Ditches and furrows

Ditches, furrows or drains are point or linear structures that allow for the recharge water to infiltrate to the aquifer underneath. They are usually shallow, flat-bottomed and closely spaced structures that are excavated. This spreading methods is used mainly on irregular terrains to collect and allocate the water or in areas where an impermeable layer is present in the upper soil profile. These methods also include reverse drainage, which means that the recharge water flows into a network of perforated drainage pipes from which it infiltrates into the soil.

Typical system capacity scale	Household – Town (102m3/year – 106m3/year).
Geology	Unconfined aquifers composed of permeable sedimentary rocks and fractured crystalline rocks.
Topography	Preferably flat or gentle sloped terrain. Slope characteristics can be interrupted to enhance infiltration by using these technologies.
Soils	Permeable soils able to guaranty water quality standards to the targeted aquifer. Impermeable layers in the upper soil profile may be overcome by the use of these techniques.
Water source	River water, stormwater, treated water, lake water.
Pre-treatment	Depending on water source quality.
MAR main objective	Agriculture, domestic, and industrial.
Relative cost	Low – Medium.

Advantages

• Structures can be installed on irregular terrain.
• In case of reverse drainage, structures are indipendant of land use and as such
  good solutions for expensive land (combined use).

Limitations

• Can be applied only to unconfined aquifers.
• Require large permeable areas.
• Potential for surface water-related diseases and vectors breading.
• Potential water pollution.

Case studies

• Los arenales, Spain
• Cottesloe, Australia

References