SOUTH DAKOTA Department of
Environment & Natural Resources

Protecting South Dakota's Tomorrow...Today!
Joe Foss Building
523 E Capitol
Pierre, SD 57501
Field Offices
Contact Us
SubMenu

Watershed Protection

Frequently Asked Questions (FAQs)


What is nonpoint source pollution?
What is a watershed?
What is a TMDL?
What is the water quality of a certain lake or stream?
How do I start a lake improvement project?
What is a water quality assessment?
How much does it cost to complete a lake assessment and a watershed project?
Why is my lake green?

 

What is nonpoint source pollution?

Rainwater and snowmelt washes off the land into streams, lakes and wetlands or seeps into ground water. As this runoff moves across plowed fields, city streets, suburban back yards and other land surfaces, it picks up soil particles, pesticides, fertilizers, animal wastes and other pollutants such as road salt, and crankcase oil. Originating from numerous small sources, pollution from runoff is widespread and dispersed. To distinguish it from "point source pollution" such as a discharge from a factory or city sewer pipe, contaminated runoff is commonly described as "nonpoint source pollution."

Nonpoint source pollution is estimated to account for over half of our nation's water pollution.

 

What is a watershed?

A watershed is an area of land from which all the water drains to the same place. The final destination could be a stream, pond, lake, or wetland. A watershed can be large or small depending on goals of individual projects.

Top of page

 

What is a Total Maximum Daily Load (TMDL)?

A Total Maximum Daily Load, or TMDL, is an important tool for the management of water quality. The goal of a TMDL is to ensure that waters of the state attain water quality standards and provide designated beneficial uses. A TMDL is defined as "the sum of the individual waste load allocations for point sources and load allocations for both nonpoint source and natural background sources established at a level necessary to achieve compliance with applicable surface water quality standards." In simple terms, a TMDL is the amount of pollution that a water body can receive and still maintain water quality standards and beneficial uses. TMDLs are required on waters that do not attain water quality standards or assigned beneficial uses.

Access South Dakota's TMDL webpage for more information on DENR TMDL activities or the US Environmental Protectection Agency TMDL webpage.

 

What is the water quality of a certain lake or stream?

The department monitors several lakes and streams and may have data available on the waterbody that you are interested in. If there is no data, perhaps a volunteer monitoring project could be initiated. Please follow the link below if you are interested in more information on these topics:

    Citizen's Water Quality Monitoring Program (exit SD DENR)

Top of page

 

How do I start a lake improvement project?

The first thing is to get your neighbors concerned over the issue of water quality and how it affects them. A water quality improvement project can only be successful if the local community is committed to improving water quality. This will mean that many of the identified restoration practices will require cooperation at every level, from government to private landowners within the watershed. The information and education aspect is an important part of the process. You will also want to contact the department or other agencies like your local conservation district or water development district offices and ask for help. The department works in partnership with local groups under a voluntary, cost-share approach. This approach has resulted in greatly improved water quality in many successful improvement projects. Look at examples of final reports from a few of the most recent 319 projects.

 

What is a water quality assessment?

An assessment, or evaluation of the problem, is an essential part of any lake or watershed restoration project. A thorough assessment documents problems and identifies the feasibility of possible solutions.

Top of page

 

How much does it cost for a lake assessment & watershed project?

A two year lake assessment typically costs from $80,000 to $120,000. The dollar amount depends on the size of the watershed and the number of samples which will need to be collected. If the assessment is funded under the EPA 319 Nonpoint Source Program, 60% of the total amount is typically funded by federal dollars. The typical local share of the 319 project is 40%. The state does not have general funds set aside for assistance for watershed assessment funding. A watershed project can vary depending on the amount of work identified to be implemented. Project expenditures can range between $100,000 to over a $1,000,0000. Funding packages and time tables are negotiated after the assessment and the scope of work has been defined. Many watershed implementation projects may last well over 5 years. Information is available on 319 funding and other state funding sources.

 

Why is my lake green?

The green color of most lakes is caused by an excessive concentration of algae. Algae will become very abundant under certain conditions. This is a very common questions asked by lakeside residents and recreational users. The color of lakes and ponds is often caused by large numbers of microscopic plants called algae. These one-celled organisms grow profusely during spring and summer when fertilized by excessive amounts of nutrients (nitrogen and phosphorus) that enter lakes from the surrounding countryside, transported by rainstorm and snowmelt runoff. The tiny plants that live suspended in the water column of lakes are known as phytoplankton. The are passively carried by the turbulence or movement of the water. When present in high numbers, the algae clumps together. This condition is referred to as a an algal bloom. These blooms are considered a nuisance in lakes used for drinking water and recreation.

There are several groups of phytoplankton that included diatoms, green algae and blue-green algae. Diatoms and green algae are slightly heavier than water and rely on water current to keep suspended in the water. Some blue-green algae though have the ability to adjust their buoyancy. This means they can sink or rise in the water column as light conditions and nutrients change. Some blue-green blooms are considered toxic and can cause great harm to the lake and animals that drink from the lake during the blooms. Diatom blooms can color lake waters brown. This is because diatoms contain brown-colored pigments that mask the green color of the chlorophyll.

The term algae bloom is most often applied to describe summer growths of planktonic blue-green algae which may be compromised of circular groups of round cells or clumps of filament. The algal pigment phycocyanin that is found in blue-greens is water-soluble. The disintegration of a bloom will release this pigment into the water will color the water temporarily with an intense blue-green or green color. A drastic reduction of the supply of nutrients from the lake’s watershed is often the only way to eliminate or even significantly reduce the problems caused by massive algal blooms.

Top of page

 

4oiGIFNEIEJJVCBEZXRlY3Rpb24=