Make checks payable to DEPARTMENT OF WATER RESOURCES.
California residents add sales tax.

FIGURES

(Figures are not available for this on-line publication. Please refer to the printed document for figures.)

Total Monthly Precipitation (Shasta and Klamath Rivers Study Area)

Mean Monthly Flows(Klamath River near Seiad Valley.

Upper Klamath River Streambed Profile.

Electrical Conductivity in Klamath River near Seiad Valley (F3-1430.00).

Electrical Conductivity in Shasta near Yreka (F2-1050.00).

Dissolved Oxygen and Temperature - Klamath River near Seiad Valley (F3-1430.0).

Diurnal Variations of Temperature and Dissolved Oxygen:

Klamath River below Iron Gate.

Klamath River at Randolph Collier Rest Stop.

Klamath River below Shasta River.

Klamath River above Hamburg Reservoir Site.

Klamath Rive at Sarah Totten Campground.

Shasta River near Yreka..

Yreka Creek above Shasta River.

Shasta River above Yreka Creek..

Shasta River below Little Shasta River.

Shasta River above Little Shasta River.

Shasta River near Grenada.

Shasta River near Big Springs.

Shasta River below Dwinell Reservoir.

Scott River at Mouth.

The Klamath River, originating in the south central portion of Oregon, flows southwesterly through five Northern California counties and terminates in the Pacific Ocean some 20 miles south of Crescent City. The river produces over 16 percent of the combined flow of all water-producing areas in California. This vast source of water is now protected from further development under the California Wild and Scenic Rivers Act of 1970.

The river and its tributaries are a vital source of water to Northern California. One of the most important uses of these waters down stream of Iron Gate Dam, although nonconsumptive, is the excellent habitat they provide for anadromous salmon and steelhead fisheries. The Shasta River system, tributary to the Klamath River, is used extensively and constitutes about 90 percent of the irrigation water supply in Shasta Valley. It is also used as a migration route for salmon and steelhead and provides spawning habitat for these fish.

The quality of these two rivers has been monitored at several stations for more than 20 years and resulting data show a great variation. Complaints have been received about excessive foaming, water discoloration, overabundance of algae, and unsightliness. This study was undertaken to investigate the water quality and its variation, from Iron Gate Dam to the gauging station, "Klamath River near Seiad Valley".

The information developed in this study is essential not only in managing this water resource to maximize its beneficial uses, but also to plan for future conjunctive ground and surface water uses. It should also be useful to help develop more definitive objectives for water quality control plans.

This report includes a brief overview of the study area, its geology, climate, development, and water supply. It describes the hydrologic conditions that prevail in the study area, summarizes water quality data, and sets forth findings and conclusions.

Wayne S. Gentry, Chief

Northern District

Significant findings of this investigation are:

1. The average annual flow in the Klamath River below Iron Gate Dam is about 1,600,000 acre-feet, while downstream at Seiad Valley it is 3,000,000 acre-feet.

2- Approximately 50 percent of the average annual flow in the river at Seiad Valley originates from sources upstream of the study area.

3. Although the runoff in the Klamath River was only 50 percent of normal during 1981, the average runoff during the 3-year study period (1981-1983) was about 125 percent of normal.

4. The Shasta River with 11 percent of the Klamath River drainage area above Seiad Valley contributes only about 5 percent of the flow in the Klamath River at that point.

5. Surface water resources in the Klamath River downstream of Iron Gate Dam have limited use; however, surface waters of the Shasta River are extensively developed and used.

6. Distribution and use of several tributary waters to the Klamath River are currently under the jurisdiction of court decrees.

7. Electrical conductivity values rarely exceed 300 micromhos/cm in the Klamath River and 700 micromhos/cm in the Shasta River.

8. The waters of the Klamath and its tributaries are strongly bicarbonate in character and generally contain low concentrations of chlorides and sulfates.

