Focus on Parks Environmental Services:

Cleaning up municipal waterways

By DENISE FEDOROW | The Municipal

Whether you live on the East Coast, in the South, the Midwest or on the West Coast, if there are municipal ponds, lakes or beaches within city limits, at some point, you’re faced with how to clean or maintain those resources. Invasive plants, waterfowl or careless acts by residents or visitors all can turn a beautiful water feature into a smelly swamp if not maintained.

The Municipal spoke to officials in several cities about the steps they’ve taken or plan to take to protect their water resources.

In Sebastian, Fla., officials worked on an integrated pest management plan adopted at the end of August. Sebastian has several stormwater ponds, stormwater conveyance canals and ponds in city parks.

City Manager Paul Carlisle said, “With every body of water in Florida, the problem is overgrowth of vegetation, and trying to manage that is always a challenge.”

The city’s completed integrated pest management plan for the stormwater system employs manual or organic methods, with the use of chemicals, herbicides and fertilizers being only as needed and in the least invasive way.

In Garden Club Park, the city put in probiotics and upgraded aeration. Carlisle said three tests of soil and sediment on the bottom of the pond were conducted so the city will have control data moving ABOVE: Prairie Meadow Pond in Plano, Texas, was restored in 2019 using the hydraulic method where the silt is sucked out of the pond’s bottom and into geo bags. The muck is then hauled away while clean water is released back into the pond. Natural Resources District Supervisor Kym Hughes said this type of dredging is not as disturbing for the wildlife. (Photo provided by Plano, Texas)

forward, and it is expecting results soon. The city plans to launch another round of testing.

Carlisle said workers also spent hours and hours manually removing 30,000 cubic feet of vegetation from canals and redoing the water features to better channelize the water. All the outfalls have nutrientreducing baffle boxes installed to filter the water before going into the Indian River Lagoon.

Stormwater Treatment Park in Sebastian is a series of interconnected ponds, dams and weirs that provide stormwater surge and treatment while also serving as a wetland habitat. The integrated pest management plan was developed by a subcommittee of members from the natural resources board, three local scientists from the Florida Department of Agriculture and city staff members. Carlisle said the committee held public meetings.

“It was a collaborative effort with a lot of input,” he said, adding the IPM “stresses more organic and more manual mitigation other than chemicals as a first resort to control vegetation.”

For example, the city uses aphids to attack potato vine and released alligator weed flea beetles in the system to control alligator weed.

Carlisle said Sebastian is the only city in Florida to create an integrated pest management program.

“The council wants to make sure our waterways are taken care of. Flood control is the main benefit, and we want to maintain (them) in a smart, educated, balanced approach.”

He noted Park Department Leisure Services Director Brian Benton is working with the city’s environmental specialist on these plans.

In addition, Sebastian has implemented programs for businesses, which offer stormwater credits to add rain barrels, swales, additional retention ponds and impervious parking lots.

Carlisle said he looks forward to continuing to clean up and maintain local waters. “We’ve been pretty proactive.”

In Plano, Texas, having clean water sources to keep wildlife healthy is a priority. Kym Hughes, natural resources district superintendent for the city of Plano, said the city hasn’t experienced a lot of invasive plants in its ponds, but it has been dredging a few because the sediment gets so deep it creates algae blooms and makes the water unfriendly to aquatic life.

The city contracted with American Undercover Services for hydraulic restoration (dredging) of the ponds. The company sent a certified scuba diver to the pond’s bottom with a hose that basically “vacuums” the water, muck and sediment into large geo bags that are 30 feet wide and 100 feet long. The muck and organic matter stay in the bags and are hauled away, while clean water is filtered through and returned to the pond. There are 12 ponds in the Plano park system.

Haggard and Prairie Meadow ponds were restored in 2019, while Shawnee followed in 2020. Hughes said staff monitor sediment levels every three to four years. If necessary, the ponds are put in a rotation to be restored.

Plano also has sediment studies conducted so officials know how much muck there is and how deep it is. Hughes said the city wants some plants to grow for wildlife, but when the sediment gets too deep, it creates an aquatic environment that is not good for wildlife.

According to Hughes, dredging the pond in this manner “doesn’t affect the wildlife as much as other types of dredging.”

Removing all that sediment on the pond bottom “turned out to be helpful — there’s a lot more distance between the surface and the bottom, making it harder for sunlight to penetrate to the bottom where some invasive plants use it to grow.”

She said the city also uses a blue or black aquatic dye to block some sun waves from reaching the bottom. They’ve started documenting the silt levels.

