SIOUX FALLS, S.D. (KELO) — Are you dipping your toes or taking your watercraft into dirty water in South Dakota this season?

A high percentage of the state’s rivers and streams are impaired but the majority of lakes and reservoirs appear to be in good shape, according to the 2022 South Dakota Integrated Report for Surface Water Quality Assessment from the South Dakota Department of Agriculture and Natural Resources (DANR).

Seventy-eight percent of South Dakota’s rivers and streams are impaired, according to the 2022 DANR water quality report. Eighty-four of 176 assessed lakes and reservoirs are on the impaired water bodies list, according to the DANR.

The state has 584 lakes and reservoirs designated with beneficial uses such as fishing and swimming.

An impaired body of water means it does not meet water quality standards for activities such as immersion in the water or that fish have tested for high levels of mercury. A stream or river may have elevated levels of E. coli or elevated levels of total suspended solids (TSS) such as sediment.

Water quality is not a real issue for lakes and reservoirs in the state, said Brian Walsh, director of public affairs for the DANR.

That is generally true, said Barry Berg of the Big Sioux River Project, an organization that works with water quality projects in the Big Sioux River Watershed.

The Big Sioux River Project tests water at several sites in the watershed, Berg said. So while it doesn’t test lakes and reservoirs, Berg said, that in general those water bodies may occasionally get high levels of E. coli, such as Lake Alvin but if there is any impairment, it can be if sediments at the bottom can be stirred and algae start to bloom.

Organizations such as the Big Sioux River Project (BSRP) and the Friends of the Big Sioux River, another organization that advocates for water quality on the river, test the water within the Big Sioux watershed. The DANR also tests the water across the state.

“Statewide, we have a water quality monitoring network of well over 150 sample sites across the state. We sample those monthly or quarterly, year-round,” DANR environmental scientist Aaron Leingang said.

The DANR has a water quality monitoring portal on its website which shows the results of testing. The state’s Game, Fish and Parks (GFP) department also tests the water.

“Through the summer, GFP will do testing on these water bodies to ensure individuals are safe when enjoying these activities,” GFP spokesman Nick Harrington said in an email to KELOLAND News.

If a lake, Lake Alvin, for example, needs to close the swimming beach because of high E. coli levels, the GFP will issue the advisory.

Wall Lake is a popular recreational lake in Minnehaha County. Data from the DANR water quality portal shows that the lake had single-digit to a high of roughly 15 parts per milliliters of E. coli during the prime swimming season from June through August from 2018 through 2022. Those are very low levels of E. coli.

The phosphorous level on Aug. 16, 2022, was .315 mg/l on Wall Lake. According to Lehigh University, the phosphorous level of a lake should not be higher than 0.025 mg/l. However, a reading of 1.0 mg/L is considered excellent. Of the recorded phosphorous data on Wall Lake from 2020 through 2022 many were above 0.189.

Part of the data that the DANR shares for bodies of water on the water quality monitoring portal.

The Michigan Department of Environment, Great Lakes and Energy requires 300 E. coli per 100 milliliters for the water to be considered safe for swimming.

The Clean Water Alliance in Wisconsin lists 235 E. coli per 100ml has a low threshold.

On Sept. 30, 2020, the E. coli reached a level of 1050 per 100ml at Wall Lake, according to the DANR site.

The E. coli level at Lake Cochrane was 6.5 per 100ml on July 5, 2022. It was 18.6 on May 22, according to the DANR site. Those were among some of the highest since 2018.

A monitoring site on the Big Sioux River south of Sioux Falls recorded an E. coli level of 13000 on July 7, 2022 but on July 14 it was 122 and 389.

Heavy rains and other factors can increase levels of E. coli and other pollutants.

Where do the impairments come from?

Chemicals such as nitrogen and phosphorous can support the growth of algae and other plants in a water body but too much can cause too many plants to grow. Too much algae can reduce oxygen levels and kill fish and harm other aquatic life.

High levels of E. coli can cause intestinal issues and other harm to humans.

