Klamath Basin Restoration Agreement Off-Project Water Program Evapotranspiration Map for June 2006

Hydrological Information Products for the Off-Project Water Program of the Klamath Basin Restoration Agreement
		
U.S. Geological Survey Open-File Report 2012-1199
U.S. Department of the Interior
		
By Daniel T. Snyder, John C. Risley, and Jonathan V. Haynes
		
Prepared in cooperation with The Klamath Tribes
		
Access complete report at: https://pubs.usgs.gov/of/2012/1199
		
Suggested citation:
Snyder, D.T., Risley, J.C., and Haynes, J.V., 2012, 
Hydrological information products for the Off-Project Water Program of the Klamath Basin Restoration Agreement: 
U.S. Geological Survey Open-File Report 2012–1199, 17 p., 
https://pubs.usgs.gov/of/2012/1199
		
Summary
    The Klamath Basin Restoration Agreement (KBRA) was developed by a diverse group of stakeholders, 
Federal and State resource management agencies, Tribal representatives, and interest groups to provide 
a comprehensive solution to ecological and water-supply issues in the Klamath Basin. The Off-Project 
Water Program (OPWP), one component of the KBRA, has as one of its purposes to permanently provide 
an additional 30,000 acre-feet of water per year on an average annual basis to Upper Klamath Lake through 
“voluntary retirement of water rights or water uses or other means as agreed to by the Klamath Tribes, to 
improve fisheries habitat and also provide for stability of irrigation water deliveries.” The geographic area 
where the water rights could be retired encompasses approximately 1,900 square miles. The OPWP 
area is defined as including the Sprague River drainage, the Sycan River drainage downstream of Sycan 
Marsh, the Wood River drainage, and the Williamson River drainage from Kirk Reef at the southern end 
of Klamath Marsh downstream to the confluence with the Sprague River. Extensive, broad, flat, poorly 
drained uplands, valleys, and wetlands characterize much of the study area. Irrigation is almost entirely 
used for pasture.
    To assist parties involved with decisionmaking and implementation of the OPWP, the U.S. Geological 
Survey (USGS), in cooperation with the Klamath Tribes and other stakeholders, created five hydrological i
nformation products. These products include GIS digital maps and datasets containing spatial information 
on evapotranspiration, subirrigation indicators, water rights, subbasin streamflow statistics, and return-flow 
indicators.
    The evapotranspiration (ET) datasets were created under contract for this study by Evapotranspiration, 
Plus, LLC, of Twin Falls, Idaho. A high-resolution remote sensing technique known as Mapping 
Evapotranspiration at High Resolution and Internalized Calibration (METRIC) was used to create estimates 
of the spatial distribution of ET. The METRIC technique uses thermal infrared Landsat imagery to quantify 
actual evapotranspiration at a 30-meter resolution that can be related to individual irrigated fields. Because 
evaporation uses heat energy, ground surfaces with large ET rates are left cooler as a result of ET than 
ground surfaces that have less ET. As a consequence, irrigated fields appear in the Landsat images as 
cooler than nonirrigated fields. Products produced from this study include total seasonal and total monthly 
(April–October) actual evapotranspiration maps for 2004 (a dry year) and 2006 (a wet year).
    Maps showing indicators of natural subirrigation were also provided by this study. “Subirrigation” as used 
here is the evapotranspiration of shallow groundwater by plants with roots that penetrate to or near the water 
table. Subirrigation often occurs at locations where the water table is at or above the plant rooting depth. 
Natural consumptive use by plants diminishes the benefit of retiring water rights in subirrigated areas. 
Some agricultural production may be possible, however, on subirrigated lands for which water rights are 
retired. Because of the difficulty in precisely mapping and quantifying subirrigation, this study presents 
several sources of spatially mapped data that can be used as indicators of higher subirrigation probability. 
These include the floodplain boundaries defined by stream geomorphology, water-table depth defined in 
Natural Resources Conservation Service (NRCS) soil surveys, and soil rooting depth defined in NRCS 
soil surveys.
    The two water-rights mapping products created in the study were “points of diversion” (POD) and 
“place of use” (POU) for surface-water irrigation rights. To create these maps, all surface-water rights 
data, decrees, certificates, permits, and unadjudicated claims within the entire 1,900 square mile 
study area were aggregated into a common GIS geodatabase. Surface-water irrigation rights within 
a 5-mile buffer of the study area were then selected and identified. The POU area was then totaled 
by water right for primary and supplemental water rights. The maximum annual volume (acre-feet) 
allowed under each water right also was calculated using the POU area and duty (allowable annual 
irrigation application in feet). In cases where a water right has more than one designated POD, the 
total volume for the water right was equally distributed to each POD listed for the water right. Because 
of this, mapped distribution of diversion rates for some rights may differ from actual practice.
    Water-right information in the map products was from digital datasets obtained from the Oregon Water 
Resources Department and was, at the time acquired, the best available compilation of water-right 
information available. Because the completeness and accuracy of the water-right data could not be 
verified, users are encouraged to check directly with the Oregon Water Resources Department where 
specific information on individual rights or locations is essential.
    A dataset containing streamflow statistics for 72 subbasins in the study area was created for the 
study area. The statistics include annual flow durations (5-, 10-, 25-, 50-, and 95-percent exceedances) 
and 7-day, 10-year (7Q10) and 7-day, 2-year (7Q2) low flows, and were computed using regional 
regression equations based on measured streamflow records in the region. Daily streamflow records 
used were adjusted as needed for crop consumptive use; therefore the statistics represent streamflow 
under more natural conditions as though irrigation diversions did not exist. Statistics are provided for 
flow rates resulting from streamflow originating from within the entire drainage area upstream of the 
subbasin pour point (referring to the outlet of the contributing drainage basin). The statistics were 
computed for the purpose of providing decision makers with the ability to estimate streamflow that 
would be expected after water conservation techniques have been implemented or a water right has 
been retired.
    A final product from the study are datasets of indicators of the potential for subsurface return flow 
of irrigation water from agricultural areas to nearby streams. The datasets contain information on factors 
such as proximity to surface-water features, geomorphic floodplain characteristics, and depth to water.
    The digital data, metadata, and example illustrations for the datasets described in this report are 
available on-line from the USGS Water Resources National Spatial Data Infrastructure (NSDI) Node 
Website http://water.usgs.gov/lookup/getgislist or from the U.S. Government website DATA.gov at 
http://www.data.gov with links provided in a Microsoft® Excel® workbook in appendix A.
		
