News & Events

Aquatic Vegetation Management Plan Project

July 22, 2022

Update #16 July 22, 2022

The Eurasian watermilfoil treatment was completed on June 1. The contractor checked the treatment areas on Clear and Round Lakes. He reports there's less than one acre of invasive milfoil left standing. A small patch was found in Marina Bay. The big question now is how much will emerge next spring? The areas previously colonized by the invasive milfoil contain mostly native pondweeds now, which is encouraging.

It's important to note that in the central flat on Clear Lake the milfoil has largely been replaced by densely growing sago pondweed, a favored food of many waterfowl. Many of these plants are on or near the surface, so boat traffic will still be producing prop-cuts and possibly fouling their props if they are moving through this area.

Concerns were raised about possible effects on native plants at Round Lake, but overall vegetation is looking pretty healthy and happy.

Aquatic Enhancement and Survey will complete a Tier II survey yet this summer and update our Aquatic Vegetation Management Plan. This along with survey work in Spring 2023 will guide the treatment efforts next May/June.

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Update #15 June 24, 2022

It’s been three weeks since Aquatic Enhancement & Survey (AES) completed the treatment of 52 acres of Eurasian watermilfoil on Clear Lake and just under 7 acres on Round Lake on June 1st. Since then, we've received a few questions from the community and want to respond to the questions, update everyone on what we are seeing and describe what next steps are planned. We asked Scott Banfield of AES to respond to specific questions about treatment.

Q: We are seeing algae in Round Lake. Is the treatment responsible for this?

A. (Scott from AES). Parts of Round Lake, especially the eastern (downwind) shore, have a good bit of filamentous algae building up along the shoreline based on the photos you shared. We don't usually see an increase in filamentous algae (sometimes commonly called pond scum) in response to natural lake treatments like we performed at Round Lake but it's certainly possible the treatment contributed to a normal occurrence of this algae buildup. While filamentous algae is unsightly and can be a nuisance, it is not considered a health threat to people or animals.

Filamentous algae generally grows on the lake bottom like green fur on a normal basis. It often becomes buoyant when gas bubbles are trapped in it. After it hits the surface, prevailing winds can move it to the downwind side of the lake where it gathers along the shoreline. Usually this is a short-term situation as weather conditions and growth patterns break up the algae on the shoreline. Generally, the shoreline will return to normal as the season progresses.

It’s important to know that I receive phone calls every year from people with filamentous algae accumulating along their shoreline where they had never noticed it before. It's pretty common for this to happen both on lakes that are treated and also on untreated lakes.

It's normal to have a temporary decrease in water clarity following a treatment for aquatic plants. Decomposing plants release nutrients which can spur the growth of filamentous algae. You also might have a decrease in water clarity as a result of organic acids being released from the plants as they decompose. How noticeable these effects are depends on the size of the treatment relative to the size and volume of the lake and other factors. Because we treated a relatively large portion of Round Lake, I would expect the natural results I’ve described to be more noticeable there compared to the larger Clear Lake.

Q: We are still seeing a lot of floating plant debris. Is this from the treatment?

A. (Scott from AES). It’s natural to assume the invasive plant treatments might be causing this phenomena. However, when we treat aquatic plants they tend to drop in place and decompose rather than uprooting. We don't usually see our target plants floating on the surface of the lake after the treatment. Since we are more than 20 days beyond the treatment, none of the target plants are still green and healthy looking. Most or all of the target plants would have dropped by this point.

Since only a portion of the Eurasian watermilfoil infesting Clear Lake was treated in this first year of the treatment plan, the green plant fragments reported floating are more likely untreated prop-cut plants generated by boat traffic moving through some of the shallower areas of the lake. The best way to minimize this is for boats to navigate through the deeper areas of the lake whenever possible.

As invasive plant populations are further reduced in coming seasons, you can expect fewer floaters, but some amount of floating plant debris will likely still be around. If you look at the floating plant fragments carefully, you will see native as well as invasive plants floating. Some floaters will likely always be present in a healthy lake with a high recreational use, which is how I would describe Clear and Round Lakes.

Q. It seems like I’m seeing more dead fish than usual this year. Is this related to the treatment of the invasive aquatic plants?

A. (Scott from AES). It's natural to assume that if a lake has been treated and dead fish are seen, the fish have died as a result of the treatment. However, products used to treat aquatic plants generally have quite low toxicity to fish and other forms of aquatic life. They are engineered to be highly effective on target plants and leave other forms of wildlife unharmed. When properly performed, plant management can be quite compatible with a healthy fishery.

When it comes to dead fish on our beaches or floating in any lake, it's important to consider a couple of general observations to diagnose possible causes.

