In Ohio, wetlands have become a key tool to improve water quality thanks to the state’s H2Ohio Initiative, which provides grants for wetland restoration and enhancement projects. Wetlands act like nature’s filters, holding onto excess nutrients like phosphorus and nitrogen that fuel harmful algal blooms, and H2Ohio has funded hundreds of wetland projects across Ohio since 2020.

But how do we know that the wetlands are actually working?

That’s where the H2Ohio Wetland Monitoring Program comes in. Through the Lake Erie and Aquatic Research Network (LEARN), contracted by the Ohio Department of Natural Resources (ODNR) and maintained by Ohio Sea Grant, the program assesses how effective H2Ohio wetlands are at removing nutrients. So far, results suggest that most of the wetlands studied are indeed filtering and retaining phosphorus and nitrogen.

“The impacts go even deeper,” said Olivia Schloegel, research coordinator for the Wetland Monitoring Program. “Monitoring these wetlands in partnership with the people who build and manage them is kind of creating this shared sense of trust and investment in natural infrastructure found in the environment.”

In 2020, when Gov. Mike DeWine’s H2Ohio Initiative began, ODNR enlisted the Ohio-based regional research consortium LEARN to develop and implement a monitoring program, designed to improve future wetland design and management. The Wetland Monitoring Program became the first initiative from LEARN, a network of researchers from more than 20 universities in Ohio and surrounding areas studying aquatic science.

Since then, the monitoring program has studied 45 of the more than 200 completed H2Ohio wetland projects, with researchers assessing the nutrients flowing into and out of the wetlands, focusing on overall retention. Notably, all projects with sufficient data showed effective reductions in phosphorus and nitrogen, the primary drivers of harmful algal blooms. Wetlands retained between .2 to 29 pounds of phosphorus per acre and as much as 863 pounds of nitrogen per acre.

“The interface among all the partners is my favorite part about the whole program. … Over time, we’ve built a lot of trust among managers, policymakers, practitioners, and researchers in a way that I don’t think would have been possible if we weren’t all working together.”
Olivia Schloegel, H2Ohio Wetland Monitoring Program

“We study what’s actually happening in the wetlands, calculating nutrient budgets to assess if wetlands are retaining nutrients,” Schloegel said. “But because we’re science-based and multidisciplinary, we’re able to get to the ‘how’ and ‘why’ of what drives nutrient function in wetlands. We’re also increasingly realizing wetland managers want to know what to include in wetlands: what features, what plants, when to connect the water, and so on.”

The Wetland Monitoring Program is unique in that it exclusively studies removal of nitrogen and phosphorus as a function of wetlands. Very few other monitoring programs study a diverse system of both restored and constructed wetlands in this way, said Lauren Kinsman-Costello, a Kent State University professor who serves as research lead for the H2Ohio Wetland Monitoring Program. The group employs a tiered approach, intensely studying a handful of representative H2Ohio wetland projects while conducting lower-intensity monitoring on others.

“Prior to this program, most of the existing methods for monitoring wetlands on a really large scale were driven from a habitat quality perspective, focusing on ecosystem health,” Kinsman-Costello said. “That’s very different from a targeted assessment of the effectiveness of wetlands at removing nutrients.”

The program’s monitored projects include a diverse range of wetland projects with different monitoring approaches. One is the Magee Marsh/Turtle Creek Bay Wetland Reconnection, a 148-acre coastal wetland in Ottawa County. Another is the Forder Bridge Floodplain Reconnection, a former agricultural field in the Maumee River watershed that now includes a series of wetland pools constructed in 2021.

At Redhorse Bend Preserve Wetland Restoration near Fremont, Ohio, researchers use sensors and regular sampling to study the flow of water on 28 acres of wetland along the Sandusky River. Meanwhile, at the Tipp City Off-Channel Wetland located near Dayton, Ohio, the team studies its capacity to store nutrient loading from the Great Miami River. The program also assesses the Burntwood-Langenkamp Wetland Conservation Area, a former corn and soybean field that now has 45 wetland acres, 35 prairie acres, and 10 acres of forest in Mercer County.

