate circumstances, to say the least. The design firm was just "doing their job" by following the local regulations and getting the plans approved. The contractor merely built what was on the plans. The municipality was exempt from liability. So who do you think the attorneys were gunning for? This experience changed the way we think about our designs. The professional liability issue is a no-brainer. But as designers of built environments, we have a duty the people who live and use the spaces we design.
"Present national loss statistics from dam failure fully justify the need for dam owners to better understand the public risks involved with dam ownership, the kinds of hazards that promote these risks and the reasons why dams fail. Public risk is high because people have been allowed to settle below dams in potential inundation zones and because new dams are being built in less than ideal sites. Other elements of risk include natural phenomena such as floods, earthquakes and landslides. These hazards threaten dam structures and their surroundings. Floods that exceed the capacity of a dam's spillway and then erode the dam or abutments are particularly hazardous, as is seismic activity that may cause cracking or seepage. Similarly, debris from landslides may block a dam's spillway and cause an overflow wave that erodes the abutments and ultimately weakens the structure. The International Commission of Large Dams (ICOLD) has determined that the three major categories of dam failure are 1) overtopping by flood, 2) foundation defects, and 3) piping. For earthen dams, the major reason for failure is piping or seepage. For concrete dams, the major reasons for failure are associated with foundations. Overtopping has been a significant cause of dam failure primarily in cases where there was an inadequate spillway." And that doesn't even consider the costs incurred for environmental cleanup below a breached dam. If you don't have to design an embankment, why do it? Imagine getting sued because someone alleges that your choice of BMP caused an outbreak of West Nile Virus or another disease. Who needs that, even if you think it is a remote possibility? Click here for an article by Marco E. Metzger, Dean F. Messer, Catherine L. Beitia, Charles M. Myers, and Vicki L. Kramer, which includes a side bar on how to design BMPs to avoid vectors.
Photo from Maryland Department of the Environment |
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If
you design a stormwater BMP with an embankment, you are assuming a certain level
of liability, even if you think it is remote. Whether it is the fault of a
design firm or contractor, embankment failures do happen. The