Managed Aquifer Storage and Recovery in Coastal Louisiana

Problem

Despite relatively abundant rainfall and surface water, groundwater is being overused across the Southeastern United States. Coastal Louisiana is no exception. 

Consequences

Overuse of coastal aquifers leads to subsidence and salt water intrusion, accelerates coastal land loss, and devastates coastal communities through the loss of available freshwater for drinking and economic activities.

Possible Solution

During high-flows, clean surface water is pumped into the aquifer for storage and later use during droughts and peak demands.
This activity combats subsidence and provides a freshwater buffer to reduce salt water intrusion.

Research Objective:

Investigate feasibility of implementing a sustainable water management  solution using engineered wetland systems and water treatment centers in conjunction with Aquifer Storage and Recovery (ASR).

Approach:

I. Surface water hydrology
II. Groundwater hydrology
III. Social and economic expectations
IV. Outreach and Education
Picture
Boundary of the Chicot Aquifer in southwest Louisiana, showing the main watersheds and contributing tributaries
Surface water hydrology
Analysis of Water Surplus/Deficit with and without ASR:
  1. Disaggregation of surface runoff data from NHDPLUS and the National Water Model at the HUC12 watershed scale
  2. Analysis of water surplus/deficit for ASR site selection suitability
  3. Analysis of time variability for capture using monthly streamflow and water demands in an irrigation-dominated catchment
  4. After the addition of ASR, examination of potential benefits for capturing water during wet years and alleviating water stresses during droughts.
Groundwater hydrology
Groundwater Model with and without ASR:
  1. Development of a localized groundwater model at a 1 km^2 resolution using MODFLOW
  2. Model simulation over 11 years to extract aquifer characteristics for ASR site selection suitability
  3. Optimization of the ASR management model to evaluate potential ASR operation efficiency
Above: MODFLOW Model of Chicot Aquifer at 1 km^2 grid
Left: Transmissivity of aquifer aggregated at HUC12 scale for site selection suitability
social and economic expectations

Systematic introduction and coordination with community:

1. Coordinate interviews with people currently using ASR systems to gather more information
​2. Connect with local stakeholders to determine potential support and analyze the technical and economical implementation of ASR 
​3. Research into economic opportunities to identify revenue options for farmers to offset costs of ASR units
ABOVE:  Meeting with local stakeholders and policy makers to discuss ASR systems
LEFT: An example of a developed pilot-site rendering to engage policy makers and stakeholders 
outreach and education

Engaging the community to create a more sustainable water-management plan: 

​1. Discuss wetland filtering and storage and ASR topics among stakeholders
2. Recruit experts (researchers, consultants, water managers) to speak publicly about water storage alternatives
3. Provide resources (fact sheets, graphics, web resources, and visualizations) to the public, utilities, municipalities, and other water officials
4. Collaborate with the Office of Conservation, Parish boards and commissions, LA Water Resources Commission, and the Louisiana State Law Institute for further outreach efforts
ABOVE: Design scenario of an integrated solution to ecotourism in combination with engineering landscapes for ASR systems