Early on in Explore the River you were introduced to the "Four C's", the characteristics of a healthy trout stream: Cold water temperatures for successful trout spawning and rearing and quality adult habitat; Clean stream substrates for successful fish spawning and egg incubation; Complex habitat features for adequate fish cover and food availability; and Connected habitats to allow movement of fish among various habitats during different life-history stages. So what's happened to the Four C's on the Jocko River over the last 100 years of residential development, agriculture, logging, road and bridge construction, and other human activities? Click through the slides using the slide-navigation buttons () below.
Cold: Is the River Still Cold?
In 1891, a biologist named Barton Everman took the Jocko River's temperature and found it was ideal for bull trout, which need cold water (they cannot live in streams that have prolonged temperatures above 58° F). Compare his results with current Jocko River temperatures shown at left.
Jocko River in 1891—"We examined this stream near the railroad station at Ravalli… The water of the river is clear and cold, the temperature at 5 p.m., July 31, being 58°F…."(Barton W. Everman).
Jocko River from 1999 to 2003—"An examination of water temperatures at 5 p.m. on July 31 each year over a five-year period suggests that the river is now much warmer. The average temperature was 64.5°F and ranged between 63°F and 68°F, a rise of 5 to 10°F over the 1901 temperature, enough to make the lower river unsuitable or marginal for bull trout in the summer…The cause? riparian vegetation clearing, irrigation withdrawals, and channelization." (CSKT 2004).
1891
Click on the chart above to see the change in temperature over 112 years.
2003
Clean: Is the River Still Clean?
We don't know just how clean the Jocko River was before European-American settlement, but we can assume water quality was very high. Today it is somewhat degraded due to the loss of riparian cover, agricultural practices, irrigation, and other land uses.
Jocko River in 1891—"The water of the river is clear and cold…The Jocko is a very pretty river, and is regarded by sportsmen as a very good trout stream…" (Barton W. Everman). Historically, well-vegetated streamside areas and natural flows would have provided bank stability, resulting in relatively low fine sediment levels and very good water quality.
Jocko River today—"Data from tributaries like Finley Creek suggest that human activities are adding sediment to the river. Nutrient concentrations and turbidity values increase as one moves downstream, but the magnitude of these increases, at least with respect to nutrients and turbidity, is low relative to other streams on the Reservation. The increases are likely due to the loss of riparian vegetation, livestock grazing, irrigation return flows, housing development, and poor agricultural practices." (Adapted from the Tribes' ARCO Plan of 2000).
Sediment—soil and silt that washes into the stream—smothers trout eggs, and kills them. Many aquatic insects also need clean gravels. The image above shows the impact of sediment on trout eggs. You can use the dots to toggle between conditions: a stream with clean water and healthy trout eggs and a stream full of sediment where the trout eggs have suffocated and died.
Complex: Is the River Still Complex?
A stream with complex habitat has all of the habitat components that you would find in an undisturb-ed stream and in roughly the same proportions—pools, riffles, runs, and glides; high levels of shade and undercut banks; abundant woody debris in the stream channel; and groundwater upwellings. Healthy trout populations are strongly associated with these kinds of habitat attributes.
1891: Complex
Jocko River in 1891—Well-vegetated streamside areas pro-vided overhead cover. Pieces of large wood from riparian forests frequently dropped into the stream, creating channel complexity and quality fish habitat in the form of large, deep pools and abundant instream cover. Large wood inputs also caused channel migrations and maintained the interaction between groundwater aquifers and surface waters. Off-channel habitats such as oxbow wetlands and spring brooks were also plentiful.
Today: Much Simpler
Jocko River today—Habitat conditions vary widely in the lower Jocko. Some areas are near their potential, others are severely degraded. Livestock grazing, transportation corridors, riparian clearing, non-native plants, channelization, irrigation water withdrawals, and confinement of the stream channel have compromised habitat complexity. Removal of riparian vegetation can initiate channel changes and eliminate sources of large wood, which reduces habitat complexity by reducing the formation of large, deep pools and overhead cover.
Connected: Is the River Still Connected?
Connected in this context has two meanings: The first refers to the connection between instream habitats so fish have access to all the various habitats they need to spawn, rear, and live as adults. The second refers to the river being connected to the floodplain. Both are important. How have these connections faired over the last 100 years? Click the buttons to learn the answer.