Introduction
		
Program Background
    The Klamath Basin Restoration Agreement (KBRA) was developed by a diverse group of stakeholders, 
Federal and State resource management agencies, Tribal representatives, and interest groups to provide 
a comprehensive solution to ecological and water-supply issues in the basin. The KBRA covers the entire 
Klamath Basin, from headwater areas in southern Oregon and northern California to the Pacific Ocean, and 
addresses a wide range of issues that include hydropower, fisheries, and water resources. The Water 
Resources Program (Part IV of the KBRA) includes a section (16) known as the Off-Project Water Program 
(OPWP) (Klamath Basin Restoration Agreement, 2010, p. 105).
		
Program Goals
    The primary goals of the OPWP include developing an Off-Project Water Settlement to resolve upper 
basin water issues, improve fish habitat, and provide for stability in irrigation deliveries (Klamath Basin 
Restoration Agreement, 2010, p. 105). One of the approaches to achieving these objectives is a water-use 
retirement program. The water-use retirement program is an effort to permanently provide an additional 
30,000 acre-ft of water per year on an average annual basis to Upper Klamath Lake through “voluntary 
retirement of water rights or water uses, or other means as agreed to by the Klamath Tribes, to improve 
fisheries habitat and also provide for stability of irrigation water deliveries” (Klamath Basin Restoration 
Agreement, 2010, p. 105–111).
    The KBRA sets a 24-month window after the “effective date” for development of a proposal for the 
Off-Project Water Settlement. There is interest on the part of the Klamath Watershed Partnership 
(and others) in having a decisionmaking process in place before this time line. To assist parties in 
the OPWP involved with decisionmaking and implementation, the USGS proposed a two-phase 
approach. The first phase, which is described in this report, includes compilation and evaluation of 
relevant existing work and data in the upper basin, and synthesizing that information into a set of five 
hydrological information products. These products include GIS digital maps and datasets containing 
spatial information on evapotranspiration, subirrigation indicators, water rights, subbasin streamflow 
statistics, and return-flow indicators. Should efforts continue, a second phase could be developed to 
implement a monitoring program to evaluate the level of success of the first phase and to address 
additional information needs.
    Understanding the response of streams and groundwater to various land-use changes (such as 
reduction of irrigation or changes in land management) in particular areas is important to maximizing 
the benefits to streams and to Upper Klamath Lake while minimizing the impacts to the agricultural 
community. The hydrology of the region is such that the response to changes in land use will vary 
from place to place. Because of this, the benefit to the stream from a particular change in land or 
water use may be greater in one area than another.
		