Fishkills resulting from toxic substances finding their way into the water will generally be hardest on the smallest fish. Most of the fish noted will be smaller, younger fish. If a low-oxygen situation causes a fishkill, it will typically be hardest on the largest fish. It's also important to consider the numbers of dead or dying fish present. A small number of dead or dying fish on a given day is normal, while hundreds of dead fish is more of a cause for alarm and worthy of investigation.

Seeing dead fish in lakes is pretty common in the early spring after the ice melts and it's also pretty common at this time of year (late spring, early summer). Spawning instincts and relatively rapid water temperature changes can place lots of stress on adult fish at this time of year and some number of fish are regularly lost.

Our treatment in early June went as expected and was very unlikely to be a cause of significant fishkill.

Q. Is the Indiana Department of Natural Resources (IDNR) involved in the recent treatment of invasive aquatic plants?

A. Yes. No treatment can occur without the submission of a detailed treatment plan and approval of the IDNR. The recent treatment plan was submitted to and approved by the IDNR.

Q. Is treatment really necessary? What happens if we just let nature take its course?

A. As Dr. Robin Scribailo told us at the public meeting held in October 2021, Eurasian watermilfoil is extremely aggressive and over time can crowd out all native aquatic species, changing the current ecosystem of our lakes. Recreation, fishing and boating could no longer be possible. The community survey conducted by the Conservancy last fall strongly supported pursuing treatment. Regular updates of plans and treatment notices have been posted on the Conservancy website, sent in eBlasts and posted on social media. You can review them below. Sign up here to receive regular Conservancy communications.

Q. What is the next step in the treatment plan?

A. In July-August, AES will conduct an aquatic vegetation survey. This assessment will determine the extent and location of all aquatic plants on Clear and Round Lakes, including Eurasian watermilfoil. This assessment will be reviewed by the Conservancy and AES to begin planning for 2023 and it will also be filed with the IDNR. The second treatment plan proposed must be filed with and approved by the IDNR.

We expect the second phase of treatment will start in late spring 2023, starting with a lake-wide assessment of invasive aquatic plants and followed with a late-spring treatment of additional infested areas.

Eurasian watermilfoil will likely never be fully eradicated, so we expect treatments to continue indefinitely, but at lessening levels over time.

Update #14 June 1, 2022

The battle begins...

The treatment of 52 acres of Eurasian watermilfoil on Clear Lake and 6.8 acres on Round Lake is being completed today, Wednesday, June 1st. The areas shaded in purple below are the target areas.

We can expect to see the plants begin to brown out in a few weeks and drop to the bottom as they die.

EWM 2022 treatment areas

Do you see a yellow flag on your shoreline?
Water-use restrictions only apply within 100 feet of the treatment areas. Based on the above treatment map you can see there's only a handful of areas on Clear Lake where they have posted. Those include the area near the launch, Paradise Point, the South part of the Island, and a stretch of shoreline along East Clear Lake Drive. In a couple of these areas the treatment is more than 100 feet out, but it was posted anyway. All of Round Lake will be posted.

The water-use restrictions include:
1) No turf irrigation - 0 days (does not affect grasses)
2) No irrigation of shrubs, ornamentals, garden plants - 7 days
3) No livestock watering - 30 days
4) No swimming - 1 day*

*The one day "no swimming" is not required per the label on ProcellaCOR. Aquatic Enhancement & Survey takes this extra measure for the benefit of the community.

Posted areas

Update #13 May 25, 2022

Treatment is planned for Wednesday, June 1st.

All colored areas represent Eurasian watermilfoil growth on the map below. The Indiana Department of Natural Resources (IDNR) has permitted the treatment of 52 acres on Clear Lake using the chemical ProcellaCOR. Based on survey rake scores of 5 (high presence of EWM) and high boat traffic areas, the 2022 treatment will focus on the purple areas numbered 1 - 5 on Clear Lake.

Round Lake has slightly more EWM area (6.8 acres) than permitted (6 acres) for treatment using ProcellaCOR. Aquatic Enhancement & Survey will treat all the EWM at Round Lake if an amendment to add 0.8 acres is granted from the IDNR. If the amendment is not granted, the permitted 6 acres will be treated.

EWM 2022 treatment areas

Water-use restrictions only apply within 100 feet of the treatment areas. Before treatment day, Aquatic Enhancement & Survey will post a landscaping flag detailing water use restrictions. Based on the above treatment map you can see there's only a handful of areas on Clear Lake where they will post. Those include the area near the launch, Paradise Point, the South part of the Island, and a stretch of shoreline along East Clear Lake Drive. In a couple of these areas the treatment is more than 100 feet out, but it will be posted anyway. All of Round Lake will be posted.