From these and other monitored projects, the team is gaining insights into how to design and manage wetlands. For example, projects with features such as water-level control structures or pumps can have more targeted nutrient interception, and there are native plants (e.g., broadleaf arrowhead, soft rush) that may promote nutrient retention and enhance biodiversity.

“The unique partnership that we formed with the LEARN H2Ohio Wetland Monitoring Program has been critical to improving our prioritization and design of new H2Ohio wetland restorations, tracking our progress, and even revisiting our completed projects to improve their performance,” said Eric Saas, H2Ohio Wetlands Program Manager at ODNR.

The program’s monitoring has been informed by on-the-ground expertise, engaging over 30 partners, including universities, county parks, land conservancies, community groups, and private landowners.

“The interface among all the partners is my favorite part about the whole program,” Schloegel said. “Creating this shared vocabulary around wetland nutrient function and understanding what really matters to these different partners is one of the greatest opportunities I’ve ever seen.”

“Over time, we’ve built a lot of trust among managers, policymakers, practitioners, and researchers in a way that I don’t think would have been possible if we weren’t all working together,” she continued.

For one partner, the Stream + Wetlands Foundation, the Wetland Monitoring Program has provided valuable feedback on the H2Ohio projects it implemented, including the ODNR Trumbull Creek Wetlands Restoration Project in Ashtabula County.

“It’s tremendously valuable to have a well-structured and rigorous research program that evaluates the performance and dynamics of wetlands and communicates those findings to partners,” said Greg Snowden, senior biologist at the foundation.

“The Stream + Wetlands Foundation is about to begin construction on our third H2Ohio-funded project, and we have gained valuable insight into design, planting, and data collection through our conversations and interactions with the Wetland Monitoring Program,” said Chelsea Keefer, strategic partnerships lead. “The team is passionate and hardworking, and the work they do has real consequences in the world of ecological restoration.”

Another wetland practitioner, MAD Scientist Associates, has been heavily involved in the design and construction of numerous H2Ohio wetlands since the program began. Mark Dilley, chief scientist at MAD, said the program’s efforts to both fund and monitor wetland restorations make it one of a kind.

“As wetland restoration professionals who are looking to continuously improve the performance of our wetlands, my team and I consider these efforts by our academic and research colleagues within the Wetland Monitoring Program to be of tremendous importance, benefitting our design and planning practice and informing our future successes in the wetland restoration field,” Dilley said.

In addition, the program has monitored at least seven of the Black Swamp Conservancy’s H2Ohio wetland projects, said conservation biologist Melanie Coulter. She praised the team’s coordination, consistently monitoring a large number of wetlands with a diverse team of researchers from several institutions.

“The data generated and analyzed by the program has concretely improved the nutrient reduction capacity of the Conservancy’s wetland restoration projects, adding new site assessments to our planning process, informing the water input considerations in our wetland designs, and influencing our long-term maintenance of the wetlands,” Coulter said.

Moving forward, it’s essential for the Wetland Monitoring Program to continue to study the state’s wetlands to provide long-term data and ensure effectiveness over time. Data from the first few years of a new wetland’s construction can change as plant communities establish, soil adapts, and abnormal weather occurs, so regular monitoring is needed.

“People will and have seen improved water quality because of these wetlands, but the wetlands are changing and are located in changing landscapes,” Schloegel said. “So we have to keep monitoring them too.”

To learn more about the H2Ohio Wetland Monitoring Program, visit LEARN’s website or read the program’s latest annual report. A new annual report is expected in August 2026.

Ohio Sea Grant is supported by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) School of Environment and Natural Resources, Ohio State University Extension, and NOAA Sea Grant, a network of 34 Sea Grant programs nation-wide dedicated to the protection and sustainable use of marine and Great Lakes resources. Stone Laboratory is Ohio State’s island campus on Lake Erie and is the research, education, and outreach facility of Ohio Sea Grant and part of CFAES School of Environment and Natural Resources.