Reach Five extends from Valley Creek to approximately half way to Finley Creek. Disturbances in Reach Five include channelization, floodplain encroachment, and the conversion of riparian vegetation to other uses. Ten percent of the banks are riprapped, five percent of the length is channelized, and twenty percent is affected by constructed levees. The cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

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    1937 Photo
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    About the 1937 Aerial Photographs

    Almost complete aerial photo coverage dating from summer 1937 and taken at a scale of 1:18,000 exists of the lower mainstem (USARS 1937). The US Agricultural Research Service took these images in a low resolution black and white format. In some cases they are quite dark, which makes it difficult to determine vegetation changes. Coverage is missing for two short sections of the river: (1) just downstream of the Highway 200 Bridge at Ravalli, Montana (the upstream end of Reach Three), and (2) almost all of Reach Seven (Jocko Hollow Canyon). However, despite these limitations, and the fact that the flights were made after the floodplain had already been significantly altered by human settlement, the photos provide the best aerial picture of the historic condition.

    1937 Impacts Mapped
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    Overview of 1937 Impacts

    By 1937—which is about 70 years after European-American settlement began in the Jocko River Valley—the floodplain of the lower Jocko River had already been significantly altered by human settlement. Large areas of woody plant cover had been lost, and the railroad and high-way had been constructed. Both separated the river from the floodplain, and that had enormous impacts on the ecology of the river. As significant as these impacts were, many more were yet to come in the decades that followed 1937.

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Riparian Habitat
    In 1937, 34 percent of the floodplain of Reach 5 was covered by woody riparian vegetation, which is probably much reduced from what it was prior to 1900. Riparian com-munities are among the most productive wildife habitats and are key to healthy fish populations.

    Roads
    By 1937 some low-standard roads had been built within the floodplain for agricultural and residential purposes. The low-standard roads in Reach 5 are generally far enough away from the river to not affect the way it functions, except for where they cross it. For example, the South Valley Creek Bridge has a major impact on river function. In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    2002 Photo
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    2002 Impacts Mapped
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    scroll down

    Overview of 2002 Impacts

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Constructed Levees & Channelization
    Ten percent of the banks in Reach 5 are riprapped, 5% of the length is channelized, and 20% is affected by constructed levees. The figure at left is an example of a levee system constructed of vehicles cabled together. Although an individual feature like this may not influence overall channel stability, the cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

    Agriculture
    In 2002, 64% of the floodplain of Reach Five was agricultural land, most of that land had been riparian. Loss of riparian vegetation has reduced bank stability, riparian habitat, and stream shading. In addition, floodplain hydrology has been altered by channelizing spring channels and reducing the inter-connectivity between the channel and the floodplain.

    Homes

    By 2002 a number of houses and agricultural buildings had been constructed in the floodplain. Impacts associated with this development include channelization, floodplain encroachment, and riparian vegetative clearing, all of which has had a substantial negative impact on the river and its fish and wildlife.

    Riparian Habitat
    In 2002, 18% of the floodplain of Reach 5 was covered by woody riparian vegetation, a loss of 47% since 1937. Riparian communities are among the most productive wildlife habitats and are key to healthy fish populations.

    Roads
    In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    Channel Migration
    My Image
    Changes
    My Image
    Summary

    Summary of Changes Between 1937 and 2002

    Changes since 1937 have reduced the number of riparian acres and altered hydrologic processes:

    • The channel is less stable because of numerous channel-confinement features.
    • Pools are shallower.
    • The floodplain is inundated less often.
    • The channel is wider, straighter, and steeper.
    • In-channel sediment storage related to high bank-sediment inputs has led to channel instability, high width-to-depth ratio, and poor aquatic habitat.
    • The loss of ripairan vegetation means there is less large woody debris in the stream, less shade and food for aquatic organisms, and higher stream temperatures.
    • Floodplain hydrology has been altered by channelizing spring channels and reducing the interconnectivity between the channel and the floodplain.

