CO-LOCATING IRRIGATION AND SOLAR POWER INFRASTRUCTURE TO BOLSTER FRESHWATER SUSTAINABILITY IN A SEMI-ARID AGRICULTURAL REGION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1030437
• Grant No.: 2023-67020-39704
• Cumulative Award Amt.: $299,296.00
• Proposal No.: 2022-09294
• Project Start Date: Jun 1, 2023
• Project End Date: May 31, 2026
• Grant Year: 2023
• Program Code: [A1411]- Foundational Program: Agricultural Water Science

Recipient Organization
UNIVERSITY OF TEXAS-PAN AMERICAN
1201 W. UNIVERSITY DRIVE
EDINBURG,TX 78539-2999

Performing Department
(N/A)

Non Technical Summary
This project aims to improve irrigation water conservation in dry-climate agricultural regions. To achieve this goal, the team will investigate the use of solar panels to suppress evaporation from irrigation storage and conveyance systems. The focus will be on the Rio Grande Valley (RGV) of Texas, an underserved agricultural region that is home to >1.3 million people. Irrigation is critical to sustain agricultural productivity andaccounts for ~80% of total freshwater withdrawals in the semi-arid RGV.Yet high irrigation needs, climate change and a burgeoning population growth are straining the region's water resources.Through this Seed Grant, the project team will develop a preliminary analysis of opportunities, benefits and challenges associated with covering irrigation reservoirs, human-made ditches, and natural channels (i.e., ancient secondary river channels) with solar panels in the RGV. This includes mapping and consolidating data on irrigation storage and conveyance systems, developing scenarios with solar energy generation potential and limitations, and assessing irrigation water losses and quality to determine potential co-benefits from irrigation-solar co-location. The outcomes of this Seed Grant will position the team to pursue follow-on funding for a larger project that will further evaluate specific co-benefits, engages stakeholders, and encompasses logistical, social, and economic dimensions of co-locating irrigation infrastructure and solar power.

Animal Health Component

80%

Research Effort Categories

Basic

20%

Applied

80%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
111	0210	2050	30%
111	0210	1190	30%
111	0210	2020	40%

Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
2020 - Engineering; 2050 - Hydrology; 1190 - Limnology;

Keywords

hydrology

limnology

renewable energy

sustainability

water conservation

water-energy-food nexus

Goals / Objectives
To support our long-term, follow-on goal of leveraging solar power to improve irrigation water sustainability while promoting decarbonization in the semi-arid Rio Grande Valley, we set four specific aims for this Seed Grant:Consolidate data on irrigation storage and conveyance systems.Assess current water losses from uncovered irrigation storage and conveyance systems.Evaluate the water quality of uncovered irrigation storage and conveyance systems.Determine opportunities and challenges for co-locating solar power and irrigation infrastructure.

Project Methods
Geospatial analyses.We will map the total surface area and volume of irrigation storage and open-channel systems in the RGV. We will consolidate existing geospatial datasets, such as those made publicly available by the Irrigation District Engineering and Assistance program of the Texas A&M Agrilife Extension Service, which will be complemented by a new, updated set of geospatial analyses.Specifically, we will classify and map the extent of all types of irrigation systems that are directly subject to evaporative losses, including artificial (irrigation ponds and reservoirs) and natural (resacas) storage and conveyance infrastructure. We will also synthesize data on water withdrawals for irrigation and other purposes in the RGV, which are available from USGS, and consolidate available data from the >25 irrigation districts of the region, as well as public utility companies. In addition to mapping the spatial footprint of irrigation systems, these data will allow us to analyze trends in irrigation water use over time and run projections into the future.Water losses. We propose to evaluate which of two broad approaches to estimating hydrologic losses in irrigation systems will yield the most cost-effective and useful data that could be extrapolated across the RGV. The first approach focuses on the feasibility and effectiveness of additional gages designed to provide point estimates of evaporation (using evaporation pans) and infiltration/seepage (using infiltrometers) at hydrologically distinct areas of the RGV's irrigation network--including human-made and natural reservoirs and conveyance mechanisms (irrigation canals and resacas). The second approach would center on monitoring these systems from a small-scale, precise water-balance approach. This method might yield sufficiently useful estimates of hydrologic abstractions as a combined, single parameter at a significantly lower cost than an extensive network. This second approach would focus on candidate testbeds among the various reservoirs, human-made ditches, and natural irrigation conveyance systems across the RGV. We will use evaporation pans and infiltrometers to take field measurements while evaluating these two approaches. We will compare field measurements with modeled evaporation rates computed through well-established equations that use climatological input data, such as solar radiation, air temperature, water vapor pressure, wind speed, and elevation.Water quality.We will consolidate existing data from irrigation districts and public utility companies and conduct additional field work to measure water quality parameters in irrigation reservoirs, open canals, and resacas. We are particularly interested in determining the trophic status of irrigation water in the RGV. To create a baseline for follow-on studies and funding, we will evaluate the water quality of irrigation reservoirs, open canals, and resacas. We will bi-monthlysample 20-30 sites during the 2-year period of this Seed Grant. We will use a multiparameter sonde to measure chlorophyll-a, turbidity, pH, conductivity, temperature, and dissolved oxygen. We will also grab samples to measure nitrate, ammonia and, ortophosphate, andtotal phosphorus using a spectrophotometer. Finally, we will measure fluxes of CO2, methane and nitrous oxide using portable greenhouse gas analyzers.Solar energy opportunities. This part of the project will build on the geospatial analyses.To estimate the technical potential for solar power generation (or 'installed capacity', in MW), we will use published data on the power density (MW km-2)of floating solar power compiled by the National Renewable Energy Laboratory (NREL). Technical potential data will be transformed into actual solar energy generation (MWh per year) using NREL's PVWatts Calculator, a free application for estimating the energy production and cost of energy of grid-connected solar power systems throughout the US. In addition to creating scenarios with solar energy generation potential, we will evaluate pros and cons associated prospective locations, considering other uses that may conflict with solar energy generation (e.g., recreation and fisheries in reservoirs and resacas), as well as logistical constraints, such as proximity to the electrical grid. The analysis of water losses will allow usto develop preliminary quantifications of water conservation benefits from covering irrigation infrastructure with solar panelsin the RGV.

