Potential for Managed Aquifer Recharge to Enhance Fish Habitat in a Regulated River

Managed aquifer recharge (MAR) is typically used to enhance the agricultural water supply but may also be promising to maintain summer streamflows and temperatures for cold-water fish. An existing aquifer model, water temperature data, and analysis of water administration were used to assess potential benefits of MAR to cold-water fisheries in Idaho’s Snake River. This highly-regulated river supports irrigated agriculture worth US $10 billion and recreational trout fisheries worth$100 million. The assessment focused on the Henry’s Fork Snake River, which receives groundwater from recharge incidental to irrigation and from MAR operations 8 km from the river, addressing (1) the quantity and timing of MAR-produced streamflow response, (2) the mechanism through which MAR increases streamflow, (3) whether groundwater inputs decrease the local stream temperature, and (4) the legal and administrative hurdles to using MAR for cold-water fisheries conservation in Idaho. The model estimated a long-term 4%–7% increase in summertime streamflow from annual MAR similar to that conducted in 2019. Water temperature observations confirmed that recharge increased streamflow via aquifer discharge rather than reduction in river losses to the aquifer. In addition, groundwater seeps created summer thermal refugia. Measured summer stream temperature at seeps was within the optimal temperature range for brown trout, averaging 14.4 °C, whereas ambient stream temperature exceeded 19 °C, the stress threshold for brown trout. Implementing MAR for fisheries conservation is challenged by administrative water rules and regulations. Well-developed and trusted water rights and water-transaction systems in Idaho and other western states enable MAR. However, in Idaho, conservation groups are unable to engage directly in water transactions, hampering MAR for fisheries protection

Land use. Technical report 04-007. Project scenario document DDW-015 final as-built

Design documents are a series of technical papers addressing specific design topics on the eastern Snake River Plain Aquifer Model upgrade. Each design document will contain the following information: topic of the design document, how that topic fits into the whole project, which design alternatives were considered and which design alternative is proposed. In draft form, design documents are used to present proposed designs to reviewers. Reviewers are encouraged to submit suggested alternatives and comments to the design document. Reviewers include all members of the Eastern Snake Hydrologic Modeling (ESHM) Committee as well as selected experts outside of the committee. The design document author will consider all suggestions from reviewers, update the draft design document, and submit the design document to the SRPAM Model Upgrade Program Manager. The Program Manager will make a final decision regarding the technical design of the described component. The author will modify the design document and publish the document in its final form in .pdf format on the SRPAM Model Upgrade web site. Final model documentation will include all of the design documents, edited to ensure that the “as-built” condition is appropriately represented. This is the final as-built report for determination of land use and land cover. Recharge calculations depend on the type of land use or land cover. Recharge on irrigated lands was calculated according to the net application of irrigation water from surface sources, the mix of crops, the application method, and the adjusted evapotranspiration rate according to the nearest weather station. Design Documents DDW-001, DDW-002, and DDW-005 through DDW-017 discuss various aspects of this calculation. Recharge on non-irrigated lands was calculated according to procedures presented in Design Document DDW-003. Knowledge of land use or cover was required to determine which calculation method to use, and to apply the appropriate parameters in calculating recharge. There are large differences in recharge rate, depending on the land use. Wetlands that are interconnected with the aquifer may result in a recharge of negative two feet per year or more (Goodell 1988), while other non-irrigated lands may have positive recharge of a few tenths of a foot (Garabedian 1992). Irrigated lands may have positive recharge rates of up to several feet. These large differences in recharge rate make it important to correctly identify the land use within the study area. This paper describes land use maps used in previous studies, the options available for the Eastern Snake Plain Model Enhancement Project, and the methods chosen

Fixed-point and offsite-point recharge and discharge for calibration of Eastern Snake Plain Aquifer Model Version 2, as built; Technical report 2010005, ESPAM2 design document DDW-V2-08 as built ""fixed/offsite""

