MAR site suitability

Identification of areas where water can be infiltrated, stored in an aquifer and recovered for later use.

Managed aquifer recharge (MAR) stores water in aquifers for later recovery or environmental benefit. The MAR application maps where a defined type of scheme is feasible and narrows a region down to the areas that justify field investigation.

OutputSuitability map per category and a combined feasibility map

DecisionPrioritisation of areas for field investigation of potential MAR schemes

ScaleWatershed to continent

Built forA defined MAR typology

Default categories

A MAR scheme needs an aquifer that can receive and store water, a source of water and a demand for the recovered water. The suggested criteria follow the AGREEMAR feasibility matrix and fall into four categories, each with its own suitability map. These default categories can be renamed or removed by the user, and new categories can be added.

Intrinsic site suitability

Capacity of the surface, the unsaturated zone and the aquifer to infiltrate, store and transmit water.

Availability of water

Quantity and quality of the source water, and its distance from the recharge site.

Water demand

Domestic, agricultural, industrial and environmental needs met by the recovered water or by recharge itself.

Non-physical considerations

Governance, social acceptance, costs and operational safety of a scheme.

The criteria library is maintained continuously. In each project, criteria can be added, removed or renamed.

MAR typology

Criteria, scoring directions and weights depend on the type of scheme. Each MAR project records the typology its map is built for; the selection appears in the report and in the metadata of exported maps.

  • Main objective
  • Recharge technique
  • Source water
  • Use of recovered water
  • Target aquifer

Constraints

Constraints exclude areas from the analysis regardless of their score, such as protection zones, built-up areas or contaminated land. The suggested constraints follow a modified PESTLE framework: Planning, Economic, Social, Technical, Legal, Environmental.

From criteria to feasibility

  1. CriteriaStandardised to a common scale in the direction set by the typology
  2. Category mapsWeights within each category give its suitability map
  3. Feasibility mapWeights between the categories combine the category maps
  4. Candidate areasContiguous areas of very high feasibility in which no criterion falls below a minimum value

The typology influences how the criteria are scored by the user: spreading methods require a thick unsaturated zone, well injection does not; proximity to the coast lowers the score of a storage scheme and raises that of a seawater-intrusion barrier. Weights come from the analytic hierarchy process, ranking, rating, the multi-influencing factor method or an anonymous stakeholder survey.

Results

Map of MAR feasibility in the Chiba watershed for the wet season
Wet-season MAR feasibility, Chiba watershed, Tunisia. Chekirbane et al. (2025), CC BY-NC-ND 4.0; adapted by the authors.

The result classes rank the locations within the study area; they do not represent an absolute recharge capacity.

Sensitivity analysis shows which areas of high feasibility persist when the weights change. Validation against existing MAR sites will follow in a later version.

Typical questions

  • Which parts of a region combine favourable aquifer conditions, available source water and water demand?
  • Where can infiltration basins fed by treated wastewater be implemented?
  • How does the feasible area differ between the dry and the wet season, or between stakeholder groups?
  • Which candidate areas should be investigated first?

Case stories

Read more

References

Start a MAR project

Select “MAR site suitability” when creating a project. The suggested criteria and constraints appear in steps 2 and 4.