Description of Project Area
    The OPWP area is defined in the KBRA as including the Sprague River drainage, the Sycan River 
drainage downstream of Sycan Marsh, the Wood River drainage, and the Williamson River drainage 
from Kirk Reef at the southern end of Klamath Marsh downstream to the confluence with the Sprague 
River, encompassing a total area of approximately 1,900 mi2. Individually, the Sprague, Williamson, 
and Wood Rivers provide about 33, 18, and 16 percent, respectively, of the total inflow to Upper Klamath 
Lake and together account for two-thirds of the total inflow (Hubbard, 1970; Kann and Walker, 1999, table 3). 
Extensive, broad, flat, poorly drained uplands, valleys, and wetlands characterize much of the study area. 
Elevations in the study area range from about 4,100 ft at Upper Klamath Lake to greater than 9,000 ft in the 
Cascade Range. In general, land use in the Williamson River, Sprague River, and Wood River basins varies 
with elevation. At the lowest elevations, adjacent to the major rivers, agricultural lands (primarily irrigated 
pasture) predominate. Rangelands primarily are on the tablelands, benches, and terraces, and forest is 
predominant on the slopes of buttes and mountains. Livestock grazing can occur on irrigated pastureland, 
rangeland, and forestland throughout the study area. Average annual precipitation in the area ranges from 
as low as about 15 in. near Upper Klamath Lake to about 65 in. at Crater Lake with most precipitation 
occurring largely as snow in the fall and winter (Western Regional Climate Center, 2012).
		
Previous Studies and Water Conservation Programs
    Recent studies in the Upper Klamath, Wood River, and Sprague River basins provided a foundation for many 
of the analyses made for this current study. A study of the regional groundwater hydrology of the Upper Klamath 
Basin is presented in Gannett and others (2007) and includes discussions of the hydrogeologic units, hydrologic 
budget, and configuration of the groundwater-flow system. Although the scale of this study is less useful for 
site-specific analysis, it provides a framework for analysis of the hydrology of the OPWP area. Carpenter and 
others (2009) provided a comprehensive analysis of hydrologic and water-quality conditions during restoration 
of the Wood River wetland for 2003–05. In their study, they developed a water budget for the wetland in addition 
to analyzing the mechanics of groundwater and soil moisture storage. Risley and others (2008) developed 
streamflow regression models used in this study to estimate a suite of streamflow statistics in study area 
subbasins. The Natural Resources Conservation Service (2009) presented findings from the Sprague River 
Conservation Effects Assessment Project (CEAP). Their report documented the effects of water conservation 
practices on private irrigated lowlands and uplands using field monitoring and hydrologic computer model 
simulations. Watershed Sciences LCC (2000) conducted a Forward-Looking Infrared (FLIR) survey flown in 
August 1999 for parts of the Upper Klamath Basin that collected both thermal infrared and color videography 
to map stream temperatures that can be used to identify point locations where return flows enter streams.
		
Purpose of This Report
    This report summarizes and provides details on information products created by the USGS for the OPWP 
and its implementation. These products include a set of digital maps in GIS (ArcMap) format that can be used 
together as overlays to help evaluate the relative benefits of reducing or curtailing water use in various areas. 
The maps are not intended to drive the decisionmaking process, but to inform the process. It is envisioned 
that there will be many additional considerations affecting decisions. The digital maps created for this study, 
and described below in more detail, are (1) evapotranspiration, (2) subirrigation indicators, (3) water rights, 
(4) subbasin streamflow statistics, and (5) irrigation return-flow indicators.
		
