Save Our Lakes

February 2, 2009 by  

By Doug Leier

Lakes and reservoirs in North Dakota are like a trusty shotgun – when you find one you like, it stands to reason you’ll make every effort to keep it working as long as possible. But you also understand there may come a time when the gun just might not perform like it did in its prime.

That is becoming the case with a number of North Dakota lakes. Many of those experiencing a gradual reduction in productivity are a collection of reservoirs created during the 1950s, ‘60s and ‘70s in all parts of North Dakota. These bodies of water “age” on a different time table than their natural-lake counterparts that have existed since the last glacier

Algae bloom lakes show obvious signs of troubles

Algae bloom lakes show obvious signs of troubles

departed.

Some of North Dakota’s reservoirs were designed for flood control, others for water supply, and a few purely for recreational purposes. Some are large, like Lake Sakakawea, Lake Oahe, Lake Ashtabula, Heart Butte Reservoir and others established on the state’s major rivers. Most are much smaller, created by blocking a small river, creek or stream in the watershed of a larger river. Popular names include the likes of Lake LaMoure, Homme Dam, Northgate Dam, Indian Creek Dam, Sweet Briar Dam and Dead Colt Creek.

Think of your favorite North Dakota fishing holes and odds are your short list will be peppered with manmade lakes. Most of us who fish have ventured to one or more of these smaller waters because of at least periodic, if not consistent, good fishing, plus other forms of outdoor recreation like boating or camping.
 
Several years ago, the Game and Fish Department developed a program called Save Our Lakes, which is designed to help slow or reverse the aging of some of these more popular and productive prairie reservoirs.

All bodies of water, regardless of their origin, face challenges including pollution, watershed erosion and shoreline development. Reservoirs, however, age at an accelerated rate because they are not a natural part of the environment.

One major problem is siltation. The stream feeding your favorite fishing hole is carrying what’s referred to as a

Sediment holding ponds such as this one off of Cottonwood Creek flowing into Lake LaMoure can drastically improve water quality conditions

Sediment holding ponds such as this one off of Cottonwood Creek flowing into Lake LaMoure can drastically improve water quality conditions

sediment load, or small particles of soil suspended in the water as it flows downstream. The hydrology of moving water is then adjusted by the dam that created the reservoir. At some point, the water stops flowing and the suspended dirt slowly sinks to the bottom.

In some small reservoirs, Game and Fish biologists have documented accumulated silt more than 10 feet deep. That’s a significant portion of the original water volume and can create problems with water temperatures that are too high in summer, water not deep enough in winter, and simply less habitat for fish.

While this subject may not be mainstream discussion at coffee shops and gas stations, the Save Our Lakes program is working to address critical issues in lakes and reservoirs across the state.

The innovative program is designed to work directly on lakes – mostly within smaller watersheds – to either remove silt, reduce erosion in the watershed that creates excessive siltation, improve water quality, or stabilize shorelines. Most projects are cooperative efforts between state and local agencies and private landowners.

Some of the specific projects include:

Upstream water holding ponds called sediment dams, which allow silt to filter out before reaching the reservoir basin. These miniature dams also spread water out over vegetation, which removes some nutrients that might stimulate algae blooms, which can hurt fish and limit water recreation.

Bank stabilization projects that address shoreline erosion directly, through various mechanisms such as rip-rapping, reducing bank grade and improving vegetation cover on the bank.

While it may seem that siltation or the life span of a dam is most easily addressed by dredging and removing the silt, this is a costly process that also requires drawing down the water in the lake, which could hurt the fishery in the short term. Dredging is one of the tools, but without complementary projects to reduce siltation in the future, the problem will just start over again.

In a state such as North Dakota it is a constant battle to maintain and improve our water quality for fishing, recreation and consumption. The Save Our Lakes program can’t promise to fix and repair every lake and problem, but it is making headway and working toward addressing some of the worst situations.


Comments

Tell us what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!





Human Verification: In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


*