The ponds’ maintenance is contracted out, and they pick up trash in the pond and the surrounding buffer zones, test ph levels and measure the dissolved oxygen levels. They measure the DO levels to ensure the oxygen level is good, which is necessary for the fish. The city also has fountains and aerators in the ponds to help with that.

Signs have been posted stating “don’t mess with wildlife” and “don’t feed ducks and geese,” according to Hughes.

“People are more concerned about the wildlife,” she said, to the point that the city had to build a rock ramp in one pond so turtles could get out since it had concrete sides.

Plano established “conservation buffer zones” around each of the natural edges of ponds and creeks and in naturally occurring wooded A fountain in the middle of Russell Creek Pond in Plano, Texas, helps keep the dissolved oxygen levels in the water to a suitable level for wildlife. (Photo provided by Plano, Texas)

Stormwater overflows at Stormwater Park. (Photo provided by Sebastian, Fla.)

areas to prevent soil erosion caused by heavy rains, severe floods and severe compaction from heavy machinery.

According to the conservation buffer zones document Hughes provided, “This zone slows down erosion because the turf and indigenous foliage are allowed to grow and spread, thus increasing their ability to make food and establish a more extensive and substantial root system. This increases plants’ ability to hold on more tightly to soil particles when flood waters come through.”

Other benefits include trapping sediments, enhancing water infiltration rates, filtering fertilizers and pesticides, promoting fish and wildlife habitats and protecting biodiversity. The plan also states vegetation should not exceed 18 inches at any time, and that ragweed be controlled with frequent inspections. Access lanes may be made where deemed necessary and appropriate for patrons to access the ponds or creeks and signage be placed in those areas.

Hughes said she’s been with the city for 20 years, and the city has “come a long way — we try to be as environmentally friendly as we can.”

The City of Portage, Wis., has developed a lake management plan and an aquatic plant management plant for Silver Lake — an important water resource for the city. (Photo provided by Portage, Wis.)

Portage, Wis., embarks on lake management plan and canal restoration

The city of Portage, Wis., lies between two rivers—the Fox River, which empties into Green Bay and then Lake Michigan, and the Wisconsin River, which empties into the Mississippi River and eventually into the Gulf of Mexico.

Portage also has Silver Lake within the city limits — a 70-acre lake — and last year, officials updated an aquatic plant management and lake management plan. That plan was done with the assistance and cooperation of the University of Wisconsin, Steven’s Point and the Wisconsin State Department of Natural Resources.

City Administrator Shawn Murphy said, “The impetus is to preserve and protect the water quality of the lake overall now and in the future.”

Park and Recreation Manager Toby Monogue said officials held open forums to educate the community.

Murphy said the city enlisted the help of Columbia County Land and Water Conservation to file grants and received $50,000 to conduct a survey and help develop a plan. Monogue added the plan has two parts: lake management and aquatic plant management.

Implementation is ongoing. The plan has recommended the city put in retention basins as well as sump catch basins, which allow for the settling and coagulation of solids, etc.

Murphy said there are some shoreline zoning restrictions like no one can build or have septic systems right up to the water’s edge; however, Monogue noted there should be more shoreline restrictions.

Recommendations for property owners include educating them about why they shouldn’t mow up to the water’s edge in order to leave a buffer to keep phosphorous from running off into the lake. The buffer also deters waterfowl from coming ashore.

“This plan helps residents learn best practices like putting in plants buffer strips or other material to help mitigate runoff and deter wildlife from sitting on lawns,” Monogue said.

The lake has two lobes or basins. One is shallow with naturally occurring aquatic plants, while the other is deeper by the beach and is used for water skiing, boating, etc. Monogue’s department harvests the weeds on the lake, using a cutting map the Department of Natural Resources approved for what can and cannot be cut.

He said seasonal employees harvest the weeds from mid-May through mid-September. “They’re on the lake about three days a week for seven hours a day.”

He reported in 2019, they had removed 320 tons of aquatic plants, and in 2020, they had removed 328 tons. Employees don’t remove every weed; some aquatic plants are needed, so the cutting is primarily to provide boats with better navigation of the waters.

Monogue also worked with the Fish and Wildlife Department on a goose abatement program, and the city received a permit to oil eggs in the geese nests. He reported this is the first year they’ve done this. Workers use 100% corn oil and spray the eggs, which causes them not to hatch. It tricks the geese into sitting on the eggs that will never hatch. Monogue said it takes a couple of years for the program to work because the geese are birds of habit, meaning they return to the nests year after year. After a couple of years of no hatchings, geese will supposedly change sites.