9. Average boron concentrations ranges from 0.1 mg/L in the Klamath, to 0.5 mg/L in the Shasta River.

10. The pH of Klamath River waters usually ranges from 7.0 to 9.0, with the highest values occurring in the summer during periods of high biological productivity.

11. Nutrient concentrations found in the Klamath and Shasta Rivers are generally higher than those found in most other Northern California waters.

12. Dissolved oxygen levels in the Klamath River seldom drop below 8 mg/L; however, the summer levels have often dropped to near 6 mg/L and in the Shasta River below 5 mg/L.

13. Diel DO fluctuations of 3 mg/L in the Klamath and 5 mg/L in the Shasta River, common during the summer months, are indicative of a productive river system.

14. Seasonal and diel temperature changes are prominent in the Klamath River. Temperatures range from winter lows near l' C to summer highs near 27' C, while diel variations frequently exceed 5' C during the summer.

15. During the summer months, the Klamath River usually looks turbid; however, this condition is the result of organic coloring rather than suspended matter.

16. The nutrient balance, although of limited accuracy, does indicate that large amounts of nitrogen and phosphorus, primarily from upstream sources, pass through the river system each year.

17. Benthic macroinvertebrate populations are characteristic of rivers with moderate to high levels of biologic productivity.

18. The frequent occurrence and abundance of scraper and collector organisms indicate high levels of primary productivity.

19. Periphyton growths have created nuisance conditions in reaches of both the Klamath and Shasta Rivers.

This investigation has resulted in the following conclusions.

1. As the waters of the Klamath River are extensively developed upstream of Iron Gate Dam, and with limited additional development expected in the study reach, future flow patterns will probably change little and will continue to vary with the annual precipitation and water supply. Increased ground water development, however, can be expected to reduce the flows in the Shasta River.

2. The magnitude of the water quality parameters found in the Klamath River are greatly influenced by sources upstream of the study area.

3. Although there is large seasonal variation in the quality of Klamath River waters, their mineral quality is usually good to excellent.

4. Nutrient levels in the Klamath River are sufficient to support high to excessive productivity. When impounded in reservoirs, such as Iron Gate Reservoir, algal blooms will develop and nuisance conditions can be expected.

5. As the inflow of nutrients to the Shasta and Klamath Rivers is expected to remain high, periphyton will continue to be present at nuisance levels during some seasons at various locations in these systems.

6. While dissolved oxygen concentrations in the Klamath River are usually near saturation, they have at times been depressed well below saturation at some stations in the Shasta River during the summer months, producing stress that has probably contributed to fish kills and damaged ecosystems. 7. Seasonal and diel temperature changes are large and are an additional stress on aquatic organisms.

8. Any water resource management plan involving the Klamath River system should recognize the natural variability of quality and set realistic objectives that will protect this valuable water resource. Consideration should be given to the large seasonal and diel changes that occur in flow, temperature, and dissolved oxygen.

This study was undertaken to expand our knowledge of the quality of the Shasta River and the Klamath River in the reach between Iron Gate Dam and Hamburg so that these valuable water resources can be properly managed and protected. The water quality of the Shasta River has been monitored near its mouth for 26 years, as has the Klamath River at Hamburg Reservoir site and near Seiad Valley. The Klamath River below Iron Gate Reservoir has been monitored for 23 years. The resultant data have provided a valuable basis for planning this study and relating study period results to long-term conditions.

Although the monitoring records indicate that the Shasta and Klamath River waters are good to excellent in mineral quality, problems related to water temperature, high levels of biological productivity, and aesthetics are apparent.

This investigation began with a review of historic water quality data and previous reports on the Klamath and Shasta Rivers. The review indicated that water quality problems related to high nutrient content and associated excessive biologic activity were prominent in the Klamath River downstream from Iron Gate Reservoir and in portions of the Shasta River.

The field investigation started in the slimmer of 1981 and continued through the spring of 1983. Five water quality sampling surveys were conducted during the study. Samples were collected and water quality parameters measured during day and night periods to record diel quality variations during these surveys. The monitoring of water quality was also continued during this investigation at the stations with long-term records.

