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• 1601. [Image] Oregon Plan for Salmon and Watersheds biennial report, 2005-2007

  	The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing ...
  	Citation × Citation Citation Abstract Copy Title: Oregon Plan for Salmon and Watersheds biennial report, 2005-2007 Author: Oregon Watershed Enhancement Board Year: 2006, 2007 The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing efforts of people throughout Oregon to improve and protect clean water and recover and maintain healthy populations offish and wildlife in our watersheds. The Oregon Plan is unique because it engages communities in the restoration and long-term stewardship of their watersheds. This extraordinary effort encourages local partnerships and voluntary actions to improve the conditions of our watersheds. Over the years, these actions have made Oregon a national leader in local cooperative conservation. This report collects project and condition data, voluntary private lands restoration information, and agency program accomplishments under the Oregon Plan. Consistent with the past two reports, this document continues to provide specific data on each of the state's fifteen reporting basins. A new element to this report is the inclusion of stories about the people, partnerships, and on-the-ground projects that are benefiting watersheds and communities across the state. Thanks to the many Oregon Plan partners who contributed to this report. Thomas M. Byler Executive Director Oregon Watershed Enhancement Board Title: Oregon Plan for Salmon and Watersheds biennial report, 2005-2007 Author: Oregon Watershed Enhancement Board Year: 2006, 2007 The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing efforts of people throughout Oregon to improve and protect clean water and recover and maintain healthy populations offish and wildlife in our watersheds. The Oregon Plan is unique because it engages communities in the restoration and long-term stewardship of their watersheds. This extraordinary effort encourages local partnerships and voluntary actions to improve the conditions of our watersheds. Over the years, these actions have made Oregon a national leader in local cooperative conservation. This report collects project and condition data, voluntary private lands restoration information, and agency program accomplishments under the Oregon Plan. Consistent with the past two reports, this document continues to provide specific data on each of the state's fifteen reporting basins. A new element to this report is the inclusion of stories about the people, partnerships, and on-the-ground projects that are benefiting watersheds and communities across the state. Thanks to the many Oregon Plan partners who contributed to this report. Thomas M. Byler Executive Director Oregon Watershed Enhancement Board Close

• 1602. [Image] Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005

  	Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, ...
  	Citation × Citation Citation Abstract Copy Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Close

• 1603. [Image] Federal Register - Endangered and Threatened Wildlife and Plants; Review of Native Species That are Candidates or Proposed for Listing as Endangered or Threatened

  	In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates ...
  	Citation × Citation Citation Abstract Copy Title: Federal Register - Endangered and Threatened Wildlife and Plants; Review of Native Species That are Candidates or Proposed for Listing as Endangered or Threatened Year: 2005, 2008 In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates or have proposed for addition to the Lists of Endangered and Threatened Wildlife and Plants under the Endangered Species Act of 1973, as amended. Identification of candidate species can assist environmental planning efforts by providing advance notice of potential listings, allowing resource managers to alleviate threats and thereby possibly remove the need to list species as endangered or threatened. Even if we subsequently list a candidate species, the early notice provided here could result in more options for species management and recovery by prompting candidate conservation measures to alleviate threats to the species. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Forms (species assessment forms, previously called candidate forms) for each candidate species. We request additional status information that may be available for the 286 candidate species. We will consider this information in preparing listing documents and future revisions to the notice of review, as it will help us in monitoring changes in the status of candidate species and in management for conserving them. Previous Notices of Review The Act directed the Secretary of the Smithsonian Institution to prepare a report on endangered and threatened plant species, which was published as House Document No. 94-51 Title: Federal Register - Endangered and Threatened Wildlife and Plants; Review of Native Species That are Candidates or Proposed for Listing as Endangered or Threatened Year: 2005, 2008 In this Candidate Notice of Review (CNOR), we, the U.S. Fish and Wildlife Service (Service), present an updated list of plant and animal species native to the United States that we regard as candidates or have proposed for addition to the Lists of Endangered and Threatened Wildlife and Plants under the Endangered Species Act of 1973, as amended. Identification of candidate species can assist environmental planning efforts by providing advance notice of potential listings, allowing resource managers to alleviate threats and thereby possibly remove the need to list species as endangered or threatened. Even if we subsequently list a candidate species, the early notice provided here could result in more options for species management and recovery by prompting candidate conservation measures to alleviate threats to the species. Additional material that we relied on is available in the Species Assessment and Listing Priority Assignment Forms (species assessment forms, previously called candidate forms) for each candidate species. We request additional status information that may be available for the 286 candidate species. We will consider this information in preparing listing documents and future revisions to the notice of review, as it will help us in monitoring changes in the status of candidate species and in management for conserving them. Previous Notices of Review The Act directed the Secretary of the Smithsonian Institution to prepare a report on endangered and threatened plant species, which was published as House Document No. 94-51 Close

