A few Common Sense Suggestions for Lake Restoration Projects
By: Joel Bleth, President, SolarBee, Inc., March 12, 2007
A lake restoration project should be a rewarding experience, creating community pride and worth for a job well done when the lake water quality clears up. Often lake stakeholders spend thousands of man-hours over several years discussing the lake's water quality problems and analyzing possible solutions. One or more studies by lake experts may be commissioned, followed by years of arduous efforts to raise money - sometimes millions of dollars - to restore the lake. But, all too often, after the "solution" is implemented the water quality is as poor as ever or else worse. Consequently, many lake groups are facing the same water quality problems today that they had years ago despite high expenditures in the interim.
This paper offers three common-sense suggestions to help lake stakeholders ensure that their lake restoration project is successful the first time:
SUGGESTION 1: Do not expect nutrient reduction to solve your water quality problems. Lake restoration projects which are focused mainly on reducing the availability of nutrients (phosphorus and/or nitrogen, internal loading or re-cycling and external loading) invariably fail to adequately improve the water quality. Because improving the water quality is less about affecting the quantity of nutrients than it is about affecting the fate of nutrients.
In lakes with good water quality, edible algae predominate and there are few, if any, blue-green algae blooms. Edible algae are typically small-celled species (green algae or diatoms) with high reproduction rates, and they uptake nutrients rapidly to create new algae cells. These cells are then eaten by zooplankton, which in turn are eaten by fish. Since the algae are always being cropped, the water remains clear, healthy, and productive all summer long. This is similar to the manner in which a healthy coral reef functions. Levels of nutrients such as phosphorus or nitrogen become irrelevant. More nutrients just create larger and happier fish! So lake restoration efforts should always have a primary focus of improving dominance by edible algae all summer long thus keeping the nutrients moving up the food chain. One sure way to accomplish this is through long-distance circulation equipment.
In lakes having poor water quality, inedible algae (usually blue-green algae) predominate. They are inedible because of their large cell size, indigestibility, and/or ability to produce toxins. When inedible algae dominate, the lake develops the classic symptoms of eutrophication: high standing crop of algal biomass, poor water clarity, high water toxicity, low biodiversity, undesirable taste and odor problems, high pH, episodes of low dissolved oxygen throughout the water column, and sometimes even fish kills and/or lake closures for public safety reasons. Furthermore, the slow decomposition of dead inedible algae at the lake bottom causes the buildup of organic muck, promoting the release of nutrients that can fuel the spread of invasive aquatic weeds and subsequent blue-green algae blooms.
Most blue-green algae can adjust their buoyancy to go down to the lake bottom at night for nutrients, and store the nutrients for later use, and then return to the surface during the day for sunlight. Because of this mobility, it is virtually impossible to eliminate blue-green algae blooms through nutrient reduction. It has never happened in a lake in the US - not even one time - even in projects where many millions of dollars were spent to try to limit availability of phosphorus and/or nitrogen by reducing external loading or internal re-cycling.
Summarized: To improve water quality in a lake, you have to somehow promote the production of edible algae while suppressing the production of inedible algae. Nutrient reduction doesn't work.
SUGGESTION 2: Request specific information on where the proposed restoration method has worked in the past. Usually you can find a lake expert experienced in lake development, watershed protection, and improving a lake for multiple uses. However, very few lake experts have ever managed a project where their recommendation significantly improved the water quality in a lake, for any length of time, without the ongoing (and never-ending) application of expensive toxic chemicals. To our knowledge, the only experts that can claim successes are those who have taken the time to learn about and recommend SolarBee circulators. We can provide a list of those experts, and almost 200 water bodies in the US and Canada where, since 2001, SolarBees have resolved water quality problems without the ongoing use of toxic chemicals. So ask your lake expert for a list of lakes where the recommended plan has specifically eliminated blue-green algae blooms and/or invasive weed infestations for an extended period of time without the use of toxic chemicals. Then locate and call residents living by those lakes, and ask them about the type of problems they had, the size and depth of their lake, the project details, and whether their observations support the expert's assessment. Finally, confirm that your lake is sufficiently similar to those lakes to provide confidence that your lake will achieve comparable results.
Summarized: Check numerous references - if the proposed restoration method has never worked before, it probably won't work this time either. It's better to learn this now rather than later.
SUGGESTION 3: Require accountability. It's true that lake restoration is not an exact science. However, it's also true that most lake restoration methods have been inadequate and/or ineffective every single time they have been attempted, and that many restoration projects have been far more experimental in nature than the lake stakeholders were led to believe. So, lake stakeholders would be wise to contractually minimize their financial risk of a failed lake restoration project.
First, the project's reasonable expectations and evaluation criteria should be clearly defined. Project evaluation could be tied to a number of different parameters, such as: a lake-user vote after one year, water clarity, results of periodic water testing, the reduction or avoidance of toxic algae blooms of the magnitude that would trigger a public safety notice based on World Health Organization guidelines, or other criteria specific to the lake. Keep in mind, too, that usually it's cost prohibitive to perform enough water and data analysis during the year to understand what happened in the lake (it would require thousands of water tests throughout the water column, and an analysis that looks at weather and nutrient input data as well), so in many cases, the most scientifically-useful information will be recorded observations made by the people that use the lake every day.
Second, stakeholders should require the lake consultant, and/or vendors of equipment or chemicals, to offer either: 1) a money-back guarantee in the event the restoration project is not successful at controlling algae blooms (or whatever problem the lake has) for at least two or three consecutive years, or else 2) a test or rental program, so the effectiveness of the proposed restoration technique can be demonstrated before the purchase is made.
Summarized: Performance matters in all other fields; lake restoration projects should no longer be an exception.
We hope this helps you. Best wishes for a successful lake restoration project! Click here to send questions or comments to Joel. |