To provide data that would show nutrient distribution throughout the system and indicate major source areas, concentrations of nitrogen and phosphorus were measured seasonally at a network of sampling stations. In addition to these macronutrients, measurements of the more common chemical and physical parameters were made frequently and selected samples were analyzed for trace metals. Benthic invertebrate samples were also collected at selected stations.

This report includes summaries of both historic and new data developed during this investigation. Evaluations of the hydrologic conditions and water quality characteristics of the study area rivers are presented. Estimates of nitrogen and phosphorus movement through these rivers are presented. The report contains findings and conclusions as well as descriptions of the investigation and methods used.

The reach of the Klamath River in this study extends from below Iron Gate Dam near Hornbrook downstream to Hamburg (Plate 1). The river flows westerly some 50 miles through Siskiyou County and is paralleled by State Highway 96. Two major stream systems tributary to the Klamath River in this reach are the Shasta and Scott Rivers. The headwaters of the Shasta River are on the northwestern slopes of Mt. Shasta and adjacent mountain ranges near Weed, and from there the river flows northerly to its confluence with the Klamath River, about ten miles north of Yreka. The Scott River originates along the eastern slopes of the Salmon Mountains and flows northerly to its confluence with the Klamath River near Hamburg.

The area of investigation lies within two geomorphic provinces. The Cascade Range borders Shasta Valley on the east, while the Klamath Mountains border it on the west. The Klamath Mountains province includes the entire study area west of the Cascade Range. The Cascade Range is characterized by rugged topography and chains of volcanic cones with bedrocks ranging in age from pre-upper Cretaceous to Recent, and consist of thick layers of sandstone, graywacke, shales, and basalt. These formations in the eastern side of Shasta Valley are overlain by alluvium composed of sand, gravel, and clays that were deposited by streams. Most of these formations and the alluvium deposits are water-bearing. The Klamath Mountains were developed by stream erosion of an uplifted plateau and are transected by the Klamath River. The bedrocks range in age from pre-Silurian to Recent and include schist, greenstone, consolidated sedimentary rocks, and intrusive rocks ranging from granodiorite to serpentine. These formations in Scott Valley are overlain by unconsolidated alluvium consisting of sand, gravel, and clay deposits that generally produce adequate groundwater supplies.

The geographical extent of the Klamath River Basin results in a wide variety of climatic conditions. As moisture-laden air from the Pacific Ocean moves inland, it crosses the coastal mountain ranges of Northern California and Southern Oregon; as it ascends the western faces of the mountains, much of its moisture condenses and falls as rain or snow., leaving less moisture for the Cascade Range to the east. The mean annual precipitation in the basin is about 32 inches, but varies from over 60 inches annually in the northwest to 10 inches annually in Shasta Valley to the east.

The climate in this region is characterized by dry summers with high daytime temperatures and wet winters with moderate to low temperatures. About 75 percent of the annual precipitation falls between October and March and generally produces an adequate snowpack in the higher mountain ranges. In the Yreka-Montague area, the annual mean temperature is about 52 degrees F. January is the coldest month with a mean temperature of 35 degrees F. July is the warmest mouth with a mean of about 73 degrees F. Extreme temperatures in the area vary from 112 degrees to -11 degrees F.

Settlement in the Klamath River Basin began in the early 1850s with the discovery of gold in California. As populations grew, and the readily available gold supply dwindled, settlers realized the vast timber stands, the rich agricultural lands, and the recreation potential were of far greater value. The current economy has grown dependent upon these resources.

Early mining activities required the first extensive use of water, and this resource became increasingly important with the discovery of the fertile valley areas along the Scott and Shasta Rivers, which were adaptable for growing irrigated crops. The first crops of vegetables and fruit were used for local consumption, but as transportation facilities improved, outside markets for hay, beef, and dairy products created an economic change in the agricultural industry. A cattle industry began to flourish and has maintained its importance in the region, with the major crops consisting of alfalfa, grain, and meadow pasture.

