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Water supply and salinity at a restoration site in the Spanish Altiplano

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This page is for synthesizing strategies for developing 1) drinking water and 2) irrigation water, at a restoration camping site in the Spanish Altiplano. This site is a 5 ha demonstration site at approximately 1000m in the Arid South of Spain.

Site Description[edit]

  • There are locality and detailed site maps.
  • Here is a 16-year rainfall record describing erratic rainfall patterns.
  • Only a 5 ha site is managed by the campers.
  • Surrounding lands are managed by other farmers.
  • A water harvesting system has been installed with a series of off-contour swales feeding into a series of four ponds.
  • The ponds are located along a valley line, receiving flow from an approximately 200 ha catchment.
  • There are wetland indicator plants in the valley.
  • The soils have a high clay content.

Observed Problem Description[edit]

  • Water salinity in the ponds is increasing over time.
  • There are long gaps between rainfall (see precipitation analysis at the end of the map page.)
  • The smaller and lower ponds are more saline (4000 ppm) then the upper ponds (800ppm).

Objectives[edit]

  • Develop a potable water supply on the site
  • Develop irrigation water supply on site that won't make soil saline.

Key Assumptions/Questions/Hypotheses[edit]

  • Why is the water getting more saline over time?
    • Ground water is saline and is interacting with the ponds?
    • Verify groundwater salinity by sampling groundwater uphill of pond?
  • Why are small ponds more saline than large ponds?
    • Higher evaporation rate, but they are 5 times as salty?... that's a lot of evaporation!
  • Why do you need to have potable water stored on site?
    • The project aims to demonstrate how people can reside on degraded lands as part of restoration.

Solution Alternatives[edit]

  • Water-tight cisterns for storage of potable water.
  • Solar distillation for survival levels of potable water.
  • Let saline water flow through a polytunnel growing edible halophyte plants or fungi.
  • Reduce evaporation with shade cloth or living canopy or windbreak
  • Reduce evaporation with impermeable cover.

Related Pages[edit]