• 1604. [Image] Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon

  	Two maps digitized separately; Includes bibliographical references (p. 44-49)
  	Citation × Citation Citation Abstract Copy Title: Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon Author: Snyder, Daniel T. Year: 1997, 2005, 2004 Two maps digitized separately; Includes bibliographical references (p. 44-49) Title: Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon Author: Snyder, Daniel T. Year: 1997, 2005, 2004 Two maps digitized separately; Includes bibliographical references (p. 44-49) Close

• 1605. [Image] Water availability for Oregon's rivers and streams: Volume 2; Technical guide and appendixes

  	Title from cover; "May 1991"
  	Citation × Citation Citation Abstract Copy Title: Water availability for Oregon's rivers and streams: Volume 2; Technical guide and appendixes Author: Robison, E. George Year: 1991, 2004 Title from cover; "May 1991" Title: Water availability for Oregon's rivers and streams: Volume 2; Technical guide and appendixes Author: Robison, E. George Year: 1991, 2004 Title from cover; "May 1991" Close

• 1606. [Image] Farming practices and water quality in the Upper Klamath Basin : final report to the California State Water Resources Control Board : 205j program

  	Summary The Upper Klamath Basin (UKB) is a high desert region straddling the California-Oregon border east of the Cascade Range. Irrigation and other agricultural practices in the U. S. Bureau of Reclamation's ...
  	Citation × Citation Citation Abstract Copy Title: Farming practices and water quality in the Upper Klamath Basin : final report to the California State Water Resources Control Board : 205j program Author: Danosky, Earl; Kaffka, Stephen Year: 2002, 2007, 2006 Summary The Upper Klamath Basin (UKB) is a high desert region straddling the California-Oregon border east of the Cascade Range. Irrigation and other agricultural practices in the U. S. Bureau of Reclamation's Klamath Project may result in impaired surface water quality, reducing its use for wildlife and fish in important national wildlife refuges that receive drainage water from farms, and in the Klamath River. By 2004, a system of total maximum daily loads (TMDL) for nutrients must be established for the Klamath River. To investigate the relationships among agricultural practices and surface water quality in the Upper Klamath Basin, a two year reconnaissance survey of surface water and agricultural tile drain locations, focusing on nitrogen and phosphorus concentrations and mass transfers was conducted. Data was collected at 18 surface locations and 10 tile drain locations. Triplicate samples were taken every ten days during the growing season (April through October) and one or two times a month during the remainder of the months, depending on opportunity. No samples were taken from tile drains during the winter months because there was no irrigation and drainage during that period. Water samples were analyzed for phosphorus (total P, soluble reactive P, total filterable P, and particulate P) and nitrogen (total N, soluble N, Soluble organic N, total filterable N, particulate N, and ammonia N), temperature, pH and electrical conductivity, a measure of salinity or total dissolved solids. Analyses of data, including data quality, estimates of the transfer of nutrients in surface waters in the region, and hypotheses about the relationship between agriculture and water quality are reported. 1. The salt and nutrient content of surface waters increases nearly threefold as water moves through the watershed from the Lost River and J canal diversion to the Klamath Straits Drain. Mean ECW levels in input waters at the J canal diversion were approximately 250 \iS cm1, while water sampled at the D pump increased to 600 ^S cm"1 on average over the sample period. By the time water reenters the Klamath River, salt concentrations have increased to approximately 700 jaS cm1. 2. The ECW values observed in subsurface tile drains were higher on average than in input waters and surface waters elsewhere in the region, especially in the Lease Lands area of the Tulelake Irrigation District (TID). ECW values averaged approximately 2,500 ^S cm"1 . Recycling irrigation water through soils in the TID increases the salinity of the water, especially by the time it reaches and is reused in the Lease Lands area of the Tulelake National Wildlife Refuge (TLNWR). Soils in this part of the Klamath Project area are naturally high in salt. 3. Water temperatures in agricultural subsurface tile drains were significantly lower than surface water temperatures during the growing season when tile drains were active. pH values in tile drains were lower than surface water values. The temperature and pH of tile drains does not influence surface water values. 