Instream Habitats
1891: Connected
Jocko River in 1891—Prior to 1913 there were no dams on the Clark Fork River. Every year, adfluvial bull trout migrated freely between the headwaters of the Jocko River and Lake Pend d'Oreille to spawn, a 350-mile round trip. And fluvial bull trout moved without restriction between the Jocko, Clark Fork, and Flathead Rivers. There was free access to all the habitats bull trout needed for their spawning, rearing, and adult life-history needs.
Today: No Longer Connected
Jocko River today—Three dams on the lower Clark Fork River have blocked migration of fluvial and adfluvial Jocko River bull trout. Built in 1913, Thompson Falls Dam eliminated migration and spawning access from Lake Pend Oreille to 86 percent of the Clark Fork River basin, including the Jocko River. In 1952, Cabinet Gorge Dam further isolated bull trout from spawning habitat. Noxon Rapids Dam, built in the 1950s, completed the series of three impoundments.
Connection to the Floodplain
1891: Connected
Jocko River—Prior to European-American settlement, nothing separated the Jocko River from its floodplain. Besides the off-channel wetlands and other riparian habitats that the floodplain provided, it acted like a sponge, absorb-ing floodwaters and filtering fine sediments transported by the river. Floodwaters retained in the floodplain were then released back to the river as its flows receded over the course of the year. Shallow groundwater flowing into the river late in the year maintains the base flows essential for healthy aquatic communities.
Today: No Longer Connected in Many Places
Jocko River today—Disconnecting a river from its floodplain, in other words, keeping flood flows within the active channel, has predictable repercussions for channel stability and aquatic habitat. The increased energy resulting from excess water in the channel increases the erosion of the channel during floods. Perhaps even more serious, disconnecting the river from the floodplain reduces the frequency of water-table recharge. So late in the summer when it is hot and dry and flows in the river are low and warm, there is no cool groundwater flowing back into the river. Fish and wildlife suffer.
Early on in Explore the River you were introduced to the "Four C's", the characteristics of a healthy trout stream: Cold water temperatures for successful trout spawning and rearing and quality adult habitat; Clean stream substrates for successful fish spawning and egg incubation; Complex habitat features for adequate fish cover and food availability; and Connected habitats to allow movement of fish among various habitats during different life-history stages. So what's happened to the Four C's on the Jocko River over the last 100 years of residential development, agriculture, logging, road and bridge construction, and other human activities? Click through the slides using the slide-navigation buttons () below.
Cold: Is the River Still Cold?
In 1891, a biologist named Barton Everman took the Jocko River's temperature and found it was ideal for bull trout, which need cold water (they cannot live in streams that have prolonged temperatures above 58° F). Compare his results with current Jocko River temperatures shown at left.
Jocko River in 1891—"We examined this stream near the railroad station at Ravalli… The water of the river is clear and cold, the temperature at 5 p.m., July 31, being 58°F…."(Barton W. Everman).
Jocko River from 1999 to 2003—"An examination of water temperatures at 5 p.m. on July 31 each year over a five-year period suggests that the river is now much warmer. The average temperature was 64.5°F and ranged between 63°F and 68°F, a rise of 5 to 10°F over the 1901 temperature, enough to make the lower river unsuitable or marginal for bull trout in the summer…The cause? riparian vegetation clearing, irrigation withdrawals, and channelization." (CSKT 2004).
1891
Click on the chart above to see the change in temperature over 112 years.
2003
Clean: Is the River Still Clean?
We don't know just how clean the Jocko River was before European-American settlement, but we can assume water quality was very high. Today it is somewhat degraded due to the loss of riparian cover, agricultural practices, irrigation, and other land uses.
Jocko River in 1891—"The water of the river is clear and cold…The Jocko is a very pretty river, and is regarded by sportsmen as a very good trout stream…" (Barton W. Everman). Historically, well-vegetated streamside areas and natural flows would have provided bank stability, resulting in relatively low fine sediment levels and very good water quality.
Jocko River today—"Data from tributaries like Finley Creek suggest that human activities are adding sediment to the river. Nutrient concentrations and turbidity values increase as one moves downstream, but the magnitude of these increases, at least with respect to nutrients and turbidity, is low relative to other streams on the Reservation. The increases are likely due to the loss of riparian vegetation, livestock grazing, irrigation return flows, housing development, and poor agricultural practices." (Adapted from the Tribes' ARCO Plan of 2000).
