Nutrient Loading of Surface Waters in the Upper Klamath Basin: Agricultural and Natural Sources
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D s ESS- : 1o • / 0 .a 3 Unbound issue o p • Does not circulate Special Report 1023 March 2001 Nutrient Loading of Surface Waters in the Upper Klamath Basin: Agricultural and Natural Sources 9 1011/e 40 4 6).". '7', _. r.-1 APR 2001 LIBRARY ';'.' OREGON STATE izrz, UNIVERSITY --- trl 2C2J2 OREGON STATE UNIVERSITY AGRICULTURAL EXPERIMENT STATION For additional copies of this publication, write Kenneth A. Rykbost, Superintendent Klamath Experiment Station 6941 Washburn Way Klamath Falls, OR 97603 Agricultural Experiment Station Oregon State University Special Report 1023 March 2001 Nutrient Loading of Surface Waters in the Upper Klamath Basin: Agricultural and Natural Sources Kenneth A. Rykbost Superintendent/Professor and Brian A. Charlton Faculty Research Assistant Klamath Experiment Station Klamath Falls, Oregon Partial financial support of this study from the Klamath Basin Agricultural Enhancement Endowment is gratefully recognized. NUTRIENT LOADING OF SURFACE WATERS IN THE UPPER KLAMATH BASIN: AGRICULTURAL AND NATURAL SOURCES K.A. Rykbost and B.A. Charltonl bstract development of a TMDL for Klamath Implementation of the Federal Lake and its tributaries. Insufficient data Clean Water Act and Oregon are available to determine the relative Senate Bill 1010 is proceeding under contributions of agricultural activities, two simultaneous processes in Oregon. natural background sources, and other The Oregon Department of potential sources of nutrient enrichment Environmental Quality is responsible for to establish numerical limits for nutrient developing Total Maximum Daily Load loading from agricultural lands. (TMDL) allocations for water-quality From 1998 through 2000, the limited water bodies. The Oregon Klamath Experiment Station has Department of Agriculture is striving to investigated nutrient loading from develop Management Area Plans to drainage of agricultural lands adjacent to provide guidance for management of Klamath Lake, natural background private agricultural lands to meet Clean sources including major springs and Water Act objectives. Both processes several artesian wells, and loading to the seek input from local advisory Klamath Irrigation Project from committees comprised of landowners diversions out of Klamath Lake and and other stakeholders, and technical Klamath River. Findings indicate review committees. contributions from agricultural lands Klamath Lake and Klamath adjacent to Klamath Lake have been River have been designated water overestimated, and the Klamath quality impaired for several parameters Irrigation Project is probably a net sink including nutrients. Researchers have for nutrients diverted out of Klamath attempted to determine the extent of Lake and Klamath River. Data to agriculture's contributions to nutrient support these assertions are presented. enrichment of surface waters in the Upper Klamath Basin. Two United Introduction States Geological Survey (USGS) Most of the surface waters in the studies focused attention on drainage of Klamath Basin are included in the agricultural lands adjacent to Klamath Oregon Department of Environmental Lake as a significant source of nutrient Quality (DEQ) 303D list as water- loading in the lake. quality limited. While the only criterion A preliminary draft report by the for listing of many streams is Klamath River TMDL committee temperature, based on a preliminary identified the outlet for drainage waters standard of 64°F, Klamath Lake and from the Klamath Irrigation Project to Klamath River are listed for chlorophyll the Klamath River at the Straits Drain as a, dissolved oxygen, un-ionized a point source for nutrient loading. ammonia, and pH. The DEQ is working Preparation of a final TMDL for this toward development of TMDL sub-watershed was tabled pending allocations for Klamath River and Superintendent/Professor and Faculty Research Assistant, respectively, Klamath Experiment Station, Klamath Falls, OR. Klamath Experiment Station 1 KLAMATH BASIN NUTRIENT LOADING Klamath Headwater regions. During the drainage from agricultural lands adjacent Klamath River TMDL planning process, to Klamath Lake implicated these lands discharge from the Klamath Irrigation as major sources of P loading (Miller Project (KIP) at the Straits Drain was and Tash, 1967 and Snyder and Morace, identified as a source of contaminants 1997). Findings from these and other requiring assignment of TMDLs. studies have been used to support Agricultural activities within KIP are acquisition of private lands adjacent to widely thought to be a major source of the lake and conversion to wetlands. nutrient loading to discharge waters. Three major parcels totaling over 15,000 However, multiple water sources and acres have been purchased to date with diversion pathways, the influence of two public funds. About one-half of the wildlife refuges within KIP, and other property is intended for additional water inputs complicate assessment of this storage and the remainder for conversion complex system. to wetlands, which are projected to serve Klamath and Agency lakes as filters to remove nutrients in drainage (referred to as Klamath Lake), the main waters from upland agricultural lands source of water supply for KIP, is in and provide refugial habitat for juvenile advanced stages of eutrophication. The suckers. 