Water Quality Monitoring

Recent Data

The State of Michigan monitors phosphorus and other water quality indicators in Lake Macatawa and selected streams every other year. This helps measure progress toward improving Lake Macatawa’s water quality. The most recent report from the State is the 2012 report. They are still processing 2014, 2016, 2018, and 2020 reports and we will post them to our website when available.

2015 Biological Survey (fish and bugs)
2015 Bacterial Sampling (statewide) – Includes 3 sites in the Macatawa Watershed

The GVSU Annis Water Resources Institute (AWRI) has also been monitoring Lake Macatawa and selected streams. Project Clarity is financially supporting this effort and we will use the data to gauge the overall health of Lake Macatawa and the impact of Project Clarity restorations.

2022 AWRI report           2022 AWRI dashboard
2021 AWRI report            2021 AWRI dashboard
2020 AWRI report           2020 AWRI dashboard
2019 AWRI report            2019 AWRI dashboard
2018 AWRI report            2018 AWRI dashboard
2017 AWRI report            2017 AWRI dashboard
2016 AWRI report            2016 AWRI dashboard
2015 AWRI report            2015 AWRI dashboard
2014 AWRI report

Hope College, through the Global Water Research Institute (GWRI), also conducts water quality monitoring in the watershed in support of Project Clarity.

2020-2021 GWRI annual report

Aquatic Macroinvertebrates

Aquatic macroinvertebrates are aquatic critters that do not have a backbone that we can see with our naked eye. They include insects, crustaceans, clams, mussels, and snails. They vary in shape and size, but all live in the water for at least a portion of their life cycle. Their survival depends on clean water. They are a crucial food source for fish, which makes them an important part of the aquatic ecosystem. Different types of water critters have varying sensitivities to water pollution. We look at the abundance and types of macroinvertebrates in a stream to get a general idea of the stream’s health. Most water critters live in the stream bottom among rocks, under logs or in leaf packs, making them relatively easy to collect with a net. It’s also inexpensive to collect and process water critters and is easily done with the help of volunteers.

The MACC partners with the ODC Network to monitor macroinvertebrates populations at 7 locations in the Macatawa Watershed twice a year. The monitoring program started in the Fall of 2012 and we intend to continue well into the future. Contact Kelly at kelly@outdoordiscovery.org if you are interested in helping with this effort and we will add you to our volunteer list. Below is a summary of the data collected from the fall of 2012 through the spring of 2021:

It is too soon to draw conclusions from the data since it represents a short time period. What we can see is variability at a site over time and across sites for any given event. Some of this is natural due to seasonality (sampling occurs in spring and fall to capture different species during life cycle stages), weather conditions or streamflow.

As of the fall of 2021, we are following a new scoring procedure developed by MiCorps. Based on the differences between the new and old system of scoring, we won’t be able to compare the new data to the old. Therefore, we’ll essentially start over with a new dataset beginning in the fall of 2021.

We follow a Quality Assurance Project Plan to ensure the integrity of the data collected.

Volunteer Secchi Disk Monitoring

Several volunteers collect water transparency data at designated locations in the watershed once a week during the open water season. The measure transparency using a Secchi disk, an 8-inch, circular, black and white metal plate attached to a marked rope. The volunteer lowers the disk into the water until it is no longer visible and notes the depth from the markings on the rope. The disk is then lowered a little further and then raised back up until it is just visible. The volunteer averages the second depth reading with the first, and records the final number on a data sheet.

This measure estimates the clarity of the water. Water transparency is a quick and easy measurement that tells scientists a lot about a lake’s water quality. First, it indicates the amount of light penetration into a lake. Second, Secchi transparency provides an indirect measure of the amount of suspended material in the water. Changes in transparency over time can be an important indicator that a change in water quality is occurring.

Secchi disk measurements provide objective means to evaluate water clarity versus subjective statements such as “It is clear,” or “It is muddy.” One person’s clear water may be another person’s muddy water.

We are always looking for additional volunteers! Contact the MACC to learn more about becoming a part of the volunteer monitoring program.

Click here to see the MACC’s Secchi data through 2013 that is collected at 4 locations weekly throughout the spring and summer months by our local volunteers.

The graph below summarizes the annual average Secchi depth from 2002 through 2018 at four locations in Lake Macatawa. The overall trend seems to indicate that the Secchi depth is decreasing, meaning that the clarity of the lake is decreasing. Increasing Secchi depth would indicate improved water clarity.

Paw Paw = the Macatawa River accessed at Paw Paw Park
Dunton = Lake Macatawa accessed at Dunton Park
Al’s Dock = private dock, readings stopped in 2015
Channel = Channel to Lake Michigan accessed from the Holland State Park