Walker Lake

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F. WATER FLOW MODEL

This project will develop a decision-support tool to evaluate the effectiveness of proposed acquisitions of water rights from willing sellers to increase water delivery to Walker Lake. The tool's water flow model will include aspects of climate and evaporation from different water sources.

Researchers:

From DRI: Doug Boyle (PI), Division of Hydrologic Sciences (DHS); Greg Pohll (PI), DHS, Gregg Lamorey (Co-I), DHS; Rina Schumer, (Co-I), DHS; Tim Minor (Co-I), Division of Earth and Ecosystems (DEES), Eric McDonald (Co-I), DEES; Rosemary Carroll (Co-I), DHS
From UNR: Scott Tyler (PI), Department of Geologic Sciences and Engineering; Banmali Rawat (Co-I), Department of Electrical Engineering

Updates:

2007: May | June | July | August | September | October | November | December
Current Year: 2008

May 2007:

Development of hydrologic model of headwater areas has begun.  Hydrologic information (e.g., precipitation, temperature, streamflow, etc.) has been identified and obtained from many different agency sources.  The hydrologic information has been input to a hydrologic modeling database and quality assurance and quality control of data has begun. 

GIS information (DEM, soils, vegetation, etc) has been identified and obtained from many different sources.  Watershed boundaries and individual modeling units have been identified from the GIS information for use in the hydrologic model of the headwater areas.

A Sentinel DTS (Distributed Temperature Sensing) unit was leased and arrived on April 21.  This fiber optic cable is used to measure water temperature. Preliminary testing of the unit showed good data readings of temperature resolutions using 30 second averages. Preliminary testing in the lower Truckee River of 500 meters of fiber optic cable showed excellent response to both diurnal heating of the river water, and also the potential for groundwater inflows.

The unit was further tested at a snow energy balance site in the eastern Sierra, where fiber optic cable had been emplaced prior to the winter. The 300-meter fiber was able to clearly show the snow/sediment interface to be a 0 oC and in those areas where the fiber was exposed due to melting, temperatures reached over 35 oC during midday.

In mid May, the Sentinel DTS power supply failed and the instrument was returned for repair. It was returned in one week and is up and running.

Finally, a DTS vendor comparison workshop was planned and scheduled for the week of June 4.  At least four different DTS units will be represented, and collaborators on the project will be testing the units under various environmental conditions. Field trials of the instruments are planned for Lake Tahoe, including a temperature survey to the bottom of Lake Tahoe to test the instrumentation for use in Walker Lake.

June 2007:

DRI report: The following list includes the main accomplishments/progress on Project 2, Sub Tasks 1-5 in the month of June 2007:

  • Development of a hydrologic model of headwater areas is ongoing.  Hydrologic information (e.g., precipitation, temperature, streamflow, etc.) has been identified, obtained and placed in a data file and a quality assurance and quality control analysis is underway.
  • Parameterization of Modular Modeling System – Precipitation-Runoff Modeling System (MMS-PRMS) watershed model, based on GIS information (digital elevation model, soils, vegetation, etc) from many different sources, is underway in the headwater areas.
  • The Project 1 and 2 teams have met several times to discuss the following issues:  identify well locations, retrieve historic well head and pumping data, digitize lithologic well logs, populate hydrologic groundwater database with information from Nevada State Engineer database, and digitize canal locations, water right and land ownership information.  Several more meetings are needed and planned for the near future.

UNR report: A Distributed Temperature Sensor (DTS) vendor comparison workshop was completed during the week of June 4.  Temperature sensing experiments were conducted at UNR, at South Lake Tahoe and two cables were deployed from the center of Lake Tahoe to over 450 meter depth.  The DTS instruments tested showed excellent ability to resolve temperatures to +/-0.05 oC.  Temperature measurements to the bottom of Lake Tahoe showed, for the first time, the clear evidence of internal waves at the thermocline boundary that resulted from storms and high winds the day before the deployment.