This report is a Design Document for the calibration of the Eastern Snake Plain Aquifer Model Version 2 (ESPAM 2). Its goals are similar to the goals of Design Documents for ESPAM 1.1: To provide full transparency of modeling data, decisions and calibration; and to seek input from representatives of various stakeholders so that the resulting product can be the best possible technical representation of the physical system (given constraints of time, funding and personnel). It is anticipated that for some topics, a single Design Document will serve these purposes prior to issuance of a final report. For other topics, a draft document will be followed by one or more revisions and a final “as-built” Design Document. Superseded Design Documents will be maintained in a “superseded” file folder on the project Website, and successive versions will be maintained in a “current” folder. This will provide additional documentation of project history and the development of ideas. The ESPAM1.1 recharge tools and algorithms included three mechanisms for representing fluxes between the aquifer that could be represented as singlepoint fluxes into or out of the aquifer. These were the Fixed-point data set, the Scenario-point data set and the Offsite-point data set. The Fixed-point data set (intermediate file extension *.fpt) was designed to represent fluxes that did not enter into any other water-budget calculation. In ESPAM1.1 it was used for various components in the calibration water-budget, as described below. The recharge tools simply added the values to the volume for the appropriate model grid cell and stress period, without performing calculations. Since the MODFLOW code represents all fluxes into or out of the aquifer as if they occurred exactly and only at the center of the model cell, a point data set can reasonably used for any flux that occurs, even if in reality it is spatially distributed. The Scenario-point data set (intermediate file extension *.scn) was also designed to represent fluxes that did not enter into any other water-budget calculations, but was intended specifically for hypothetical fluxes that might be considered in applying the model to scenarios to investigate hydrologic or management questions. Its treatment in the recharge tools and algorithms was identical to the Fixed-point data set, but it was not used in calibration of ESPAM1.1. The Offsite-pumping data set (intermediate file extension *.off) was designed to represent pumping from wells that were distant from the irrigated place of use, where the water was not part of diversion data included in the diversions data sets. The calculation algorithms applied this water as a pumping withdrawal and also included it in canal-seepage and irrigated-lands calculations. The Fixed-point and Offsite-point data sets are retained in ESPAM2 waterbudget calculations, with essentially the same roles and definitions. This design document describes the particular water-budget components represented using these data sets and the details of the calculations

Representation of recharge from canal leakage for calibration of Eastern Snake Plain Aquifer Model Version 2, as built. Technical report 200907. ESPAM2 Design Document DDW-V2-01 As Built ''Canal Recharge''

This report is a Design Document for the calibration of the Eastern Snake Plain Aquifer Model Version 2 (ESPAM 2). Its goals are similar to the goals of Design Documents for ESPAM 1.1: To provide full transparency of modeling data, decisions and calibration; and to seek input from representatives of various stakeholders so that the resulting product can be the best possible technical representation of the physical system (given constraints of time, funding and personnel). It is anticipated that for some topics, a single Design Document will serve these purposes prior to issuance of a final report. For other topics, a draft document will be followed by one or more revisions and a final “as-built” Design Document. Superseded Design Documents will be maintained in a “superseded” file folder on the project Website, and successive versions will be maintained in a “current” folder. This will provide additional documentation of project history and the development of ideas. As described in ESPAM1.1 Design Document DDW-020 (Contor, 2004), water that seeps from the bed of ditches and canals is direct recharge to the aquifer and is unavailable for delivery to farm fields1 (and therefore unavailable for crop evapotranspiration, return flows to the surface-water source, or in-field incidental recharge). Representation of recharge from canal seepage affects the spatial distribution of modeled recharge, but does not affect the mass balance of recharge or the aquifer water budget. This is because if the water were not applied to canal leakage, it would be applied as incidental recharge in the irrigated-lands calculations. If we adopt an On-Farm water budget methodology, representation of the canal seepage will alter the water budget. This Design Document outlines a proposal for treatment of recharge from canal seepage for ESPAM2. It is based on discussions in ESHMC meetings during the winter of 2007-2008 and e-mail communication from members. This is a draft document designed to describe the current proposal and solicit input

