While the Clean Water Act has paved the way for the ecological restoration industry, there’s a lot of debate about mitigation and the science behind restoration practices. The Ohio Valley ReSource asked watershed ecologist Matthew Baker, a researcher and professor at the University of Maryland, Baltimore County, about this industry, and the science and laws behind it.
On the importance of restoring impaired streams:
It turns out that streams are tremendously useful things, and our society benefits from them, often without us realizing it (e.g., streams supply for us, for surrounding ecosystems, and for downstream waters, they provide energy, remove or at least dilute pollution, process nutrients, transport materials and help process carbon…and water, streams provide a source of clean water!).
As human populations grow, land transformation is degrading stream ecosystems at a truly historic pace. We’re just exceptionally good at this. Most of us would like to think that “it’s okay, we can fix this later,” but the truth is, we’re still learning about the ways streams work as systems.
Because it is tough to design what we don’t fully comprehend, more often than not our restorations are a partial fix where we address one problem or one component of the system, often to the detriment of others, so restorations are mostly pale imitations of reality, and degradation is more often than not, a one-way street. In some parts of the country there are no longer any unimpaired streams we can use to remind us what we ought to be shooting for.
Stream ecologists see this as a tremendous loss, for all of us.
On the science of stream restoration today:
We’re very good at identifying degraded streams, but stream restoration is often focused on fixing symptoms not addressing causes, and in hindsight restorations often look like a hammer in search of a nail—focusing on the problems we can solve or thought we could, rather than the issues we don’t know how to address.
Restoration is getting better at understanding and mitigating changes in stream form and channel stability. Nevertheless, the success rate there is pretty spotty, even as we learn from our mistakes. I was just out surveying a system last week that a few years ago was touted as a model of restoration success, and now it’s all unraveling all over again. It’s sad, mostly because the folks that designed and built it had the best intentions and relied on the best available science at the time.
Generally, any approach focused just on channel stability is a bit like wagging the dog when most of the impacts arise in the up-slope watershed. What’s more difficult is dealing with processes that caused instability in the first place, especially when they occur outside of and away from the channel.
That’s where some practitioners are headed, but the jury is still out on whether we can accomplish this successfully. State of the art watershed-scale restorations that I’ve seen change so many things there are often unintended and undesirable consequences, I don’t want to criticize those efforts because they have the right idea, but neither do I want to communicate that we’ve got everything figured out. It’s complicated and streams are dynamic systems that we cannot expect to remain constant.
Even if we do figure out how to fix channel forms, still another problem is how to restore biota, like fish, insects and invertebrates, plant life, and bacteria that help ecosystems function and serve society. Life in streams is often dependent upon factors beyond what we have typically tried to restore. Characteristics of watersheds or connected channel networks both above and below ground can be important, and so can particular moments in time. Most folks aren’t used to tackling or conceptualizing problems at this scale.
So, no, it is not at all clear that we have gotten very good at restoration just yet; that doesn’t mean we shouldn’t try, but it is a work in progress, and my sense is that few people want to hear that, especially those who are invested in the idea that we can repair what we have done.
On existing environmental regulations and potential rollbacks:
I’m not a policy person, but the amount of impairment out there is pretty clear evidence that current regulations are not adequate for protecting streams and their watersheds.
My students are typically surprised to learn how limited regulations for protecting streams can be relative to the vast array of threats out there. That’s why scientists and practitioners alike are quite concerned about the implications of regulatory roll backs currently being considered at state and national levels. In my experience, when rules are relaxed or removed, regulatory action can become ambiguous, and under ambiguity the environment generally loses.
In my view, most regulatory structure in the U.S. is based on the implicit presumption that we can undo what we do. Take mitigation banking. This is a market based solution designed to reduce the time and hassle for developers while accumulating greater capital for specific projects and, I suppose, ensuring that some restoration gets done. Instead of fixing a stream themselves, a developer buys credits that fund restoration or mitigation elsewhere. It’s a pretty appealing idea, and certainly has created a booming industry.
The problem with mitigation banking is how we define what is equivalent for trading. The whole premise depends on standardization of restoration practice and commodification of the units being restored. What that means is we have to know that a practitioner is going to be able to reliably produce the expected outcome; that we have to be able to count it and measure its effects in order to trade it.
When credits are traded to conserve an undeveloped watershed from future development, this can make sense, but when 200 ft of a natural stream in one location can get traded for an artificial stream in another, as if one was equivalent to the other something is really wrong. Our system gives credit for this activity and what little monitoring is being done to assure that it is actually working it typically inadequate. So what benefits are we really trading, if any?
I get worried when it comes to trading on restoration because seems just too easy to look past the fact that we really do not know how to do it yet.
Note: This post was modified on April 3, 2017, to reflect a more expanded conversation with Professor Baker.