Reach Five extends from Valley Creek to approximately half way to Finley Creek. Disturbances in Reach Five include channelization, floodplain encroachment, and the conversion of riparian vegetation to other uses. Ten percent of the banks are riprapped, five percent of the length is channelized, and twenty percent is affected by constructed levees. The cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

    1937 Photo
    My Image
    1937 Impacts Mapped
    My Image

    Overview of 1937 Impacts

    By 1937—which is about 70 years after European-American settlement began in the Jocko River Valley—the floodplain of the lower Jocko River had already been significantly altered by human settlement. Large areas of woody plant cover had been lost, and the railroad and high-way had been constructed. Both separated the river from the floodplain, and that had enormous impacts on the ecology of the river. As significant as these impacts were, many more were yet to come in the decades that followed 1937.

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Riparian Habitat
    In 1937, 34 percent of the floodplain of Reach 5 was covered by woody riparian vegetation, which is probably much reduced from what it was prior to 1900. Riparian com-munities are among the most productive wildife habitats and are key to healthy fish populations.

    Roads
    By 1937 some low-standard roads had been built within the floodplain for agricultural and residential purposes. The low-standard roads in Reach 5 are generally far enough away from the river to not affect the way it functions, except for where they cross it. For example, the South Valley Creek Bridge has a major impact on river function. In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    2002 Photo
    My Image
    2002 Impacts Mapped
    My Image

    Overview of 2002 Impacts

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Constructed Levees & Channelization
    Ten percent of the banks in Reach 5 are riprapped, 5% of the length is channelized, and 20% is affected by constructed levees. The figure at left is an example of a levee system constructed of vehicles cabled together. Although an individual feature like this may not influence overall channel stability, the cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

    Agriculture
    In 2002, 64% of the floodplain of Reach Five was agricultural land, most of that land had been riparian. Loss of riparian vegetation has reduced bank stability, riparian habitat, and stream shading. In addition, floodplain hydrology has been altered by channelizing spring channels and reducing the inter-connectivity between the channel and the floodplain.

    Homes

    By 2002 a number of houses and agricultural buildings had been constructed in the floodplain. Impacts associated with this development include channelization, floodplain encroachment, and riparian vegetative clearing, all of which has had a substantial negative impact on the river and its fish and wildlife.

    Riparian Habitat
    In 2002, 18% of the floodplain of Reach 5 was covered by woody riparian vegetation, a loss of 47% since 1937. Riparian communities are among the most productive wildlife habitats and are key to healthy fish populations.

    Roads
    In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    Channel Migration
    My Image
    Changes
    My Image
    Summary

    Summary of Changes Between 1937 and 2002

    Changes since 1937 have reduced the number of riparian acres and altered hydrologic processes:

    • The channel is less stable because of numerous channel-confinement features.
    • Pools are shallower.
    • The floodplain is inundated less often.
    • The channel is wider, straighter, and steeper.
    • In-channel sediment storage related to high bank-sediment inputs has led to channel instability, high width-to-depth ratio, and poor aquatic habitat.
    • The loss of ripairan vegetation means there is less large woody debris in the stream, less shade and food for aquatic organisms, and higher stream temperatures.
    • Floodplain hydrology has been altered by channelizing spring channels and reducing the interconnectivity between the channel and the floodplain.

My Image

Reach Five extends from Valley Creek to approximately half way to Finley Creek. Disturbances in Reach Five include channelization, floodplain encroachment, and the conversion of riparian vegetation to other uses. Ten percent of the banks are riprapped, five percent of the length is channelized, and twenty percent is affected by constructed levees. The cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

    1937 Photo
    My Image

    About the 1937 Aerial Photographs

    Almost complete aerial photo coverage dating from summer 1937 and taken at a scale of 1:18,000 exists of the lower mainstem (USARS 1937). The US Agricultural Research Service took these images in a low resolution black and white format. In some cases they are quite dark, which makes it difficult to determine vegetation changes. Coverage is missing for two short sections of the river: (1) just downstream of the Highway 200 Bridge at Ravalli, Montana (the upstream end of Reach Three), and (2) almost all of Reach Seven (Jocko Hollow Canyon). However, despite these limitations, and the fact that the flights were made after the floodplain had already been significantly altered by human settlement, the photos provide the best aerial picture of the historic condition.