Leingang said the DANR collects E. coli samples from May to September.

Impairments come from non-point sources from nature or human activity such as the use of pesticides, fertilizer, road salt or the grazing of livestock or feedlots which can release animal waste into the water.

Source point pollutants are those that come directly from a pipe.

Leingang said the state’s monitoring program provides water quality trends around the state. It can show areas that need attention, he said. The DANR has programs such as the riparian buffer initiative program (RBI) that can help with water quality.

Buffer strips can help stop the pollutants

A buffer strip program provides incentives for landowners to take cropland out of production or remove pasture land from grazing for a certain period of time. Landowners are paid to try and help improve the water quality in the watershed.

The incentive payment for RBI is 250% of the USDA “Pasture or Non-Irrigated Cropland Cash Rent Paid Per Acre for South Dakota,” according to a DANR fact sheet. The fact sheet said the rental rates will vary by location but listed the cropland rent as $350 to $575 per acre and pasture land at $100 to $157.50 per acre.

“A buffer strip can help with any body of water,” said Travis Entenman, the executive director of the Friends of the Big Sioux River.

“You’re trying to filter out the pollutants before they reach the water body,” said Tanner Clausen of the DANR.

Berg has seen the impact of buffer strips on Skunk Creek in the Big Sioux Watershed. Skunk Creek drains into the Big Sioux River near Sioux Falls.

The creek was on the list of impaired water because of total suspended solids (TSS) in 2012, Berg said.

The BSRP started seasonal riparian buffer strip projects along the creek in 2014. By 2016, Skunk Creek was removed from the impaired list as the TSS level had improved, Berg said.

The state and federal governments have several buffer strip or vegetation programs focused on improving water quality.

The DANR’s RBI program is an example of how the department is trying to improve water quality in the Big Sioux River and the watershed. It’s a newer program that has yet to gain substantial footing.

So far, 28 acres have been enrolled in the RBI, Clausen said.

“The program is actually pretty new in itself,” said Clausen. The program was developed in 2021.

Like other buffer strip programs, landowners are paid so much per acre to establish a buffer along the water.

The buffer in crop or pasture land must be a minimum of 50 feet from the ordinary high water mark and a maximum width of 120 feet. Four to six inches of vegetation height at all times.

Walsh said the 2022 state Legislature provided money to the RBI to help fund it and $3 million will be directed to the Big Sioux River Watershed.

If an RBI is established on cropland, no crops are planted in the buffer area. With pasture or cropland, the landowner cannot mow the vegetation for hay from May 1 through Aug. 1.

Cattle can be grazed in the RBI from Oct. 1 through April 30, but there must be an alternative source of water.

Clausen said the cropland near a body of water can often be marginal land. With an RBI, the producers can reduce fertilizer, fuel and other input costs because they are not farming the land.

Berg said one obstacle to landowners using buffer strips is that much of eastern South Dakota, for example, is row crop farming and there is not a lot of pasture or grazing land. Buffers often have restrictions on grazing.

But, a seasonal buffer program used by the BSRP allows for cutting or mowing the vegetation for livestock hay. The buffer is still maintained but the livestock stay off the buffer and can’t reach the nearby water, Berg said. The livestock will not discharge waste into the water, he said.

The BSRP’s seasonal buffer program has an incentive structure that depends on where the land is located. The city of Sioux Falls provides some funding for the BSRP and it’s the epicenter of the watershed region covered by BSRP, Berg said. Incentives are based on how close the land is to Sioux Falls, Berg said.

Land within 25 miles would be paid $140 per acre. The program would pay $120 per acre for land within 26 to 50 miles of Sioux Falls, Berg said. The program would pay $100 per acre for land 51 to 75 miles from Sioux Falls.

The BSRP’s focus is south from Estelline to Sioux City, Iowa. Berg said the incentives decrease as the distance from Sioux Falls decreases. For example, it would be difficult for E. coli from the Estelline area to make it all the way to Sioux Falls, he said.