In 2007 and 2008, Upper Hay Lake looked to be degrading. After mid-July in both years, lake clarity dropped 15 feet to an average of less than 4 1/2 feet.
Blue-green algae growth was likely fueled by high concentrations of phosphorus. The state standard for phosphorus for lakes in this ecoregion to be considered impaired, or failing to meet the standard for aquatic recreation, is no more than 30 micrograms per liter.
In September 2007, Upper Hay registered 58 micrograms per liter. In June 2008, it registered 40.
Claire Steen knew something needed to be done to protect the lake and reverse the trend, so she reached out to the Crow Wing Soil and Water Conservation District for help.
In 2014, Steen - president of the Upper Hay Lake Association - applied for and was awarded a Community Partners Grant from the SWCD. Upper Hay proposed to install native vegetative buffers behind coir logs, to protect the shoreline, plus infiltrate and treat runoff. The plan was to intercept the phosphorus before it reached the lake and fed algae production.
With help from the SWCD, seven shoreline buffers were designed and installed that year. Since then, four more have been added for 11 buffers total on the lake, nine of which have been paid for in part with the Community Partners Grant.
"The buffers took some time to establish because just a couple of weeks after we had the first ones installed a big storm hit and damaged much of the vegetation we had planted," Steen said. "But the coir logs held and kept the shorelines from falling apart."
The water level in the lake reached 1,232.41 feet in 2014, a record high level for Upper Hay Lake and roughly a foot above its average. High water levels increase erosion through wave action and can damage shoreline vegetation that otherwise holds the shore soils together.
Lake residents generally approve of the buffers. Steen said some residents have gone over and above by adding to the shoreline restoration project.
"Cindy Rieck, who really believes in the native plant buffers, has done three or four restorations on her shoreline, and Dale Harwell kept records of water levels on his shoreline for many years so that he knew exactly where to plant to ensure that the buffer wouldn't wash out," Steen said. Steen hopes more buffers will be installed in the coming year, but for now, the ones that have been installed seem to have had a positive effect.
During 2016, the Secchi disk reading was just under 6 feet at its peak, and all but that one reading were at 2 meters or greater, with most over 3 meters. Although phosphorus data has not been gathered since 2011, typically the Secchi readings are an effective proxy for phosphorus levels, and the signs in Upper Hay Lake are very good.
For a moderately shallow lake (maximum depth 42 feet) with a significant amount of development, increasing clarity indicates phosphorus runoff and algae production have decreased. However, more needs to be done to maintain the trend, including replacing critical areas of grass lawns with buffers and planting into and behind rock rip rap.
Areas that had vegetation removed many years ago have experienced noticeable erosion of shorelines, and this lost shoreline cannot be regained. However, the implementation of the shoreline buffers helps ensure the losses of the past do not continue into the future.