Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute One: Every Level of Stream Flow has an Important Function
At least four types of flows are necessary to support the proper functioning of a stream system:
- Baseflow is generally the lowest flow and usually occurs during the summer months. It maintains some water in critical habitat units, keeping riffles wet and pools inundated.
- The bankfull flow is the maximum flow within a channel before water spills on to the floodplain. It provides the stream power to transport sediment and maintain high quality spawning gravels.
- Riparian flow refers to high flows that access parts of the active floodplain every few years. Riparian flow affects overhanging bank cover and the availability of large wood in the stream, which makes for complex, quality habitat.
- Floodplain flows are major flooding events that occur every 25 to 100 years. Although infrequent, they determine the architecture of the floodplain and the connection between the floodplain and active channel.
Each of these flows affect conditions in the channel, the channel's shape, streambank vegetation, and the character of the floodplain, respectively. All four also affect fish habitat in important ways. Bottom line: all four flows are absolutely key to sustaining a healthy stream.
Baseflow
Baseflow is generally the lowest flow and usually occurs during the summer months. Click the navigation dots below to see the different flows.
Bankfull Flow
Bankfull flows occur when waters rise to the highest point in the stream channel.
Riparian Flow
Riparian flows occurs when the stream overflows its banks and moves onto the floodplain.
Floodplain Flow
Floodplain flows are major flooding events that occur every 25 to 100 years.
Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute One: Every Level of Stream Flow has an Important Function
At least four types of flows are necessary to support the proper functioning of a stream system:
- Baseflow is generally the lowest flow and usually occurs during the summer months. It maintains some water in critical habitat units, keeping riffles wet and pools inundated.
- The bankfull flow is the maximum flow within a channel before water spills on to the floodplain. It provides the stream power to transport sediment and maintain high quality spawning gravels.
- Riparian flow refers to high flows that access parts of the active floodplain every few years. Riparian flow affects overhanging bank cover and the availability of large wood in the stream, which makes for complex, quality habitat.
- Floodplain flows are major flooding events that occur every 25 to 100 years. Although infrequent, they determine the architecture of the floodplain and the connection between the floodplain and active channel.
Each of these flows affect conditions in the channel, the channel's shape, streambank vegetation, and the character of the floodplain, respectively. All four also affect fish habitat in important ways. Bottom line: all four flows are absolutely key to sustaining a healthy stream.
Baseflow
Baseflow is generally the lowest flow and usually occurs during the summer months. Click the navigation dots below to see the different flows.
Bankfull Flow
Bankfull flows occur when waters rise to the highest point in the stream channel.
Riparian Flow
Riparian flows occurs when the stream overflows its banks and moves onto the floodplain.
Floodplain Flow
Floodplain flows are major flooding events that occur every 25 to 100 years.
Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute One: Every Level of Stream Flow has an Important Function
At least four types of flows are necessary to support the proper functioning of a stream system:
Baseflow
Baseflow is generally the lowest flow and usually occurs during the summer months. Click the navigation dots below to see the different flows.
Bankfull Flow
Bankfull flows occur when waters rise to the highest point in the stream channel.
Riparian Flow
Riparian flows occurs when the stream overflows its banks and moves onto the floodplain.
Floodplain Flow
Floodplain flows are major flooding events that occur every 25 to 100 years.
- Baseflow is generally the lowest flow and usually occurs during the summer months. It maintains some water in critical habitat units, keeping riffles wet and pools inundated.
- The bankfull flow is the maximum flow within a channel before water spills on to the floodplain. It provides the stream power to transport sediment and maintain high quality spawning gravels.
- Riparian flow refers to high flows that access parts of the active floodplain every few years. Riparian flow affects overhanging bank cover and the availability of large wood in the stream, which makes for complex, quality habitat.
- Floodplain flows are major flooding events that occur every 25 to 100 years. Although infrequent, they determine the architecture of the floodplain and the connection between the floodplain and active channel.
Each of these flows affect conditions in the channel, the channel's shape, streambank vegetation, and the character of the floodplain, respectively. All four also affect fish habitat in important ways. Bottom line: all four flows are absolutely key to sustaining a healthy stream.