1. 4. For total phosphorus (TP) input waters at the J canal irrigation diversion for the TED averaged approximately 0.27 mg L1 for the two years reported. Water leaving the Tulelake Sumps at the D pump increases to 0.33 mg L1. Water leaving the Lower Klamath National Wildlife Refuge (LKNWR) sampled at the start of the Klamath Straits Drain, averaged 0.33 mg L1, similar to those at the D pump. TP increased further to 0.40 mg L"1 a the end of the Klamath Straits Drain. The overall increase in P concentration in surface waters was much less than for salt, suggesting that processes other than simple enrichment are occurring, particularly those associated with the exchange of sedimentary P and aquatic plant species. TN increases from 2.3 mg L"1 to 4.0 mg L1 over the same pathway. Atomic ratios (TN:TP) of surface water samples remain constant at approximately 10:1 throughout the system, suggesting that the amount of sediment and other small particulate matter in surface waters affects the values observed. The amount of sediment is influenced in part by the agitation of surface water as it passes through pumps and over weirs. 5. The average seasonal TP value in tile drains beneath farm fields is approximately 0.34 mg L"1 . While average total P values in subsurface tile drains were not different from those found at the D pump and the LKNWR outlet, the range in values was great (0.1 to 0.8 mg L1). Similarly, high NO3 -N values were observed at times in tile drains. Very high values in tile drains lead to the inference that some fertilizer N and P is lost in drainage water, combined with nutrients derived from decaying soil organic matter. The amount estimated as lost is much less than the amount of surplus fertilizer P applied and the amount of P surmised to be mineralized from decaying soil organic matter. P from fertilizer and decaying organic matter appears to be accumulating in soils and lake sediments in the region. 6. Ammonia N concentrations are at or below the limit of detection in subsurface agricultural tile lines and one to two orders of magnitude below the values observed in surface soils. Un ionized ammonia increases with temperature. Values above 0.25 mg L1 were observed in late summer at several locations. 7. Some leaching of soluble salts and nutrients is unavoidable when crops are irrigated. P fertilizer is applied at rates higher than crop removal, while fertilizer n is applied at rates less than crop removal. Reduced fertilizer use can help bring P inputs and outputs into balance and may reduce further any avoidable losses of P. This objective should be the subject of an agronomic research program in the region. 8. Surface waters entering the TDD, the TLNWR, and the LKNWR are already enriched with N and P. It seems unlikely that reducing N and P losses from farming in the TID, if possible, would influence surface water quality sufficiently to make them significantly less eutrophic. For P, the hypothesized threshold concentration limiting algae growth in fresh waters is 5 to 25 times smaller than the values observed in waters entering the TID for irrigation use. The addition of 1. nutrients from agriculture probably does not influence significantly surface water quality in the region. Wetland sediments, large amounts of organic matter in soils, and water introduced for irrigation contain essentially unlimited amounts of nutrients for aquatic plant growth. It is not clear how this circumstance could be changed under any reasonable time frame, if ever. 9. Using a TMDL approach may not result in reduced amounts of nutrients returned to the Klamath River because wetlands and farming practices in the southern portion of the Klamath Project result in the net removal of nutrients from the waters diverted for irrigation on a yearly basis, compared to allowing the same amount of water simply to flow down the river unused. Because of large errors of estimation for the amounts of water transferred, combined with smaller errors associated with