Rivers and Streams

River and stream rehabilitation and improvement projects done by Aquatic Alternatives have encompassed a wide range of morphological stream types. Each one is unique and yet all have a few things in common:

1. A stream or river is dynamic. Seasonal changes in flows can be extreme, as can temperature changes, chemical characteristics and productivity potential.
2. Stream channels are not stationary fixtures. They like to move unless confined by geologic features.
3. Most importantly, while streams and rivers may provide a home for trout and other aquatic wildlife, they are primarily a means of conveying surface water and sediment to the lowest point possible.

Aquatic Alternatives approaches all projects with this in mind: no stream or river has a steady state only a changing succession of extremes. This is perhaps less true of regulated streams and rivers with heavy human impact, but when planning a stream improvement project the basic idea holds true. Plan for the extremes.

1. Aquatic Alternatives has spent years developing habitat improvement structures that utilize the energy of flowing water to promote different life stages of trout.
   • Providing protected habitats is sometimes not enough.
   • Forage of appropriate size also needs to be readily available in such quantities as to improve recruitment and promote growth.
   • Natural separation of age classes is important as well as a diversity of species and sizes of aquatic invertebrates.
   • Habitat for fish and forage is vital to creating an improved fishery.
2. In many instances the extreme is a lack of flowing water due to upstream use or prolonged drought conditions. The habitats of both fish and invertebrates can be devastated.
   • Aquatic Alternatives addresses this in several ways including deep water holding areas or access to impounded waters in lakes or ponds.
   • Equally important is the development of working water cycles in upland areas and water storage in aquifers.
   • Improving water cycles is often best addressed with the use of grazing animals managed with soil improvement in mind.
   • Local aquifers can be managed to some extent with irrigation techniques and pond development in porous soils near riparian areas.
3. Stream bank stability is important when doing a stream improvement program. Destruction of property and aquatic habitats are the obvious results of degraded bank conditions.
   • Maintaining or creating floodplains with appropriate wetland vegetation types can greatly reduce the impacts of flood stage events.
   • In areas where stream energy is directed at soft banks and erosion is occurring, even with minimal flows, bank protection structures can be built.
   • We utilize the stream energy to produce excellent habitats for aquatic invertebrates. Narrowing of channels can aid in transport of sediment loads past critical areas.
4. Once the initial limiting factors governing a stream improvement project are addressed, building a functional trout habitat comes next. Aquatic Alternatives has developed several means of trapping coarse organic particulate (CPOE) to provide the nutrient base to drive a successful food chain. This nutrient base is further refined so that organisms best suited to provide the right kind of forage for differing age classes of fish are in close proximity to the best protected habitats for that age and size of fish. As trout grow we provide means for them to move into protected habitats better suited to their size and forage that promotes more efficient growth. In many streams and rivers there is an abundance of forage available but capturing and digesting it requires as many or more calories than are gained. The result is a fish that gets to a certain size and then stops growing. Providing forage large enough to promote growth is critically important.
5. Building a wild sustainable population of trout can only occur if there is successful spawning and development of eggs to hatching stage. Aquatic Alternatives has been using and refining spawning channels in their research hatchery for years and has developed several methods of improving and building spawning areas. We address the following factors, plus others, when designing a stream habitat improvement project:
   • The behavior of spawning adults;
   • The temperature of the water;
   • The proximity of protected adult habitat(s);
   • The emergence of fry.
6. Aquatic Alternatives is very concerned with the aesthetics of our projects. Function and form go hand- in-hand, and a well-designed project will look like it has always been there. We are careful not to disturb banks or destroy vegetation when working on a stream project. Naturally occurring materials are used as much as possible and when specific man-made materials are used we strive to make them blend into the background.

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