New Paper by Dick Osgood Addresses Inadequacy of Best Management Practices

Long time NALMS member, consultant, and past speaker at NECNALMS Dick Osgood has published a paper on the inadequacy of normal best management practices (BMPs) to restore eutrophic lakes to compliance with water quality standards. Dick’s paper, in the September issue of Inland Waters, is based on a review of many restoration efforts, documenting an opinion held by a number of long-term practitioners in lake management for some time. In essence, the degradation caused by development and agriculture in many lakes is not sufficiently counteracted by BMPs as applied in actual cases.

In some cases the application has not been at a scale sufficient to reduce loading enough to meet standards, but in many cases even maximum application is not enough to offset the inputs from the watershed. Where the ratio of watershed to lake area is <10:1, the probability of success through watershed BMPs increases, but there are few cases of success where the ratio is larger. Most BMPs reduce loading by no more than 50%, while development and agriculture tend to increase loading by tenfold or more.

While the paper is new, the debate is not, and there has been considerable defensive posturing by watershed management enthusiasts and institutions. But this paper is not saying that watershed management can’t work, only that we have been unsuccessful applying it in a manner that leads to success. Some of this is a result of technical limitations (e.g., heavily urbanized watersheds will never function like natural landscapes), but a lot of it is related to institutional failure (e.g., lack of funding, regulatory restrictions, inadequate jurisdiction). And if what we desire is success, measured as compliance with water quality standards for lakes, we need to do what works, not what is philosophically satisfying, politically popular, or simply affordable. In-lake management does not guarantee success, but has a better track record than watershed management. Some combination of watershed and in-lake methods is likely to be needed in most cases, but it seems clear that in-lake management deserves more attention than it has been given in many years by agencies responsible for environmental management and regulation.

One thought on “New Paper by Dick Osgood Addresses Inadequacy of Best Management Practices”

  1. Been sayin’ that for years, since the first NALMS Conference- Haloween 1982, Vancouver.
    Yes, watershed management is always a necessary step- for now and the future. Always. But for many lake ecosystems there isn’t enough “restoration” that can be accomplished on land that will improve lake conditions enough. TMDLs that call for >50, 60, 75% external load reductions (while making sure we don’t decrease N disproportionately)? Not going to reach the goal, but keep trying. Fortunately, there are management techniques that can improve the lake’s ability to deal with external loads while not expressing poor quality, habitat, and aesthetic qualities. Manage the capacities of the water body also. Everyone focuses entirely on the “loading rates”, but that is only half of the “State Equation”- what about removals that lower TP State? Anaerobic respiration pathways are incredibly important, especially for management and improvement. Do we ever examine that, even where cyanobacteria blooms proliferate? Most lakes produce far more carbon dioxide than they consume oxygen, RQ often over 3.0. Back in the 70s right after the CWA was passed, and especially in the 80s when we actually had a Clean Lakes Program (Phase I, II, and III), we were still figuring out how to do technology transfer from academic ecosystem ecology (including watershed) and limnology to applied lake management science. Then, sometime in the 90s someone decided (probably in government) that “now we know its the watershed”, and the entire focus went to managing land, 319 was funded, but not 314. I know an exaggeration, but not by much. We need to remember that we don’t know enough to KNOW, and never will. The whole ecosystem requires management, there are some very effective ways to improve a lake from within, in addition to protecting against what’s coming in. Both are needed in most lakes that express a condition local folks get alarmed about.
    I can say though, on a positive ending note, that in the 2010s I’ve noticed some shift back to taking a look at internal structure and function in addition to watershed, the whole ecosystem- starting to recognize that nitrate might be beneficial on the bottom (not a “pollutant”), expanding the depth of epilimnetic mixing to decrease cyanobacteria, developing an aluminum nitrate coagulant for lake management (so the other side of the molecule is denitrified), transferring the principals of ANAMMOX to lake management (that one is intriguing). Lots of potential for new, very innovative, in-lake methods. We just need to get back to looking for them.

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