Sediment—soil and silt that washes into the stream—smothers trout eggs, and kills them. Many aquatic insects also need clean gravels. The image above shows the impact of sediment on trout eggs. You can use the dots to toggle between conditions: a stream with clean water and healthy trout eggs and a stream full of sediment where the trout eggs have suffocated and died.
Complex: Is the River Still Complex?
A stream with complex habitat has all of the habitat components that you would find in an undisturb-ed stream and in roughly the same proportions—pools, riffles, runs, and glides; high levels of shade and undercut banks; abundant woody debris in the stream channel; and groundwater upwellings. Healthy trout populations are strongly associated with these kinds of habitat attributes.
1891: Complex
Jocko River in 1891—Well-vegetated streamside areas pro-vided overhead cover. Pieces of large wood from riparian forests frequently dropped into the stream, creating channel complexity and quality fish habitat in the form of large, deep pools and abundant instream cover. Large wood inputs also caused channel migrations and maintained the interaction between groundwater aquifers and surface waters. Off-channel habitats such as oxbow wetlands and spring brooks were also plentiful.
Today: Much Simpler
Jocko River today—Habitat conditions vary widely in the lower Jocko. Some areas are near their potential, others are severely degraded. Livestock grazing, transportation corridors, riparian clearing, non-native plants, channelization, irrigation water withdrawals, and confinement of the stream channel have compromised habitat complexity. Removal of riparian vegetation can initiate channel changes and eliminate sources of large wood, which reduces habitat complexity by reducing the formation of large, deep pools and overhead cover.
Connected: Is the River Still Connected?
Connected in this context has two meanings: The first refers to the connection between instream habitats so fish have access to all the various habitats they need to spawn, rear, and live as adults. The second refers to the river being connected to the floodplain. Both are important. How have these connections faired over the last 100 years? Click the buttons to learn the answer.
Instream Habitats
1891: Connected
Jocko River in 1891—Prior to 1913 there were no dams on the Clark Fork River. Every year, adfluvial bull trout migrated freely between the headwaters of the Jocko River and Lake Pend d'Oreille to spawn, a 350-mile round trip. And fluvial bull trout moved without restriction between the Jocko, Clark Fork, and Flathead Rivers. There was free access to all the habitats bull trout needed for their spawning, rearing, and adult life-history needs.
Today: No Longer Connected
Jocko River today—Three dams on the lower Clark Fork River have blocked migration of fluvial and adfluvial Jocko River bull trout. Built in 1913, Thompson Falls Dam eliminated migration and spawning access from Lake Pend Oreille to 86 percent of the Clark Fork River basin, including the Jocko River. In 1952, Cabinet Gorge Dam further isolated bull trout from spawning habitat. Noxon Rapids Dam, built in the 1950s, completed the series of three impoundments.
Connected: Is the River Still Connected?
Connected in this context has two meanings: The first refers to the connection between instream habitats so fish have access to all the various habitats they need to spawn, rear, and live as adults. The second refers to the river being connected to the floodplain. Both are important. How have these connections faired over the last 100 years? Click the buttons to learn the answer.
Connection to the Floodplain
1891: Connected
Jocko River—Prior to European-American settlement, nothing separated the Jocko River from its floodplain. Besides the off-channel wetlands and other riparian habitats that the floodplain provided, it acted like a sponge, absorb-ing floodwaters and filtering fine sediments transported by the river. Floodwaters retained in the floodplain were then released back to the river as its flows receded over the course of the year. Shallow groundwater flowing into the river late in the year maintains the base flows essential for healthy aquatic communities.
Today: No Longer Connected in Many Places
Jocko River today—Disconnecting a river from its floodplain, in other words, keeping flood flows within the active channel, has predictable repercussions for channel stability and aquatic habitat. The increased energy resulting from excess water in the channel increases the erosion of the channel during floods. Perhaps even more serious, disconnecting the river from the floodplain reduces the frequency of water-table recharge. So late in the summer when it is hot and dry and flows in the river are low and warm, there is no cool groundwater flowing back into the river. Fish and wildlife suffer.