estimating nutrient concentrations in water samples, and with year to year climate variation, TMDLs may not be an effective or efficient means of reducing nutrients in return flows to the Klamath River. Rational confidence limits for TMDLs may have to be too broad to be effective. Recycling of some drainage water for irrigation would reduce the amount of nutrients returned to the river more effectively than implementing a TMDL program. Title: Farming practices and water quality in the Upper Klamath Basin : final report to the California State Water Resources Control Board : 205j program Author: Danosky, Earl; Kaffka, Stephen Year: 2002, 2007, 2006 Summary The Upper Klamath Basin (UKB) is a high desert region straddling the California-Oregon border east of the Cascade Range. Irrigation and other agricultural practices in the U. S. Bureau of Reclamation's Klamath Project may result in impaired surface water quality, reducing its use for wildlife and fish in important national wildlife refuges that receive drainage water from farms, and in the Klamath River. By 2004, a system of total maximum daily loads (TMDL) for nutrients must be established for the Klamath River. To investigate the relationships among agricultural practices and surface water quality in the Upper Klamath Basin, a two year reconnaissance survey of surface water and agricultural tile drain locations, focusing on nitrogen and phosphorus concentrations and mass transfers was conducted. Data was collected at 18 surface locations and 10 tile drain locations. Triplicate samples were taken every ten days during the growing season (April through October) and one or two times a month during the remainder of the months, depending on opportunity. No samples were taken from tile drains during the winter months because there was no irrigation and drainage during that period. Water samples were analyzed for phosphorus (total P, soluble reactive P, total filterable P, and particulate P) and nitrogen (total N, soluble N, Soluble organic N, total filterable N, particulate N, and ammonia N), temperature, pH and electrical conductivity, a measure of salinity or total dissolved solids. Analyses of data, including data quality, estimates of the transfer of nutrients in surface waters in the region, and hypotheses about the relationship between agriculture and water quality are reported. 1. The salt and nutrient content of surface waters increases nearly threefold as water moves through the watershed from the Lost River and J canal diversion to the Klamath Straits Drain. Mean ECW levels in input waters at the J canal diversion were approximately 250 \iS cm1, while water sampled at the D pump increased to 600 ^S cm"1 on average over the sample period. By the time water reenters the Klamath River, salt concentrations have increased to approximately 700 jaS cm1. 2. The ECW values observed in subsurface tile drains were higher on average than in input waters and surface waters elsewhere in the region, especially in the Lease Lands area of the Tulelake Irrigation District (TID). ECW values averaged approximately 2,500 ^S cm"1 . Recycling irrigation water through soils in the TID increases the salinity of the water, especially by the time it reaches and is reused in the Lease Lands area of the Tulelake National Wildlife Refuge (TLNWR). Soils in this part of the Klamath Project area are naturally high in salt. 3. Water temperatures in agricultural subsurface tile drains were significantly lower than surface water temperatures during the growing season when tile drains were active. pH values in tile drains were lower than surface water values. The temperature and pH of tile drains does not influence surface water values. 1. 4. For total phosphorus (TP) input waters at the J canal irrigation diversion for the TED averaged approximately 0.27 mg L1 for the two years reported. Water leaving the Tulelake Sumps at the D pump increases to 0.33 mg L1. Water leaving the Lower Klamath National Wildlife Refuge (LKNWR) sampled at the start of the Klamath Straits Drain, averaged 0.33 mg L1, similar to those at the D pump. TP increased further to 0.40 mg L"1 a the end of the Klamath Straits Drain. The overall increase in P concentration in surface waters was much less than for salt, suggesting that processes other than simple enrichment are occurring, particularly those associated with the exchange of sedimentary P and aquatic plant species. TN increases from 2.3 mg L"1 to 4.0 mg L1 over the same pathway. Atomic ratios (TN:TP) of surface water samples remain constant at approximately 10:1 throughout the system, suggesting that the amount of sediment and other small particulate matter in surface waters affects the values observed. The amount of sediment is influenced in part by the agitation of surface water as it passes through pumps and over weirs. 