Endangered and Threatened Fishes in the Klamath River Basin Causes of Decline and Strategies for Recovery (2004) / Chapter Skim
Currently Skimming:
4. Current and Historical Status of River and Stream Ecosystem
4. Current and Historical Status of River and Stream Ecosystem
Pages 144-178
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 144... ...
This chapter considers the major streams ancT rivers of the Klamath basin ancT analyzes anthropogenic changes in conditions that affect especially the coho salmon ancT enciangerecT suckers but also other fishes ancT aquatic life generally. Each section of this chapter considers either a specific section of the main-stem Klamath River or of its tributaries; locations are clesignatecT in river mi (RM)
|
From page 145... ...
The cause of the change is uncertain, but it is inclepenclent of climatic variability ancT probably is relatecT to a combination of river channelization, reduction in area of wetiancTs, timber harvest, ancT other factors that recluce evapotranspiration in the watershed (Risley ancT Laenen 19991. Increased flows from the Williamson ancT Sprague drainages, couplecT with current lancT-use practices, probably have increased phosphorus transport within the basin through greater erosion that leacTs to higher transport of suspenclecT sediments, which carry phosphorus.
|
From page 146... ...
In aciclition, shacling couicI recluce the accumulation of algae ancI rooted aquatic plants on the sicles ancI becis of tributaries. Plants produce oxygen through photosynthesis ancI thereby potentially increased concentrations of clissolvecI oxygen cluring the clay, but nocturnal respiration ancI the clegraciation of accumulations of nonliving organic matter that they produce can cause oxygen clepletion.
|
From page 147... ...
The effect of management on the annual cycle of water flow has been the subject of consiclerable research on historical flows in the main stem. Before the creation of the I(lamath Project ancI other modifications of flow, the I(lamath River hacI a relatively smooth annual hycirograph with high flows in winter ancI spring that cleclinecI graclually cluring summer ancI recovered in fall.
|
From page 148... ...
in its review of the hycTrology of the I(lamath River, the changes in flow below Iron Gate Dam are attributable to watermanagement practices in the upper ancT lower I(lamath basin. The shift toward an earlier peak in annual runoff appears to be associated with increased flows in the I(lamath River from the Lost River cTiversions ancT the loss of seasonal hycTrologic buffering that originally was associated with overflow into Lower I(lamath Lake ancT Tule Lake.
|
From page 149... ...
_~ . ~6/1/1997 8/1/1997 10/1/1997 FIGURE 4-3 Simulated and measured temperature in the I(lamath River below Iron Gate Dam.
|
From page 150... ...
...... ,,_ 8 190 180 170 160 150 140 River Mile FIGURE 4-4 Simulated daily maximum, mean, and minimum water temperatures on the Klamath River from Iron Gate Dam to Seiad Valley for Iron Gate Dam releases of 1,000 cfs (A)
|
From page 151... ...
The increased volume of water ancI shorter transit time, however, recluce the effect of nocturnal cooling in the reach between Iron Gate Dam ancI SeiacI, ancI raise minimum temperatures for about two-thircis of the reach. Although increased flows recluce mean ancI maximum temperatures, the increase in minimum temperatures may aciversely affect fish that are at their limits of thermal tolerance (Chapters 7 ancI 81.
|
From page 152... ...
Even when nutrient concentrations are high, however, blooms of phytoplankton, such as those in Upper I(lamath Lake, clo not occur in streams or rivers of moderate to high velocity because flow limits the accumulation of suspenclecI algae. Conditions may be favorable in the main stem for the growth of phytoplankton cluring low flow, when the water is moving slowly, ancI growth of attached algae ancI aquatic vascular plants also can be stimulatecI by nutrients.
|
From page 153... ...
Use of remaining habitat is contingent on flow anti water quality, both of which may be inadequate in ciry years. Mean annual runoff from the Shasta River is 136,000 acre-ft, which is less than 1% of the runoff of the I(lamath River at Orieans.
|
From page 154... ...
Seven major diversion clams ancI numerous smaller clams or weirs are on the Shasta River ancI its tributaries below Dwinnell Dam (Figure 4-71. When the diversions are in operation, they substantially ancI rapicIly recluce flows in the main stem (Figure 4-61.
|
From page 155... ...
CURRENT AND HISTORICAL STATUS OF RIVER AND STREAM ECOSYSTEMS 155 Hombrook~ ~ ~ ~~; J ~ it.' of' DIG' ~4~..3> Grenades ~ k ¢ FIGURE 4-7 Map depicting substantial water diversions from the Shasta River below Dwinnell Dam. Note that the Shasta River flows north and drains into the Klamath River.
|
From page 156... ...
For example, the Big Springs Irrigation District ceased using surface diversions ancI switched to grounc~water wells in the 1980s to meet its water needs; these highly procluctive wells may have contributed to the reported clewatering of the springs that historically fecI Big Springs Creek. Recent surveys have shown that channel conditions in the main stem of the Shasta River ancI its most important tributary, Parks Creek, generally are poor ancI may limit salmonicI production.
|
From page 157... ...
The low flows also recluce habitat for salmonicis anti increase the adverse effects of diversion structures on migration. Substantial reduction of flows by water withcirawal anti the associated poor water quality probably are principal causes of clecline in salmonicI production in the Shasta watershed.
|
From page 158... ...
The causes of high temperatures inclucle chronic low flow clue to agricultural diversions, lack of riparian shacling, anti aciclition of warm irrigation tailwater. Temperature simulations for the Shasta River concluctecI by Abbott (2002)
|
From page 159... ...