July 2007:

The following list includes the main accomplishments/progress on Project 2, Sub Tasks 1-5 in the month of July 2007:

  • Development of hydrologic model of headwater areas is ongoing.  Hydrologic information (e.g., precipitation, temperature, streamflow, etc) has been identified, obtained and placed in a data file.
  • Parameterization, testing, and evaluation of a Modular Modeling System – Precipitation-Runoff Modeling System (MMS-PRMS) watershed model of the headwater areas, based on GIS information (digital elevation model, soils, vegetation, etc) from many different sources, is underway.
  • The Project 1 and 2 teams have met several times to discuss the following issues:  identify well locations, retrieve historic well head and pumping data, digitize over 2000 lithologic well logs, populate a hydrologic groundwater database with information from the Nevada State Engineer in an Excel database, and digitize canal locations.  Several more meetings are needed and planned for the near future.  The next Project 1 and 2 team meeting is scheduled for Tuesday 7 August 2007 to discuss scenario development and current progress on development of GIS spatial information acquisition and availability of hydrologic time series data sets.

Based on the lithologic information from the groundwater well logs, a conceptual groundwater model is being developed for the entire demand side of the system (mountain front to Walker Lake).  This effort will be closely coordinated with the USGS effort to develop a conceptual groundwater model of the immediate Walker Lake area. A field visit of the watershed is planned for 15 August 2007.

A Sensornet Distributed Temperature Sensor (DTS) unit was ordered during the month of July and will be available for use, thanks to an expedited manufacturing schedule, by the end of August, 2007.

August 2007:

Development of hydrologic model of headwater areas is ongoing.  Parameterization, testing and evaluation of Modular Modeling System – Precipitation-Runoff Modeling System (MMS-PRMS) watershed model of the headwater areas, based on GIS information (digital elevation model, soils, vegetation, etc) from many different sources, is underway.

The teams involved with this task have met several times to discuss several issues, including: identifying well locations, retrieving historic well head and pumping data, digitizing more than 2,000 lithologic well logs, populating hydrologic groundwater database with information from the Nevada State Engineer into an Excel database, and digitizing canal locations.  The digitized well log database is complete except for the coordinates of some of the wells are still being determined.  Several more meetings are needed and planned for the near future to discuss scenario development and current progress on development of GIS spatial information acquisition and availability of hydrologic time series data sets.

Based on the lithologic information from the groundwater well logs and a recent (Aug. 15) field visit, a conceptual groundwater model has been developed for the entire demand side of the system (mountain front to Walker Lake).  This effort will be closely coordinated with the USGS effort to develop a conceptual groundwater model of the immediate Walker Lake area.

The team also reported that field portable Distributed Temperature Sensor (DTS) instrument system was designed and is under construction.  The deployment equipment will include a climate controlled trailer and solar power (with generator backup). The trailer system is expected to be ready to receive the DTS system in late September.

During August, DTS short course notes and lectures were prepared. In September, a PI will participate in a National Science Foundation-sponsored workshop on DTS at Oregon State University.

Abstracts for two DTS related presentations were submitted to the American Geophysical Union.

Highlight of the month

Field visit of Walker Lake watershed was made on Aug. 15. In addition, the results of DTS testing in June were fully processed and revealed remarkable details of the thermal profiles at Lake Tahoe during the deployment on June 7, including oscillations of the thermocline at a depth of 40 meters resulting from strong winds over several days previous to the deployment.  These internal waves in the thermocline are critical to nutrient and energy dynamics of the lake and a full deployment in Walker Lake is now planned to assist in lake modeling and fisheries monitoring.

September 2007:

  • Our field portable DTS instrument system is under construction.  The deployment equipment includes a climate controlled trailer and solar power (with generator backup).
  • The system for deploying fiber optic cable to support Project 5 (Soils and Alternative Agriculture) is under construction and it is anticipated that the fiber will be installed in mid to late October. 
  • Development of hydrologic model of headwater areas is ongoing.
  • Parameterization, testing, and evaluation of a Modular Modeling System – Precipitation-Runoff Modeling System (MMS-PRMS) watershed model of the headwater areas, based on GIS information (digital elevation model, soils, vegetation, etc) from many different sources, is underway.
  • The Task 1 and 2 teams have met several times to discuss the following issues:  identify well locations, retrieve historic well head and pumping data, digitize over 2000 lithologic well logs, populate hydrologic groundwater database with information from Nevada State Engineer into Excel database, and digitize canal locations.  The digitized well log database is complete except for the coordinates of some of the wells which are still being determined.  Several more meetings are needed and planned for the near future to discuss scenario development and current progress on development of GIS spatial information acquisition and availability of hydrologic time series data sets.
  • Based on the lithologic information from the groundwater well logs and a recent (15 August 2007) field visit, a conceptual groundwater model has been developed for the entire demand side of the system (mountain front to Walker Lake).  This effort will be closely coordinated with the USGS effort to develop a conceptual groundwater model of the immediate Walker Lake area.