Adaptation of the Glover/Balmer/Jenkins analytical stream-depletion methods for no-flow and recharge boundaries; Supplemental files

Supporting information; Six Microsoft Excel worksheets containing raw data, charts, maps. Technical Completion Report 201101

Representation of irrigated lands and source of irrigation water, Eastern Snake Plain Aquifer Model Version 2, as built; Technical report 201002, ESPAM2 design document DDM V2-04 ""Irrigated lands as built""

This report is a Design Document for the calibration of the Eastern Snake Plain Aquifer Model Version 2 (ESPAM 2). Its goals are similar to the goals of Design Documents for ESPAM 1.1: To provide full transparency of modeling data, decisions and calibration; and to seek input from representatives of various stakeholders so that the resulting product can be the best possible technical representation of the physical system (given constraints of time, funding and personnel). It is anticipated that for some topics, a single Design Document will serve these purposes prior to issuance of a final report. For other topics, a draft document will be followed by one or more revisions and a final “as-built” Design Document. Superseded Design Documents will be maintained in a “superseded” file folder on the project Website, and successive versions will be maintained in a “current” folder. This will provide additional documentation of project history and the development of ideas. This Design Document outlines the treatment of irrigated lands and source of irrigation water for ESPAM2. It is an ""as built"" document describing the water budget delivered to calibrators in June 2010, and supercedes the draft Design Document on source of irrigation water (Contor and Pelot, 2008). If additional modifications are made during calibration, this document will be amended

Representation of Soil Type for Calibration of Eastern Snake Plain Aquifer Model Version 2, As Built Revision 1. ESPAM2 Design Document DDW-V2-06 As Built Rev 1 “Soil Type”

During calibration of the Eastern Snake Plain Aquifer Model Version 1.1 (ESPAM1.1), a series of Design Documents were produced to document data sources, conceptual model decisions and calculation methods. These documents served two important purposes; they provided a vehicle to communicate decisions and solicit input from members of the Eastern Snake Hydrologic Modeling Committee (ESHMC) and other interested parties, and they provided far greater detail of particular aspects of the modeling process than would have been possible in a single final report. Many of the Design Documents were presented first in a draft form, then in revised form following input and discussion, and finally in an “as-built” form describing the actual implementation. This report is a Design Document for the calibration of the Eastern Snake Plain Aquifer Model Version 2 (ESPAM2). Its goals are similar to the goals of Design Documents for ESPAM1.1: To provide full transparency of modeling data, decisions and calibration; and to seek input from representatives of various stakeholders so that the resulting product can be the best possible technical representation of the physical system (given constraints of time, funding and personnel). It is anticipated that for some topics, a single Design Document will serve these purposes prior to issuance of a final report. For other topics, a draft document will be followed by one or more revisions and a final “as-built” Design Document. Superseded Design Documents will be maintained in a “superseded” file folder on the project Website, and successive versions will be maintained in a “current” folder. This will provide additional documentation of project history and the development of ideas

Ground water irrigation polygons for recharge calculation. Water budget design document number DDW-009

Design documents are a series of technical papers addressing specific design topics on the eastern Snake River Plain Aquifer Model upgrade. Each design document will contain the following information: topic of the design document, how that topic fits into the whole project, which design alternatives were considered and which design alternative is proposed. In draft form, design documents are used to present proposed designs to reviewers. Reviewers are encouraged to submit suggested alternatives and comments to the design document. Reviewers include all members of the Eastern Snake Hydrologic Modeling (ESHM) Committee as well as selected experts outside of the committee. The design document author will consider all suggestions from reviewers, update the draft design document, and submit the design document to the SRPAM Model Upgrade Program Manager. The Program Manager will make a final decision regarding the technical design of the described component. The author will modify the design document and publish the document in its final form in .pdf format on the SRPAM Model Upgrade web site. Final model documentation will include all of the design documents, edited to ensure that the “as-built” condition is appropriately represented. This design document describes the designation of portions of the study area into “Ground Water Irrigation Polygons” for the purpose of recharge calculation. The withdrawals associated with irrigation from ground water are a negative recharge and will be calculated according to the equation: Net Recharge (ground water) = Precipitation - (ET x Adjustment Factor). The ET adjustment factor will be applied according to the geographic location of the irrigated land being calculated and the application method used to apply water. Adjustment factor and application method parameters for irrigation from ground water will be carried as attributes of the ground water irrigation polygon map. This paper describes the construction of the ground water irrigation polygon map. Parameters for surface water irrigation will be carried as attributes of the aggregated surface water entity map, described in Design Document DDW-008