5. The average seasonal TP value in tile drains beneath farm fields is approximately 0.34 mg L"1 . While average total P values in subsurface tile drains were not different from those found at the D pump and the LKNWR outlet, the range in values was great (0.1 to 0.8 mg L1). Similarly, high NO3 -N values were observed at times in tile drains. Very high values in tile drains lead to the inference that some fertilizer N and P is lost in drainage water, combined with nutrients derived from decaying soil organic matter. The amount estimated as lost is much less than the amount of surplus fertilizer P applied and the amount of P surmised to be mineralized from decaying soil organic matter. P from fertilizer and decaying organic matter appears to be accumulating in soils and lake sediments in the region. 6. Ammonia N concentrations are at or below the limit of detection in subsurface agricultural tile lines and one to two orders of magnitude below the values observed in surface soils. Un ionized ammonia increases with temperature. Values above 0.25 mg L1 were observed in late summer at several locations. 7. Some leaching of soluble salts and nutrients is unavoidable when crops are irrigated. P fertilizer is applied at rates higher than crop removal, while fertilizer n is applied at rates less than crop removal. Reduced fertilizer use can help bring P inputs and outputs into balance and may reduce further any avoidable losses of P. This objective should be the subject of an agronomic research program in the region. 8. Surface waters entering the TDD, the TLNWR, and the LKNWR are already enriched with N and P. It seems unlikely that reducing N and P losses from farming in the TID, if possible, would influence surface water quality sufficiently to make them significantly less eutrophic. For P, the hypothesized threshold concentration limiting algae growth in fresh waters is 5 to 25 times smaller than the values observed in waters entering the TID for irrigation use. The addition of 1. nutrients from agriculture probably does not influence significantly surface water quality in the region. Wetland sediments, large amounts of organic matter in soils, and water introduced for irrigation contain essentially unlimited amounts of nutrients for aquatic plant growth. It is not clear how this circumstance could be changed under any reasonable time frame, if ever. 9. Using a TMDL approach may not result in reduced amounts of nutrients returned to the Klamath River because wetlands and farming practices in the southern portion of the Klamath Project result in the net removal of nutrients from the waters diverted for irrigation on a yearly basis, compared to allowing the same amount of water simply to flow down the river unused. Because of large errors of estimation for the amounts of water transferred, combined with smaller errors associated with estimating nutrient concentrations in water samples, and with year to year climate variation, TMDLs may not be an effective or efficient means of reducing nutrients in return flows to the Klamath River. Rational confidence limits for TMDLs may have to be too broad to be effective. Recycling of some drainage water for irrigation would reduce the amount of nutrients returned to the river more effectively than implementing a TMDL program. Close

• 1607. [Image] Official annual, Medford District, Ninth Corps Area, Civilian Conservation Corps.

  	Annual; Description based on: 1938 issue; Cover title
  	Citation × Citation Citation Abstract Copy Title: Official annual, Medford District, Ninth Corps Area, Civilian Conservation Corps. Author: Civilian Conservation Corps (U.S.). Medford District Year: 1938, 2008, 2006 Annual; Description based on: 1938 issue; Cover title Title: Official annual, Medford District, Ninth Corps Area, Civilian Conservation Corps. Author: Civilian Conservation Corps (U.S.). Medford District Year: 1938, 2008, 2006 Annual; Description based on: 1938 issue; Cover title Close