    1937 Impacts Mapped
    My Image
    scroll down

    Overview of 1937 Impacts

    By 1937—which is about 70 years after European-American settlement began in the Jocko River Valley—the floodplain of the lower Jocko River had already been significantly altered by human settlement. Large areas of woody plant cover had been lost, and the railroad and high-way had been constructed. Both separated the river from the floodplain, and that had enormous impacts on the ecology of the river. As significant as these impacts were, many more were yet to come in the decades that followed 1937.

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Riparian Habitat
    In 1937, 34 percent of the floodplain of Reach 5 was covered by woody riparian vegetation, which is probably much reduced from what it was prior to 1900. Riparian com-munities are among the most productive wildife habitats and are key to healthy fish populations.

    Roads
    By 1937 some low-standard roads had been built within the floodplain for agricultural and residential purposes. The low-standard roads in Reach 5 are generally far enough away from the river to not affect the way it functions, except for where they cross it. For example, the South Valley Creek Bridge has a major impact on river function. In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    2002 Photo
    My Image
    2002 Impacts Mapped
    My Image
    scroll down

    Overview of 2002 Impacts

    Bridges
    The South Valley Creek Road Bridge has created several problems, including bank erosion and abutment scour. Rip-rap has been dumped along the down-stream east bank. There is bank erosion on the east bank downstream of the rip-rap. For these reasons and because of significant floodplain constriction and backwater effects, this bridge has a major impact on the river.

    Constructed Levees & Channelization
    Ten percent of the banks in Reach 5 are riprapped, 5% of the length is channelized, and 20% is affected by constructed levees. The figure at left is an example of a levee system constructed of vehicles cabled together. Although an individual feature like this may not influence overall channel stability, the cumulative effect of numerous channel confinement features can lead to reach-scale channel instability.

    Agriculture
    In 2002, 64% of the floodplain of Reach Five was agricultural land, most of that land had been riparian. Loss of riparian vegetation has reduced bank stability, riparian habitat, and stream shading. In addition, floodplain hydrology has been altered by channelizing spring channels and reducing the inter-connectivity between the channel and the floodplain.

    Homes

    By 2002 a number of houses and agricultural buildings had been constructed in the floodplain. Impacts associated with this development include channelization, floodplain encroachment, and riparian vegetative clearing, all of which has had a substantial negative impact on the river and its fish and wildlife.

    Riparian Habitat
    In 2002, 18% of the floodplain of Reach 5 was covered by woody riparian vegetation, a loss of 47% since 1937. Riparian communities are among the most productive wildlife habitats and are key to healthy fish populations.

    Roads
    In places, the highway has separated the river from wetland and riparian communities on the floodplain (although in the short piece of Reach 5 shown here, the highway is a long distance from the river and has minimal impact). Isolating these areas interrupted important river processes vital to fish and wildlife.

    Railroad
    With the exception of the downstream end of Reach 5, the railroad is far enough away from the river so that it's impact on the channel is minimal. At the downstream end (down-stream from the area shown on this map), channelization for the railroad and highway has altered channel stability.

    Channel Migration
    My Image
    Changes
    My Image
    Summary

    Summary of Changes Between 1937 and 2002

    Changes since 1937 have reduced the number of riparian acres and altered hydrologic processes:

    • The channel is less stable because of numerous channel-confinement features.
    • Pools are shallower.
    • The floodplain is inundated less often.
    • The channel is wider, straighter, and steeper.
    • In-channel sediment storage related to high bank-sediment inputs has led to channel instability, high width-to-depth ratio, and poor aquatic habitat.
    • The loss of ripairan vegetation means there is less large woody debris in the stream, less shade and food for aquatic organisms, and higher stream temperatures.
    • Floodplain hydrology has been altered by channelizing spring channels and reducing the interconnectivity between the channel and the floodplain.