Herald and Journal, Dec. 23, 2002
Phosphorus 'skyrocketed' in area lakes following June flooding
By Lynda Jensen
Phosphorus levels in many local lakes shot up following historic flooding last June.
"The water influx came from everywhere," commented Brad Wozney of the Wright County Soil and Water Conservation Department.
The higher phosphorus was recorded in nearly every lake, he said. "It just skyrocketed."
For shallow lakes, the higher phosphorus is causing more problems than deeper ones, Wozney said.
However, phosphorus does not affect the health of fish, he added.
Paul Diedrich of the DNR agreed, saying that high phosphorus does not injure local fish, with the exception of the lake kill at Lake Ann.
Lake Ann's fish kill was attributed to shallow standing water being washed back into the lake, as well as heavy infiltration of runoff in Ditch 10, loaded with agricultural waste, Hammer said.
The standing water was depleted of its oxygen because it stood over dying vegetation and farm runoff, which sucked out its oxygen, Wozney said.
County officials suspect that this occurred in most the county lakes, he said.
How well each lake handled the phosphorus depends on its watershed and physical characteristics, Wozney said.
Shallow lakes are less able to handle the influx. However, deeper lakes, which have the sediment settle at the bottom in a cooler layer, tend to keep the phosphorus on the lake's floor, he said. This is a good thing, Wozney said.
Lake Ann's watershed comes from a huge area of 21,128 acres, Wozney said. Comparatively, Howard Lake's watershed is only 4,058 acres.
The total impact of the flood is yet to be felt, Wozney said. However, he pointed out the flooding was something for the record books.
"There's just no way we could have prepared for that," he said.
There are several sources of phosphorus, both urban and rural.
Manure and commercial fertilizer account for phosphorus in agricultural runoff, he said.
He noted that there aren't many cattle ranchers in this area, compared to the past. "There are more corn and soybeans," he said.
Other sources of phosphorus include:
· runoff from residential property carrying grass clippings, leaves and excess fertilizer.
· failing or non- compliant septic systems
· pet waste.
· storm water runoff from impervious surfaces (parking lots, driveways).
· runoff and eroded sediment from agricultural land.
· re suspended sediment from lake bottom usually power boating, but also the flooding caused the water to churn up sediment.
· ash from lakeside fire pits.
· runoff from poorly operated or improperly situated feedlots.
The legislature recently passed laws that limit the use of phosphorus on lawns, although there are some loopholes, such as new lawns and golf courses, Hammer said.
To complicate matters, the soil in Wright County is naturally high in phosphorus, Wozney said.
Higher phosphorus means greener lakes suffering from algae problems, Wozney said.
Wright County has been proactively testing the lakes
Even before the floods, Wright County initiated a lakes monitoring program more than a year ago, said lake association member Tom Hammer.
In fact, there are a number of programs that Wright County is involved in related to area lakes.
In contrast, the state, including the DNR, has done no testing since the flood when the Department of Health tested three different areas of Howard Lake during the actual flooding, with the exception of Lake Ann when it suffered a fish kill.
County testing includes monthly testing of water on area lakes done by lake association volunteers, he said.
The water was tested for phosphorus and chlorophyll (algae). The water samples are taken to a lab in Detroit Lakes, Hammer said.
Volunteers collected water samples and took Secchi disk readings, which measures the water clarity.
Secchi disk readings require the tester to dangle a white circular (Secchi) disk into the lake and then record the depth it can no longer be seen.
Unfortunately, the program may be on the county's chopping block, Hammer said.
Half of the program is funded through the county and the other half by a grant from the state, he said.
This grant, covering 13 of the 22 lakes in the area, expires in the summer of 2003.
Another program is the Healthy Lakes program, which Howard Lake and Lake Ann were just recently selected to be included in, along with six other lakes, lake association member Curt Forst said.
This will collect comprehensive information about the lakes and help solve the quality problems, Forst said.
"Don't get discouraged," Forst said, saying that many residents who care about the lake are making a difference such as sweeping their grass clippings to cut down on phosphorus.
Of course, come spring, it will be as important as ever for people to pay attention to what they are contributing to the lake in the form of runoff, he said.
In relation to storm water, the county is also currently undertaking a study of its culvert system, said Wright County Commissioner Dick Mattson.
Townships were given maps and asked to measure the culverts. These results were to be turned in by Dec. 1, but this date passed, Mattson said.
From there, the county plans to give the results to hydrologists, which will study the situation and determine if any changes need to be made.
This is based on a plan done by Rosseau, which was heavily flooded before Waverly was, Mattson said.
Clouding the waters
Local outdoorsman Jim Wackler noticed a definite change in clarity for local lakes, he said, such as Emma, Howard Lake, and the two Waverly lakes being very cloudy. It depends on the watershed for each lake, he said.
Howard Lake was cloudy last year as well, and actually had an algae bloom worse the year before summer flooding, Forst noted.
Cloudy water doesn't necessarily mean the water is poor, Diedrich said.
Winsted Lake remains clear, Wackler commented.
The path of water
The local watershed has an interesting path in the area.
For example, water travels from Lake Mary to Lake Ann, then Emma into Twelve Mile Creek.
Howard Lake's chain follows this path: Howard Lake to Mallard Pass, then Dutch Lake, ending up in Twelve Mile Creek.
Twelve Mile Creek flows into Little Waverly Lake.
Big Waverly Lake also empties into Little Waverly Lake, although last year the flow was reversed from the excessive waters, which caused Little Waverly to backflow into Big Waverly, Wozney said.
This is bad because Little Waverly's water quality is poor, Wozney said. "Little Waverly has terrible water quality."
Howard Lake-Waverly Herald & Winsted-Lester Prairie