Monitoring of Egin, Idaho Recharge Experiment. IWRRI Technical completion report 200901

The Egin Lakes are ponds located near a Bureau of Land Management recreational site at the end of the Recharge Canal in southwestern Fremont County, approximately 11 miles west of the town of St. Anthony. A canal extends west of Egin Lakes approximately two more miles to a series of ephemeral ponds referred to in this report as the “West Recharge Area.” Tibbitts Lake is located approximately one mile south of the West Recharge Area. Davis Lake is east of Egin Lakes near the confluence of the Last Chance Canal and the Recharge Canal. The subject area for the 2008 Recharge Experiment and the associated Monitoring Project includes all these locations, and in this report the collective area will be referred to as the “Egin Lakes area.” Between October and December 2008 Fremont-Madison Irrigation District (FMID) diverted storage water from the Henry’s Fork of the Snake River through the St. Anthony, Last Chance and Recharge Canals to the Egin Lakes for a lateseason recharge project. In this pilot project, approximately 4,860 acre-feet were recharged at Egin Lakes, the West Recharge Area, Tibbitts Lake, and the canals solely devoted to the recharge experiment. During the period of the experiment, additional water entered the aquifer in association with canal leakage from diversions for stockwater rights via the St. Anthony and Last Chance Canals. The Idaho Water Resource Board (IWRB) provided funding to compensate FMID for the cost of the storage water and related maintenance and operation costs of the project. In February 2009, a memorandum of understanding was signed between the Idaho Department of Water Resources (IDWR) and the Eastern Idaho Water Rights Coalition (EIWRC) to provide funding for the University of Idaho, acting through the Idaho Water Resources Research Institute (IWRRI) to provide technical assistance for conducting and evaluating recharge monitoring through spring 2009. It is likely this monitoring will continue either through a renewed agreement with IWRRI or involvement of IDWR personnel

Delineation of sprinkler and gravity application systems. Technical report 04-005. Project scenario document DDW-022 final as-built

Design documents are a series of technical papers addressing specific design topics on the eastern Snake River Plain Aquifer Model upgrade. Each design document will contain the following information: topic of the design document, how that topic fits into the whole project, which design alternatives were considered and which design alternative is proposed. In draft form, design documents are used to present proposed designs to reviewers. Reviewers are encouraged to submit suggested alternatives and comments to the design document. Reviewers include all members of the Eastern Snake Hydrologic Modeling (ESHM) Committee as well as selected experts outside of the committee. The design document author will consider all suggestions from reviewers, update the draft design document, and submit the design document to the SRPAM Model Upgrade Program Manager. The Program Manager will make a final decision regarding the technical design of the described component. The author will modify the design document and publish the document in its final form in .pdf format on the SRPAM Model Upgrade web site. Final model documentation will include all of the design documents, edited to ensure that the “as-built” condition is appropriately represented. This Design Document is the final as-built version, reflecting the actual calculated sprinkler percentages for each irrigation entity and ground water polygon. It reflects the revised surface water irrigation entities modified in spring of 2003. The model proposes use of “adjustment factors” to calculate fieldcondition evapotranspiration from predicted evapotranspiration under wellwatered, disease free conditions. Because actual evapotranspiration may be affected by the type of application system used (as well as other factors), and because changes in application system type (e.g. gravity to sprinkler) have occurred during the period of the study, a method for identifying application method and describing changes is required. A secondary reason to identify application method is that the difference between actual irrigated acres and nominal irrigated acres may depend on application method (see Design Document DDW-015)