Progress 06/01/23 to 05/31/24

Outputs
Target Audience:This project targets four key audiences: 1) the scientific community, 2) local irrigation districts and city water utilities, 3) local and regional government, and 4) the solar power industry. We have engaged these audiences primarily through student-led presentations regional conferences (detailed in the Products session), which are expected to culminate in student theses and peer-reviewed publications by the project's completion. These presentations not only reached the scientific community but also engaged local stakeholders, as they were delivered at conferences attended by members of Rio Grande Valley community (e.g. Subtropical Agriculture and Environments conference). Beyond presentations and publications, we have established connections with local water utilities. For example, a group of senior civil engineering students mentored by the project PI, Dr Cheng, worked closely with the City of McAllen Public Utility to assess the technical potential of implementing a floating solar system on one of their water treatment facility reservoirs. Changes/Problems:One change in our approach involved the water quality sampling component. Initially, we planned to sample multiple sites. However, the team encountered challenges in obtaining authorization to sample across various irrigation systems, which are managed by over a dozen different irrigation districts in the region. To address this issue, we shifted our focus to conducting biweekly water quality sampling at two resacas (ancient distributaries of the Rio Grande currently used for multiple purposes, including irrigation). This adjustment is generating a novel dataset for an understudied system in an understudied region. Another major change in the project was the departure of the initial PD, Rafael Almeida, from UTRGV. After consulting with USDA program manager, it was decided that the project would remain at UTRGV, with Almeida continuing his involvement through a subaward to his new academic institution, Indiana University. Additionally, Almeida's master's student, who was funded through the project, has transferred to Indiana University for a PhD program. The student will continue to contribute to the project once the subaward is in place. While these changes are not expected to drastically impact the project's outcomes, they have caused some delays, which may prompt the PD team to request a no-cost extension in the future. What opportunities for training and professional development has the project provided?This project is directly funding two graduate students at UTRGV, whose work is aligned with achieving project goals. Additionally, a third graduate student as well as a undergraduate student, supported by internal UTRGV funds, is also contributing to the project. All students are actively engaging in professional development opportunities, including learning new instrument for data collection, participation in regional and national conferences. Furthermore, a group of senior-design undergraduate students (n=6) from UTRGV's civil engineering program, under the mentorship of project PD Cheng, has developed a cost-benefit analysis for the potential installation of floating solar power on a local water treatment facility reservoir. In summary, the project is providing valuable learning opportunities for both undergraduate and graduate students while generating new knowledge to advance the field. How have the results been disseminated to communities of interest?Preliminary results were presented and disseminated at local and national conferences (see Products and Other Products). Senior design project (by Civil Engineering students) was presented to City of McAllen. More results and analyzed data are expected to submit to peer-reviewed scientific journals for publication. What do you plan to do during the next reporting period to accomplish the goals?Students involved in the project will continue advancing their thesis work, actively contributing to the academic community by participating in regional and national conferences while helping the team achieve the project's four goals. These opportunities will allow them to present their findings, receive feedback, and network with professionals in their field. Additionally, the students will focus on publishing their research in peer-reviewed journals, ensuring that their contributions to knowledge in freshwater sustainability, irrigation systems, and renewable energy are disseminated widely. This exposure not only enhances their academic profiles but also positions them as emerging experts in fields critical to the economic and environmental resilience of regions like the Rio Grande Valley.