The water-use restrictions include:
1) No turf irrigation - 0 days (does not affect grasses)
2) No irrigation of shrubs, ornamentals, garden plants - 7 days
3) No livestock watering - 30 days
4) No swimming - 1 day*

Many thanks to the following for their project support:
Clear Lake Association, Anonymous, Ann Brennan, Jim & Karen Bushey, Sue Compo, Bill & Judy Greffin, Cindy & Steve King, Molly & Jeffrey Nagle, Matt & Claire Timmer, Denny & Sheryl Vetter, and the Lake & River Enhancement Grant program.

Update #13 May 28, 2022

We made the match! Many thanks to Jim and Annie Skinner for the $4,000 matching opportunity. And many thanks to everyone who contributed. More details to come!

Update #13 May 20, 2022

Aquatic Enhancement & Survey has completed their survey work identifying the invasive Eurasian watermilfoil areas on Clear and Round Lakes, highlighted in red on the map below.

EWM identified in 2022 spring survey

Treatment locations and timeline to come.

Curly leaf-pondweed surveys were completed and very little was observed. This is not too surprising as curly-leaf emergence can vary significantly from year-to-year, according to Scott with Aquatic Enhancement & Survey. Growth was not significant enough to warrant treatment in 2022. Growth will be surveyed in early 2023.

Update #12 April 25, 2022

We are glad to share that Aquatic Enhancement & Survey is the contractor selected to complete the invasive species control this spring and summer. The permit application was approved by the Indiana Department of Natural Resources to treat Eurasian watermilfoil and curly-leaf pondweed in Clear Lake and Round Lake. Scott and his team have been on the lakes to assess the infestation of curly-leaf, pictured below. Check back for the timeline and treatment approach.

Curly-leaf pondweed
Photo credit: thepondshop.com

Update #11 March 28, 2022

The final report is available for viewing and download from the survey work completed last summer. The Aquatic Vegetation Management Five-Year Plan can be accessed here. Results from this study are important for understanding the level of infestation of invasive aquatic plants and the location.

Update #10 March 15, 2022

IDNR has awarded $8,000 through the Lake & River Enhancement Grant program to support the treatment project and follow up survey work.

Update #9 February 25, 2022

The next step will be to apply for a permit from the IDNR to complete treatment beginning in 2022. Check back for this update to learn where we will be allowed to treat, what method will be used, and when the treatments will begin.

Update #8 January 15, 2022

CLTLC's Board reviewed treatment options presented through a scoring matrix put together by members of the Water Quality Committee and Staff. Based on the scoring of safety, effectiveness and cost factors, the Board approved a treatment approach for submission to the IDNR.

An application was made to the Lake & River Enhancement grant program for funding of treatment and control of the aquatic invasive species identified in the updated AVMP from the summer of 2021.

Update #7 October 2021

A community meeting was held to share findings from the survey work. View the recording here.

The community was invited to fill out a survey to help inform the decision making process going forward.

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Update #6 May - August 2021

Survey work was completed by Dr. Scribailo of Aquatic Ecosystem Services to identify the location and level of infestation of the aquatic invasive plants.

Update #5 February, March, April 2021

Community support from Matt & Claire Timmer, Sue Compo, an anonymous donor, and the Clear Lake Association was secured to move forward on the AVMP project.

Image Description HereWe really appreciate this support!

The Water Quality Committee put a scope of work together for the updated AVMP project.

The project went out to bid and Aquatic Ecosystem Services was selected.

Update #4 January 2021

The Conservancy applied for Lake & River Enhancement grant to request funding to get an updated Aquatic Vegetation Management Plan (AVMP), a required step by the Indiana Deparment of Natural Resources (IDNR) in the treatment process.

Funding was denied.

Update #3 September 2020

Water Quality Member Matt Rippe uploaded GPS tracks of known and estimated sites with EWM.

Dr. Scribailo visited Clear Lake and Round Lake to help us understand the level of infestation and plan next steps.

Update #2 August 2020

Members of our volunteer Water Quality Committee collected a sample and shipped it to Dr. Robin Scribailo at Purdue University. He confirmed the presence of invasive and non-native, Eurasian Watermilfoil (EWM).

An "Ask Bridget" was sent out.

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Update #1 July 2020

Bill Geiger took Bridget Harrison up in his plane to see the aerial view of the increased plant life in Clear Lake.

Connor Oiler flew his drone and collected valuable aerial footage of the location of the aquatic plants.

Several community members voiced concern.

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Cover photo credit: Connor Oiler


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