80,000-acre lake has an average depth of Studies by the USGS of drainage only 8 feet. High phosphorus (P) content waters from agricultural lands failed to in the lake supports massive blue-green consider nutrient loading in water algae (Aphanizomenonflos-aquae) diverted onto these properties. Over blooms in summer months. The die-off 7,000 acres adjacent to southern portions of algae blooms creates conditions toxic of Klamath Lake are irrigated with water to resident fish, including pH near 10.0, diverted from Klamath Lake in late fall dissolved oxygen levels less than 2.0 and early winter. A long-term study of mg/I, and un-ionized ammonia water quality in Klamath Lake identified concentrations near 1.0 ppm. Fish kills high nutrient content in Howard Bay, the associated with poor water quality in source of irrigation water for over 6,000 1995, 1996, and 1997 depleted stocks of acres of these agricultural lands (Kann shortnose suckers (Chasmistes and Walker, 1999). Nutrient loading to brevirostris) and Lost River suckers KIP from the major diversions out of (Deltistes luxatus), listed as endangered Klamath Lake and Klamath River was under the Endangered Species Act. not documented prior to 1999. The Conditions favorable for algae blooms Klamath Experiment Station (KES) existed before the region was settled; initiated a water-quality monitoring early explorers documented foul water study in 1998 to further define nutrient conditions in Klamath Lake in the loading from natural and agricultural 1840s. sources. Nutrient loads in Klamath Lake and its tributaries have been monitored Objectives and documented (Campbell and Ehinger, 1. Determine total phosphorus (TP) 1993, Campbell et al, 1993, Kann and and total Kjeldahl nitrogen Walker, 1999, Miller and Tash, 1967, (TKN) concentration in natural Sartoris and Sisneros, 1993, and Snyder background sources including and Morace, 1997). USGS studies of major springs and artesian wells; 2 AGRICULTURAL AND NATURAL SOURCES 2. Determine nutrient content of years to determine nutrient irrigation water applied to and concentrations in water applied onto drainage water from agricultural these properties and drainage from them properties adjacent to Klamath into Klamath Lake. During 1999 and Lake; 2000, the diversions from Klamath Lake 3. Determine nutrient loading to the and Klamath River at headworks for the Klamath Irrigation Project at A A, North, and ADY canals were sampled Canal, North Canal, and ADY on an approximate 10- to 14-day Canal diversions. schedule from May through October. Nutrient loading to KIP was calculated Methods using flow data at the diversions Most water samples were reported by the Bureau of Reclamation's collected as grab samples, refrigerated (BOR) Klamath Project Office. immediately, and delivered to the Oregon State University Department of Results Crop and Soil Science Central Most of the samples collected Analytical Laboratory within 24 hours, were analyzed for TP and TKN. or frozen for batch delivery at a later However, P is the limiting nutrient for date. Duplicate samples were frequently blue-green algae and phosphorus drives taken for quality control purposes. On the algae bloom cycle. Subsequent die three occasions in 1999, 24-sample sets off of algae blooms contributes to water were collected with an ISCO automatic quality problems related to pH, dissolved sampler at the A Canal headworks over oxygen, and un-ionized ammonia. Blue- 48-hour periods. Frozen samples were green algae fix nitrogen; during summer kept frozen until analyzed. All samples months, Klamath Lake is a nitrogen were analyzed for unfiltered TP and factory with algae driving the process. TKN using Kjeldahl digestion Phosphorus concentrations of 0.02 to procedures and appropriate control 0.09 ppm are considered adequate to samples. support blue-green algae present in the Sampling sites included several lake (Chu, 1943). springs that are the source of tributaries Springs are the source for several to Klamath Lake. These include the tributaries feeding Klamath Lake. Spring headwaters of Spring Creek, Wood Creek contributes much of the flow in River, Crystal Creek, and Fort Creek. the Williamson River in late summer. Artesian wells sampled are reported to