Small increases in flow couicI recluce transit time substantially ancI thus increase the area of the river that maintains tolerable temperatures. Increases in riparian vegetation also couicI help to sustain lower water temperatures.
|
From page 160... ...
Along the main stem of the Scott River, surface flow ceases in several reaches cluring August anti September of average anti ciry years. Discontinuous flow occurs into the fall.
|
From page 161... ...
Unlike the Shasta River, the Scott River shows lack of significant recovery of base flow cluring late fall ancI winter in years of low rainfall, indicating lack of resiliency in the grounc~water reservoirs. Because low base flow cluring summer ancI early fall is a natural element of the Scott River hyciropattern, ciry conditions in some reaches of the river may have occurred at some times before water management.
|
From page 162... ...
conclitions, anc! those associated with the main stem of the Scott River.
|
From page 163... ...
rated the hoiclover of aclults before spawning as fair, spawning habitat as fair, anti juvenile rearing habitat as poor. The clecline in salmonicI habitat conditions on the main stem of the Scott is caused by channel alterations, low flow, anti poor water quality.
|
From page 164... ...
164 FISHES IN THE KLAMATH RIVER BASIN are naturally self-limiting, to grounc~water wells, has exacerbated the apparent overappropriation of water in the watershed. That problem is compounclecI by a limitecI watermaster service in the basin anti insufficient records, so it is not known whether diverters are adhering to their appropriative rights.
|
From page 165... ...
. The clecline in late summer ancI fall runoff is a consiclerable challenge to restoration of salmonicI hoicling, spawning, anti rearing conditions in the Scott River.
|
From page 166... ...
B 7 60 50 40 30 20 10 FISHES IN THE KLAMATH RIVER BASIN Crop Patterns Scott River Valley 1958 1968 1978 1991 Groundwater Wells Scott River Domestic Wells T —— Irrigation Wells | -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- o- = 1 V
|
From page 167... ...
I... River Mile from Confluence FIGURE 4-13 Plot of downstream changes in maximum weekly average water temperature on the main stem of the Scott River during summer.
|
From page 168... ...
Historical ancI continuing placer mining has reclucecI riparian cover ancI clisturbecI spawning ancI hoicling sites in the basin as well. Increased water temperatures have been noted in the Salmon River cluring late-summer low-flow periods, but their cause is unclear; they may be natural or may be in part a byproduct of logging ancI fires.
|
From page 169... ...
Hycirologically, the Trinity watershed is broacIly similar to the Scott ancI Salmon watersheds. Prior to construction of the Trinity River Diversion (TRD)
|
From page 170... ...
{\ , , ( 1 40°30 Anderson I~I < o lo .~ 20 ~~s 1 1 1 1 1 1 0 70 20 ~~ec~ FICURF 4-13 index map of the Trinity River ~atcrshcd. Source: Bodied Tom USP(S/HVT 1999.
|
From page 171... ...
As with most tributary watersheds of the I(lamath system, logging, mining, and grazing have reduced the quantity and quality of salmon habitat in the Trinity watershed. The greatest effects have occurred in the South Fork of the Trinity and on the main stem below Lewiston Dam and above the confluence of the main stem with the North Fork.
|
From page 172... ...
The magnitude of the cliversions ancI associated flow release scheclules eliminatecI winter ancI spring floocI pulses in the main stem of the Trinity (Figure 4-16)
|
From page 173... ...
The hycirographs consistent with these recommendations still allow for clelivery of water to the CVP, but shape the hycirographs so that they support the life-history neecis of salmonicis, inclucling reintroducing disturbance to control establishment ancI growth of riparian vegetation, coarse sediment transport to establish pools anti riffles ancI to clean spawning gravels, ancI sufficient flows to recluce water temperatures for rearing. The TRFE also contained an adaptive management approach that calls for assessment of the effect of changes in flow regime ancI adjustments as necessary to improve the success of the program.
|
From page 174... ...
Given the size of the Trinity River watershed ancI its large amount of runoff, the operations of the TRD must affect the quality of habitat in the lowermost I(lamath River ancI its estuary. There is little publishecI information, however, on the effects of the Trinity on the lowermost I(lamath ancI the estuary.
|
From page 175... ...
MINOR TRIBUTARIES TO THE LOWER KLAMATH MAIN STEM (RM 192-0) Many small tributaries enter the main-stem Klamath between Iron Gate Dam ancI the mouth of the river.
|
From page 176... ...
Flows in the lowermost I(lamath are driven by a seasonally varying mixture of main-stem flow ancI accretions of water from tributaries. For example, water reaching the river via the Iron Gate Dam contributes less than 20% of the flow at Orieans in May ancI lune (1962-19911.
|
From page 177... ...
Even though hycirologic change in the lowermost I(lamath main stem seems too small to have causecI large changes in the estuary, significant impairment of the estuary couicI have occurred through warming of the river water ancI through increased organic loacling causecI by eutrophication ancI alteration of flow regimes in heac~waters. The estuary couicI show adverse chemical conditions as a result of these changes, ancI coho in the estuary thus couicI be affected.
|
From page 178... ...
Still, additional research that would clarify the interactions between hydrology and temperature, especially as affected by water-management strategies, is needed. Considerable research on this topic is in progress, but field investigations have focused primarily on the river between Iron Gate Dam and Orieans.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.