Production of forest products is of major importance to the economy of the area and played an important role in its development. Most of the population centers throughout the basin developed in conjunction with saw mills. Timber harvested is predominantly pine, fir, and cedar, which are processed locally, and includes the manufacture of plywood and hardboard. Also, mining of non-metal minerals., such as sand and gravel, has contributed to the economy.

Recreational activities have increased throughout the region and influenced development and need for services. Abundant wildlife attracts visitors for hunting and fishing, while opportunities for hiking, horseback riding, or enjoying the scenic beauty bring others.

About 23,000 people live within the study area, most of them in small towns and communities scattered throughout the watershed. The largest community is the City of Yreka, which is the Siskiyou County seat. With a population of about 6,000, Yreka is located in the northwestern section of Shasta Valley and is the area's trade center supported by agricultural and wood product-associated activities. Transportation and governmental activities also contribute to the local economy.

Three major highways and a Southern Pacific Railroad line provide access to the Klamath River watershed. Interstate 5 serves as the main north-south traffic corridor; U. S. 97 provides access from the northeast and State Route 96 from the west. The railroad bisects Shasta Valley and operates a spur serving Yreka. The roads not only provide avenues for movement of products to outside markets, but also bring tourists and recreationists to the region.

The mean annual flow of the Klamath River near Iron Gate is about 1,585,000 acre-feet, while downstream near Seiad Valley it is about 2,951,000 acre-feet. The large increase is attributed to the two major tributary drainages of the Shasta and Scott Rivers and several minor drainage basins.

Most of the streamflow occurs from December through April, while water demands are greatest from May through September. In the populated valleys, with their semi-arid climate, shortages of water in mid-summer caused problems for early settlers, and numerous reservoirs were built to provide water in the summer and fall.

Even with reservoir storage, competition for the limited surface waters resulted in battles over water rights, which eventually led to water rights defined by court decrees for several tributaries to the Klamath River. In three areas within this drainage, the Department of Water Resources is now responsible for the distribution of water according to court decrees.

Ground water is increasingly used in these basins to supplement limited and extensively used surface water supplies. Since further development of the existing surface water supplies is restricted, future requirements will likely be met by additional ground water use.

Throughout the Klamath River drainage, major point-source waste discharges have been limited primarily to lumber mill operations and domestic wastes from several cities and smaller communities in the Shasta and Scott Valleys. Such wastes are typically high in organics, exert oxygen demands in the receiving waters, and are sources of phosphorus, nitrogen, and other nutrients. They also contain chlorides, sulfates, and dissolved solids, which can add to the levels found in the receiving waters.

Additional domestic wastes are discharged through cesspools or septic tanks and leach fields in several unsewered communities scattered throughout the watershed. As populations have remained low, domestic wastes probably have had little impact on the quality of the Klamath River.

The California Water Quality Control Board, North Coast Region, has adopted waste discharge requirements for the waste disposal from the larger domestic and lumber mill sources, and impacts from these sources have been minimal.

Non-point sources associated with agricultural and timber harvest activities have probably had a greater impact on the Klamath River than point sources. These activities often increase the suspended sediment loads in nearby surface waters, and materials washed into the streams can increase nutrient levels and discolor the receiving waters.

The hydrology of the Upper Klamath and Shasta River Basin is affected mainly by the areal and seasonal distribution of precipitation and the influence of snowmelt runoff. Variations in topography, vegetative cover, and geologic structure further affect the pattern of runoff, as well as the use of surface and ground waters.

The Upper Klamath and Shasta River watershed within the study area has a mean annual precipitation of about 32 inches. Approximately 85 percent of the average annual precipitation occurs between October and April, with the remainder occurring as occasional summer storms.

Precipitation patterns were abnormal during the study period (see Figure 1). During the 1981 water year, precipitation was only about 70 percent of normal. The 1982 water year had a total precipitation of 180 percent of normal with extremely heavy rainfall during November and December. The 1983 water year was 135 percent of normal with exceptionally heavy precipitation during December.