Monogue said a couple of individuals who live on the lake volunteered to oil the eggs, and they found two nests with about 15-18 eggs. There may be more nests in inaccessible areas due to thick cattails.

Restoring a historic canal

The canal in Portage connects the two rivers and was developed in the mid-1800s. It was closed up and abandoned in the early 1950s, leading it to fall into disrepair. The canal was a heavily industrialized site for manufacturing facilities, which discharged runoff into the canal.

“So it’s heavily polluted,” Murphy said.

Since it’s a state waterway, the city partnered with the Wisconsin Department of Natural Resources and the Wisconsin Department of Transportation to clean up the canal. They’ve been dredging out sections of the canal’s bottom, which are polluted with heavy metals and bacteria. Murphy described the muck as looking like chocolate Silver Lake Beach in Portage, Wis., has a beach area that the city has committed to preserve with its lake management plan and aquatic plant management plan. (Photo provided by Portage, Wis.)

Silver Lake in Portage, Wis., has a beach and recreation area that is enjoyed by residents and visitors. (Photo provided by Portage, Wis.)

This is a before photo of the historic canal in Portage, Wis., which shows all the overgrowth and murky water before it was dredged. (Photo provided Portage, Wis.)

This aerial photo of the historic canal in Portage, Wis., shows ongoing dredging operations. The City of Portage has partnered with the state to clean up this canal and make it a recreation destination. (Provided by contractor Entract LLC)

pudding. Once dredged out, the muck is properly disposed of and then capped off with sand cover to dissuade aquatic plant growth. Murphy said Portage put in new sides along the canal and a trail “so it’s a more user-friendly destination.”

The canal is listed on the National Registry of Historic Places with the National Park Services. Portage improved a mile-anda-half section last year, and this year improved another mile, cleaning out trees, plants and garbage.

“It’s been more like a swamp than a river. Cleaning up and reestablishing the channel and flowing water will keep it cleaner,” Murphy said.

Portage has also installed a path with benches and lighting, allowing it to be a recreational destination. It was an expensive endeavor, costing $9 million for the one-mile section, which the city is installing this year. Murphy said the state is picking up $7.2 million of that cost.

The total length of the canal is almost 5 miles, and the city has restored 2.5 miles. There are gates and locks in the canal prohibiting boats from using it to get from one river to another, but canoes and kayaks can access restored areas.

Murphy said, “We’re blessed to have the river within corporate boundaries, but we don’t have a lot of management or control over its use because it’s a state waterway.”

He said the city does own a boat landing, and it monitors the water levels of the river because, after snows and severe storms, the runoff impacts the community. Murphy said officials worked with the Army Corps of Engineers to construct an engineered levee in 2008 to protect the 4 miles of shoreline.

“That effectively removed 400 properties from being located in a flood zone,” he said.

For other municipalities looking to improve their waterways, Murphy said they relied heavily on experts at the University of Wisconsin Steven’s Point Center of Surface Water Education, but he suggested, “Look at the trends — how much phosphorous is in the water now compared to 20 years ago? Are the phosphorous levels creeping up?”

Monogue said the city of Portage is unique in that it doesn’t have a lake management district. “So more fell on the city’s responsibility to do a study and the harvesting.”

Murphy agreed, stating when the city did the survey early on as part of the lake management plan, there was strong support for putting in place features and structures, “but not strong support to create a lake management district to help fund some of those things.”

Murphy suggested city officials “take a step back and see what you currently have and where you are.”

A closer look at Portage’s lake management strategy

Silver Lake in Portage, Wis., is a groundwater drainage lake comprised of two connected basins residing in a kettle pothole, and it’s believed to have been formed 12,000 to 14,000 years ago. Some of the suggestions offered in the lake management plan for improving the lake include: creating fish and wildlife habitats, native plantings, preventing runoff, rock infiltrations for runoff from roofs, rain gardens, etc.

Goals listed in the plan include:

• Water quality that remains below the state’s phosphorous criteria and sufficient dissolved oxygen to support the fisheries; • Have healthy shorelines that protect water quality and provide essential habitat by restoring approximately 1,000 feet of shoreline in the next five years; • All shorelines around Silver Lake will be conducive to limit the geese population on the lake; • Local citizens and lake users will be knowledgeable about the aquatic plant community in Silver Lake and take appropriate action; • Strategies will be implemented to support healthy fisheries in Silver Lake, and when there is a balanced fish community, they’ll know it’s a success; • Recreational opportunities on and near Silver Lake will protect a healthy ecosystem and safety of lake users; • City of Portage will use all available media to inform, educate and advocate for Silver Lake; • And keep the Silver Lake Management Plan updated with current information.