II. Surface Runoff Water Harvesting
This group of techniques depends on the harvesting of surface runoff water from a small catchment area ranging from a few square meters to around 1000 square meters.
Water accumulates in artificial depressions from direct rainfall and surface runoff to form water pools and ponds. The amount of water and its persistence in the pond depends on the amount and seasonality of rainfall as well as the spacing of rain storms. It also depends on the compaction, pavement or smoothing of the catchment area, which can be artificially enhanced. It also depends on reducing infiltration by sealing the bottom of the pond and lining the pond with stones and plaster. They range in capacity from 1000 to 500,000 cu.m.
In Syria, a Birka is a stone built reservoir.
Crescent shaped earth bunds, usually constructed in staggered rows.
Bunds arranged downslope in straight lines to slow surface runoff and increase infiltration.
Crescent shaped earth ridges constructed down-slope from trees to increase water harvesting and infiltration in the ground.
Circular ridges from earth constructed to enhance water retention and infiltration.
The construction of a wall around a tree in order to retain moisture and occasional precipitation
Reshaping the slope by a series of more or less flat steps.
Earthen low ridges arranged to create artificial basins.
Contour ridges
Linear ridges constructed along the contour lines at intervals of between 5 and 20 meters.
Contour bench terraces
Often on very steep slopes, the terraces are supported by stone walls. Common in Yemen for growing coffee and qat as well as trees and field crops.
Stone Mounds
Small stone mounds were used by the Nabateans to enhance surface water runoff by as much as 25%. They are called by the Bedouins Tuleilat el-‘Anab (vineyard hillocks) and might have been used for supporting the cultivation of vineyards (Issar 1990, 181). The system is perhaps analogous to the more substantial “Kroum” of the Egyptian coast.
Small (0.3-2 m in diameter), deep pits (5-15 m). A dyke may be constructed downslope from the pit.
Artificial mounds of earth constructed to allow rainwater to flow into farming area and subterranean cisterns. Used on the coastal area of Egypt in Roman times to irrigate vine and olive orchards. (Photos F. Hassan, Maryut, Egypt)
Used on gentle slopes, one bare strip is used as a catchment while the strip downslope from it is used for growing crops,
mostly field crops.
Negarim (small runoff basins)
Small (5-10 m in width and 10-25 m in length) runoff basins, rectangular, elongated or diamond-shaped surrounded by low earth bunds. Suitable for tree crops.
Hillside conduit system
Excavation of water runnels to harvest water and direct it to where it is needed.
Hillside aqueduct
A canal to transfer water running along a hillside. A wall may be built to form the outer wall of the aqueduct.
Water flowing downhill is directed to flat-lying fields by small conduits before it joins the wadi. A spillway may be used to drain excess water for use downstream.
Large earthen or stone built reservoir dug into the ground downslope from a wadi to collect water.
Tanks for water storage, often circular with plastered floors for domestic use (Yemen).
A settling tank is situated so that solid particles in the water are allowed to settle before water enters the pond.
Small subsurface water containers with a capacity ranging from 10 to 500 cu. m. They are often rock-cut. Varieties include pit cisterns, jar cisterns, or built stone cisterns. They receive water from rainfall, water drip in caves, groundwater, or runoff. A settling area may be used to remove solid particles in water.
Matfia (Morocco)
Underground cistern for rainwater harvesting
A settling basin is constructed to prevent solid particles from entering the cistern.
Roofed tanks or cisterns below ground with roof above ground.
Abar Romani (Syria)
Cisterns excavated in bedrock, Syria.
A cistern covered with a dome-like structure, Iran.
Constructed on the coast of Egypt during WWII by the British troops to store water (Photo F. Hassan, Dab’a, Egypt)
