In addition to recognizing the legal and permitting factors associated with streamside properties, it is also important to understand that riparian environments are extremely complex natural systems with many inter-connected pieces. These pieces include unique ecosystems, intricate river dynamics that affect how a stream moves and changes over time and seasonal variations that can completely change the stream and its surrounding areas.

Riparian | ri•pair•ee•uh n | adjective

Of, relating to, or situated or dwelling on the bank of a river or other body of water., n.d.

Ecosystem | ee•koh•sis•tuhm | noun

A system, or a group of interconnected elements, formed by the interaction of a community of organisms with their environment., n.d.

Each stream includes distinct ecosystems that vary based on their elevation, their distance from the stream and the nearby land types. The organisms in these  ecosystems include insects, fish, rodents, mammals, birds and plants that range from mosses to trees. Microscopic organisms are also important pieces of these ecosystems. All of these organisms depend on each other, as well as the surrounding environment, to survive and grow.

Changes to plant communities, such as removing plants or allowing invasive weeds to take over, will affect the types of animals that live in and migrate through those areas. This is because animals depend on particular plants for food sources, as well as resting and rearing habitat. Similarly, the introduction or removal of animal species will have a direct link to the types of plants that grow and spread in the area. Many plant species are spread by animals eating and passing the seeds, or seeds that attach to the fur of an animal and then fall off in a new area.

Elements of River Dynamics

Hydraulic Engineering

How fluids move in relation to their environment


Study of water on the earth, in the earth and in the atmosphere


Study of the
characteristics and history of landforms


Study of the hysical properties of the earth


Study of various types of living matter

River dynamics, or how a river functions and moves, is a very complicated subject that combines multiple fields of study such as hydraulic engineering, hydrology, geology, geomorphology and various types of biology. Similar to the ecosystems, all of these fields are connected to each other and to the overall riparian corridor. A change in one field will have impacts on all of the others not only for that reach of the stream, but also in upstream and downstream areas. These changes will also have impacts on ‘human boundaries’ such as floodplains and floodways. For example, one landowner creating a pile of boulders and soil to direct the stream away from one of their buildings could be causing the stream to flow right into another landowner’s house. This can also impact upstream landowners by changing the way the stream is moving sediment and in turn changing the rate and location of erosion caused by the stream.

In addition to ecosystems and river dynamics, streams are also influenced by weather and seasonal changes. Streamside landowners know that the depth and flow of the water will change greatly based on the time of year and the type of weather. These changes, whether they are large floods or regular seasonal fluctuations from snowmelt and rainfall, will of course have effects on ecosystems, river mechanics and the landowner’s property.

Seasonal runoff will result in higher flows that can threaten houses and structures

All of these pieces interact and connect with each other to create what we view as the stream corridor. Part of living along a stream corridor is understanding these connections and interactions. A change in the ecosystems will not only affect the organisms, but will also impact the river dynamics. For example, the roots of many types of plants help stabilize streambanks, protecting them from erosion. If those plants are removed, the streambank is more likely to erode. This will release sediment into the stream and can result in the stream channel moving across the land. A  better understanding of these inter-connected pieces, as well as recognizing how they relate to each other, can help you be a good steward for the stream, your community and the larger watershed.