Access to Data, Metadata, and Example Illustrations
    The digital data, metadata, and example illustrations for the datasets described in this report are available 
on-line from the USGS Water Resources National Spatial Data Infrastructure (NSDI) Node Website (U.S. 
Geological Survey, 2010c) or from the U.S. Government Website DATA.gov (2012). Appendix A consists of a 
Microsoft® Excel® workbook listing each dataset and URL links to the website for the dataset, metadata, and 
example illustrations.
		
Evapotranspiration Mapping
		
Development
    Maps quantifying evapotranspiration (ET) over the entire landscape included in the OPWP were produced under 
contract for this study by Evapotranspiration, Plus, LLC, of Twin Falls, Idaho. The maps were created using a 
high-resolution remote sensing technique first developed by the University of Idaho (Allen and others, 2007a, 2007b). 
The technique known as “Mapping EvapoTranspiration at High Resolution and Internalized Calibration” (METRIC) 
uses Landsat imagery to estimate monthly actual evapotranspiration at 30-m resolution that can be related to 
individual irrigated fields. For the KBRA OPWP study, METRIC was applied to 2 separate years of growing season 
data for which suitable Landsat imagery was available, representing wet (2006) and dry (2004) years. By using 
these 2 years, it was possible to develop a range of likely actual ET over varied climate conditions.
    A small number of irrigated areas in the extreme eastern part of the Sprague River basin were not covered by 
the selected Landsat images used in the METRIC analysis. For these areas, ET was estimated using more 
traditional approaches that used standard ET models and crop coefficients combined with knowledge of crop 
and vegetation types.
    The METRIC procedure uses thermal infrared images from Landsat satellites to quantify ET. Because 
evaporation uses heat energy, ground surfaces with large ET rates are left cooler than ground surfaces that 
have less ET. As a consequence, irrigated fields appear on the images as being cooler than nonirrigated fields. 
The METRIC model is internally calibrated using ground-based reference ET. Both the rate and spatial distribution 
of ET can be efficiently and accurately quantified. A major advantage of using METRIC over conventional methods 
of estimating ET that use crop coefficient curves is that neither the crop development stages nor the specific crop 
type need to be known. In addition to ET, the fraction of reference crop evapotranspiration (ETrF) also is computed 
by METRIC. The alfalfa reference evapotranspiration (ETr), computed using local weather station meteorological 
data, is needed in calibrating METRIC to a specific study area.
    Previous studies have shown that the error between ET estimated from METRIC and measured from lysimeters 
daily and monthly for various crops and land uses in other areas has been from 1 to 4 percent (Allen and others, 
2007b). For the current study, the accuracy of the METRIC ET values for irrigated areas was estimated as 10 
percent for seasonal total ET values and 20 percent for monthly ET values (R.G. Allen, Evapotranspiration, Plus, 
LLC, written commun., 2011). The accuracy of the METRIC ET values for nonirrigated areas was estimated as 20 
percent for seasonal total ET values and 40 percent for monthly ET values (R.G. Allen, Evapotranspiration, Plus, 
LLC, written commun., 2011). These larger values for estimated accuracy relative to other studies are a result of 
a number of factors including the limited availability of Landsat images not impeded by cloud cover or sensor failure 
during the period of interest and the heterogeneity of the study area with regard to vegetation, terrain, and soils. 
When making comparisons between individual areas of actual evapotranspiration, the relative difference between 
the areas likely has a much better accuracy than the accuracy of the absolute values of actual evapotranspiration 
for the individual areas.
    Products produced from this study include total seasonal and total monthly (April–October) actual 
evapotranspiration maps, in millimeters, for 2004 (dry year) and 2006 (wet year) and Landsat image maps for 
April–November 2004 and April–November 2006. Full details regarding Landsat image processing, METRIC 
calibration, and map production for this study are provided in separate reports written by the contractor and 
included in the GIS metadata (Evapotranspiration, Plus, LLC, 2011a, 2011b, 2011c).
		
Subirrigation Indicators 
		
Definition
    “Subirrigation”

Tags: environment, evapotranspiration, geoscientificinformation, inlandwaters, klamath-basin-restoration-agreement, metric, oregon, sprague-river-basin, upper-klamath-basin, usgs-33cdbf27-ac81-4eb9-824f-e994d3889425, williamson-river-basin, wood-river-basin
Organization: Department of the Interior