Runoff in that reach of the Klamath River within the study area between Iron Gate Reservoir and Hamburg is influenced by two major stream systems, the Shasta and Scott Rivers, and several minor tributaries. A summary of the hydrologic conditions found to exist within this system is shown in table 1. The average annual runoff values are based on the period of record for each station which vary from 22 years at Klamath River below Iron Gate Dam(1960) to 44 years at Klamath River near Seiad Valley (1912).

Table 1. Hydrologic Characteristics in the Study Area

Station	Ave. Annual Runoff 1,000 AF	Drainage Area Square Miles	Runoff %	Drainage Area %	Ratio Ave. Runoff / Drainage Area
Klamath R. bl. Iron Gate	1,585	4,630	53	67	342
Shasta R. nr. Yreka	136	793	5	11	170
Scott R. at Mouth	615	808	21	12	761
Other tributaries	615	709	21	10	867
Klamath R. nr. Seiad Valley	2,951	6,940	100	100	425

Significant variances in the runoff characteristics of the stream systems are caused by several contributing factors. Flow in the Klamath River is regulated by several upstream reservoirs, power plants, and large irrigation systems. The Shasta River, with 11 percent of the total Klamath River drainage area above Seiad Valley, contributes only 5 percent to the Klamath River flow. Shasta River flows, partly regulated by Dwinnell Reservoir (also known as Lake Shastina), supply numerous irrigation diversions, and are greatly affected by the limited rainfall in the Shasta Valley drainage basin. The high runoff in the Scott River is attributed to the absence of major storage projects in Scott Valley, steeper terrain, and the relatively high winter precipitation in most of the drainage basin.

The flow characteristics of the Klamath River near Seiad Valley are shown on Figure 2 and reflect the influence of snowmelt and surface water storage. Although less than 25 percent of the average annual precipitation falls from March through June, over 40 percent of the average annual runoff occurs during this period. Flows during 1981 were extremely low (48 percent of normal) when the precipitation during the same period was 71 percent of normal. Runoff was about 150 percent in 1982 and 165 percent in 1983, during which time the precipitation was also significantly higher than normal. The same runoff pattern occurred during these years on the upper reaches of the Klamath River as well as the Shasta and Scott Rivers.

The Klamath River streambed has a steep gradient above Copco but, as shown in Figure 3, from Copco (F3-1630.00) to Seiad Valley (F3-1430.00) its gradient is greatly reduced. Although the average gradient in this reach of the river is considered moderate at about three feet per thousand feet, the streambed does vary, having steeper to flatter sections. In the steeper reaches of the river, water velocities are typically high, while flows in the flatter reaches are characterized by lower velocities. This is reflected in the stream bottom materials, which are typically sand, gravel, cobbles, and boulders in the steeper reaches and gravels, sand, and silts in the flatter reaches.

In the Klamath River drainage upstream of Iron Gate Dam, Klamath River waters are stored and used extensively for power generation and to meet municipal, industrial, and agricultural demands, while downstream, uses are limited to small irrigation diversions by individuals and small communities located in the rugged mountainous region along the Klamath River. The two major tributaries, Shasta and Scott Rivers, accommodate the majority of the water use in the Klamath River Basin within California.

Most of the available water supply in the Shasta River Basin is used for irrigation and stock watering. approximately 50,000 irrigated acres are devoted to the major crops of meadow pasture, alfalfa, and grain. When irrigation demands are high in the summer., flows in the river are minimal soground waters are used as a supplemental supply. Dwinnell Reservoir, the largest diversion facility, stores water for downstream irrigation releases as well as the municipal water supply for the community of Montague.

The Scott River and its tributaries are also used extensively for stock watering and irrigation. Some 30,000 acres of permanent pasture and alfalfa are currently under irrigation in Scott Valley. Ground water is utilized during the irrigation season to supplement the surface water supplies.