Impacts
What was accomplished under these goals? Two graduate students funded by the project, Syed Fahad Abdullah and Augusto Del Claro, have consolidated existing irrigation data in the Rio Grande Valley, which are being complemented by new data (Goal #1). Their preliminary findings were presented at regional conferences and are scheduled to be presented at the American Geophysical Union's Annual Meeting in December 2024 (see Products). Abdullah's project focuses on quantifying current water losses and water savings potential of covering irrigation systems with solar PV (Goal #2), whereas Del Claro's project focuses on assessing the solar energy generation potential for co-locating solar power with irrigation (Goal #4). These datasets will be part of their theses research. PD team also expects to publish associated data and findings in peer-reviewed publications next year. In addition, graduate student Siena Stassi (not funded directly by the project), co-mentored project co-PIs Dr Benavides and Dr Almeida, has been conducting bi-weekly samplings of water quality parameters (Goal #3) and measuring greenhouse gas fluxes in systems near the Rio Grande Delta (see Products).

Publications

• Type: Journal Articles Status: Published Year Published: 2024 Citation: Almeida RM, Chowdhury A, Rodrigo H, Li M, Schmitt R (2024). Offsetting the greenhouse footprint of hydropower with floating solar photovoltaics. Nature Sustainability https://doi.org/10.1038/s41893-024-01384-w
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Del Claro A, Dong TY, Cheng C, Benavides J, Almeida RM. Water savings and energy generation potential from covering water systems with photovoltaic panels in the semi-arid Rio Grande Valley of Texas UTRGV College of Sciences Annual Research Conference 2024 | April 2024 | Edinburg, TX Del Claro A, Dong TY, Cheng C, Benavides J, Almeida RM. Water savings and energy generation potential from covering water systems with photovoltaic panels in the semi-arid Rio Grande Valley of Texas. 78th Subtropical Agricultural & Environments Society Annual Meeting | February 2024 | South Padre Island, TX Abdullah SMF, Cheng CL, Almeida RM, Benavides J. Modeling selected water quality parameters in Arroyo Colorado basin under climate extreme for possible Managed Aquifer Recharge (MAR) using HEC-RAS. 2024. 2024 Annual Research Conference, Edinburg, TX Abdullah SMF, Cheng CL, Almeida RM, Benavides J. Modeling selected water quality parameters in Arroyo Colorado basin under climate extreme for possible Managed Aquifer Recharge (MAR) using HEC-RAS. 2024. 26th Annual Stormwater Planning & Management Conference, South Padre Island, TX Stassi S., Benavides J., Barros N., Almeida R. Greenhouse Gas Fluxes from Managed Aquatic Systems of the Rio Grande Delta. Association for the Sciences of Limnology and Oceanography 2024, Madison WI Stassi S., Benavides J., Barros N., Almeida R. Greenhouse Gas Fluxes from Managed Aquatic Systems of the Rio Grande Delta. College of Science Graduate Research Symposium. 2024, Edinburg TX Stassi S., Benavides J., Barros N., Almeida R. Greenhouse Gas Fluxes from Managed Aquatic Systems of the Rio Grande Delta Subtropical Agriculture and Environment Society. 2024, South Padre Island Preota SA, Cheng CL. Co-Benefit Potentials of Flood Mitigations and Increasing Water Supply via Groundwater Recharge in Arroyo Colorado Watershed in South Texas. 2024. College of Sciences Annual Research Conference 2024. Edinburg, TX.
• Type: Conference Papers and Presentations Status: Submitted Year Published: 2024 Citation: Abdullah, S.F., Cheng, C. L., Preota, S.A., Del Claro, A., Benavides, J. and R.M. Almeida. 2024 Suppressing evaporation loss by covering irrigation water supply systems in Texas Rio Grande Valley with solar photovoltaic panels. 2024 AGU Annual Fall Meeting, Washington D.C. Dec. 9-13, 2024. Preota, S.A., Cheng, C. L., Abdullah, S.F., Kim, J. and M. Hwangbo. 2024 Remediation of Pb and NH3 with a Soil-Aquifer-Treatment System using Fine Sand-Biochar Porous Media. 2024 AGU Annual Fall Meeting, Washington D.C. Dec. 9-13, 2024.