The Griffy Lake Nature Preserve on Bloomington’s north side is the perfect place to escape with a fishing pole. However, the area that is a peaceful natural retreat for many, is a work in progress for its keepers.
Invasive plants, pollution and erosion at Griffy Reservoir keep the City of Bloomington busy. Bloomington updated its master plan for the nature preserve in 2008. Two years later, the lake is doing better. But, take a look into the murky water and you can tell there is more work to be done.
“Since the master plan we’ve been working on controlling the invasive aquatic plants, continuing that effort,” said Steve Cotter, natural resources manager for Bloomington’s Parks and Recreation Department.
“We’ve taken some of the recommendations around the boathouse and improved the accessible parking area. And as part of that we’ve created a couple rain gardens to catch the run-off before it goes into the lake to try to improve the water quality down there.”
Cotter said a big problem for Griffy Lake is the eroding shoreline. Whenever it rains, more of the shore washes into the lake, causing the lake to shrink. Following recommendations in the 2008 plan, the city is bringing in rocks, logs and vegetation to reinforce the shoreline.
Bill Jones led the creation of the first Griffy Lake Management plan in the early 1980s. He is a professor at IU’s School of Public and Environmental Affairs, and an expert on watershed management.
“When it came to doing the updated master plan, it was actually kind of surprising that the original master plan in ‘83 was still being implemented twenty years after it was done,” said Jones. “Doesn’t mean it was a great plan or that the city was particularly slow. Just meant that these things take time, and the city’s been, I think, doing things right that way by not rushing in looking at the long term.”
A lot has changed since 1983, said Jones, especially the land surrounding the lake. New housing and apartment complexes have pushed more run-off and extra sediment to enter the lake. Also, more lawns are being over-fertilized, said Jones, which leads to increased plant growth in the water. Many more people visit the nature preserve than did 25 years ago. And there are more dogs, too.
The City of Bloomington hopes to start building an official dog park near the lake within the next year. The park will be further away from the lake than where people currently bring their dogs, which will help prevent dogs, and their by-products, from entering the lake.
Cotter noted that Griffy Lake is contaminated with mercury, and the state advises consumers to eat no more than one large fish a month from the lake. But mercury pollution is not unique to this watershed.
“One of the main reasons that swimming isn’t allowed here is because of erosion on the shoreline,” Cotter noted. “But there also are contaminates in the water. Unfortunately that’s true of virtually every stream and lake in Indiana. A lot of it is mercury contamination, which occurs as a result of our burning coal for electricity.”
Cotter hopes someday Griffy will be clean enough for swimming, but Jones cautions that lakes aren’t meant to look like chlorinated swimming pools. He said too many people have unrealistic expectations for lakes.
“Their concept of a great lake is perfectly clear water, no rooted plants growing anywhere, and lots of fish. Well you can’t have that,” said Jones.
“Fish need plants and nutrients to grow, and you can’t have bathtub conditions and great fish and it’s just not gonna work. It’s an ecosystem, and things grow and things die. And when you get too much growth then you get problems, and Griffy is kind of at that point. Too much growth or too much growth of the wrong species of plants that have gotten out of whack.”
Both Jones and Cotter hope people enjoy the natural wonders at Griffy, but also take commonsense steps to keep it viable in the future. They ask that people *don’t* over-fertilizer their yards, and don’t dump their aquariums into the lake.
“We feel very strongly that if people get out and enjoy what the natural world has to offer here that they’ll be stronger advocates for protecting it,” said Cotter. “And we think that’s a very important thing.”