Highlight of the month
A DTS Workshop, sponsored by the National Science Foundation, was conducted at Oregon State University’s H.J. Andrews Experimental Forest in mid September. PI Tyler was one of four instructors for the class and DTS systems were deployed and tested in a variety of stream environments. A new groundwater/surface water exchange experimental design, using ice as a tracer, was tested and proved successful for moderate flow streams. Figure 1 shows the cold “plume” of stream water moving downstream from the injection site. We anticipate using this method to estimate seepage losses from irrigation ditches and canals in the Walker Basin.

Graph

Figure 1. Time series of temperatures from an ice injection test in Watershed W3 of the H.J. Andrews Experimental Forest. The green colored plume originating at ~800 meters down the stream can be seen to slowly move upward and to the right in the plot, which corresponds to the slow migration downstream of the cold water injection.

October 2007:

A DTS survey was completed in the upper Truckee River for testing purposes and in conjunction with two University of Nevada courses.  Approximately 500 meters of river were instrumented with both DTS cable and piezometers to measure stream-groundwater interaction.  The results revealed a strong groundwater inflow along one bank of the river, in spite of elevated river flows that would normally have masked the inflows.  Results from the groundwater piezometers confirmed the location of upwelling groundwater.

Significant progress was made on the tool development to install DTS fiber beneath the alternative agriculture field sites (Project 5) to measure seedbed temperature.  Field trials of an automated fiber installation tool, towed behind a tractor, were successfully completed at the University’s Main Station Farm. We anticipate installation of 2 km of fiber at the alternative agriculture field sites to begin in the second week of November as we are waiting on delivery of field dedicated fiber.

The development, testing, and evaluation of the hydrologic models of the headwater areas and the groundwater are all ongoing.

November 2007:

Over 1.5 miles of fiber optic cable have been installed in the Walker Basin to monitor soil temperature and soil moisture in research plots to develop alternative agriculture and alternative watering strategies. Fiber was installed in the subsurface using a system design at UNR to safely bury the fiber at a fixed depth across the field plots. Figure 1 shows the installation behind one of the UNR tractors at the 5C Ranch Experimental site.

Fiber optic stream temperature sensing was tested in the Truckee River in late November, and we have scheduled stream and Walker Lake temperature runs in collaboration with colleagues from the U.S. Geological Survey in mid January.

Some spatial information on the ditches and drains for Mason Valley was made available to the Project 2 team at the end of November.  This information is currently being used to develop the conceptual model for the Mason Valley.  We expect the remainder of the Mason Valley information from the Project 1 team sometime in January with the spatial information for Smith Valley to follow.

The conceptual model development of the coupled surface and groundwater models of Mason is almost complete.  The team decided to use the new USGS GSFLOW model to simulate the movement of water throughout the Mason and Smith Valleys.  A steady state Modflow model has been developed for Mason Valley and is currently being tested and improved to accurately simulate the groundwater system over a historic time period. The development, testing, and evaluation of the hydrologic models of the headwater areas and Mason Valley are all ongoing.

Tractor and researchers

Project 2.  Photograph of fiber optic cable being installed at a depth of 15 cm (6”) below the soil surface at the 5C Experimental Site. Over 3,000 feet of fiber was installed at this site.

December 2007:

Planning for Walker Lake Distributed Temperature sensing deployment in mid-January completed with the U.S. Geological Survey.

Highlight of the month
The fiber optic deployment at the Alternative Agriculture study plots (5C Ranch and Wildlife Management area) were wrapped, including rolling of the fields and final cable connections. A 72-hour field test is planned for January.

Three presentations on the use of Distributed Temperature Sensing for environmental hydrology were made by project personnel at the American Geophysical Union's Annual meeting in San Francisco during December.

Spatial information on the ditches and drains for Mason Valley continued to become available to the Project 2 team in December. This information is being used to develop the conceptual model for the Mason Valley. We expect the remainder of the Mason Valley information from the Project 1 team sometime in January with the spatial information for Smith Valley to follow. The digital elevation model (DEM) is being used along with the available stream and ditch information to model ground water in the Mason Valley. The steady state model developed for Mason Valley is currently being tested and improved to accurately simulate the groundwater system over a historic time period. The development, testing, and evaluation of the hydrologic models of the headwater areas and Mason Valley are all ongoing.

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