United States Army Corps of Engineers (USACE) Dr. Marion Divers presented at the Chautauqua Lake Symposium, held Saturday at the Chautauqua Harbor Hotel. Additionally, USACE Pittsburgh District officials will host a virtual meeting on April 9 from 6 to 8 p.m. to provide updates regarding its Chautauqua Lake Aquatic Ecosystem Restoration Project.

The United States Army Corps of Engineers (USACE) is addressing several issues surrounding Chautauqua Lake and will provide updates regarding its Chautauqua Lake Aquatic Ecosystem Restoration Project.

Army Corps of Engineers Pittsburgh District will host a virtual meeting on April 9, from 6 to 8 p.m., regarding the Corp’s multiyear effort to restore the aquatic ecosystem at Chautauqua Lake. The meeting will consist of a presentation followed by a question-and-answer session. For participants who cannot join at the start of the meeting, district staff will repeat the presentation after the initial Q and A session.

Participants can join the virtual meeting by following this link usace1.webex.com/usace1/j.php?MTID=m74dfc32da259985be0cca315ce704fba. To join the meeting, participants must enter the link in their browser, select “Call Me,” enter their phone number, and click “Join the Meeting.” Additionally, those unable to join the WebEx meeting can join via phone by calling the toll-free number 844-800-2712 and entering the access code 2819-962-2945.

ARMY CORPS PROVIDES UPDATE

Dr. Marion Divers of the U.S. Army Corps of Engineers was a guest speaker at the 2025 Chautauqua Lake Symposium hosted by the county on Saturday. She spoke at length about the USACE’s approach to helping restore and revitalize the lake’s natural resources.

Divers said public comment charettes held by the Army Corps of Engineers in January revealed concerns from those attending about sedimentation caused by shoreline and streambank erosion caused by land development and agricultural practices along the lake’s shoreline and the watershed. That sedimentation has impacted the quality and availability of aquatic and deep-water habitats in the lake.

“We pulled all of this information from the charette participants and really then started to consider what management measures we would like to use to address these,” Divers said.

CONCERNS, OPPORTUNITIES RAISED BY PUBLIC

Concerns were also raised by high nutrient levels caused by internal and external loading resulting from wind and wave action in the lake and runoff from the watershed that are degrading habitat parameters for native species in the lake. Lastly, sedimentation, nutrients and changing precipitation and temperature have resulted in favorable conditions for the growth of invasive and nuisance plants in the lake that threaten native species and impact local economics and recreation opportunities. Divers said general objectives for the Army Corps of Engineers include increasing the quality of aquatic habitat in Chautauqua Lake, increase the quantity of available aquatic habitat in the lake and improving the connectivity of aquatic habitats in the lake.

Opportunities identified in the public meetings include improving water management of the lake, including understanding lake level and hydrologic conditions, improving local residents’ ability to withstand and respond to impacts from climate change and development over time, enhancing recreation opportunities when compatible with overall ecosystem restoration, increasing public education and understanding of the lake ecosystem, reducing maintenance costs for water supply infrastructure, reducing costs for existing management efforts, strengthening the region’s economy, improving water quality in the lake including harmful algal blooms, temperature, trophic level indices and addressing flooding issues on upstream tributaries along the lake and to downstream communities.

Things to avoid include affecting water levels that are required for recreation and maintained by the Warner Dam, impacting public use of the lake permanently, impacting public and private water supplies within the lake and increasing flooding in surrounding communities. Additions to consider are possible negative impact to fisheries and downstream flow required for utilities.

Considerations that inform the Army Corps of Engineers’ work include existing programs that include the Jefferson Project, work by the county, towns, villages, DEC and U.S. Geologic Services; the thales of habitat that the project team should be designing, the impact of changing precipitation and temperature on plans for the lake, real estate considerations that include areas that should perhaps be avoided for development, how dredging the lake would affect lake levels required for recreation, and the use of insect herbivores in the lake. The Army Corps of Engineers is also considering work that needs to happen in the future without the Army Corps of Engineers to make sure its recommendations are sustained in the future.

‘FUTURE WITHOUT PROJECT’

“I told you all that we also identified what we call the FWOP, or future without project,” Divers said. “What happens if we don’t do anything? We think about this carefully. We consider this outcome so that we have a baseline to compare our plan to. This is important. We identified a number of future without project considerations that are projected to continue.”

Divers said those considerations include streambank and shoreline erosion continuing due to agriculture and increased residential development, increasing runoff and sedimentation that lead to continued nutrient issues in the lake, decreasing species diversity and abundance, further loss of habitat and ecosystem function degradation caused by harmful algal blooms and nutrients, increased sediment that could cause the lake capacity to change, hydrology being influenced by climate trends that include higher water temperatures, changing precipitation patterns and less ice cover, increased coverage in the lake by invasive species, harmful algal blooms creating issues with drinking water and recreational use of the lake and economic impacts from lost recreation opportunities as rentals, gas and food sales decrease.

POSSIBLE MANAGEMENT MEASURES

Management measures include dredging a portion of the lake, herbicides, mechanical removal of weeds, using insects to basically eat invasive plants, shoreline cleanup, invasive fish or mussel species management, installation of nanobubblers, enhanced or expanded vegetated buffers, replacing hard armoring along the shoreline with natural features, construction of floating wetlands, beneficial use of dredged materials, water mixing in the north basin to break down the thermocline and reduce anoxia, proactive measures to detect new invasive species – such as boat washes, additional treatments for public water systems and upgrades to wastewater treatment plants, private septic system upgrades, natural methods to sequesterer internal loading – such as moss, conservation of critical wetlands areas, adjusting the water management plans, no wake zones and speed limits, stricter development regulations for stormwater, constructing shoreline wetlands, streambank stabilization of tributaries, nutrient inactivation that could include in-lake aluminum sulfate or sodium aluminate treatments, constructing bioswales, vegetative filter strips, retention or infiltration ponds; sediment traps, informational signs, creation of stormwater management plans, Warner Dam fish passage improvements and fish passage improvements throughout the watershed.

Comments can be made at https://lrd.usace.army.mil/chautauqua-lake-aquatic-ecosystem-restoration-project/ or emailing CELRP-Chautauqua-AER@usace.army.mil.