Limans are structures with small dams which catch runoff from a wadi to hold about 400-600mm of water, which suffices for the growth of drought-hardy tree species. Limans can be built wherever tributary wadis [...] widen or come onto a large plain with potential arable land [...]. A check-dam [...] is built to retain runoff waters [...]. A spillway regulates the level of the water [...] to prevent the destruction of the check-dam.. The embankment height should be 3–4 times the designed water depth, and the outlet should be to the side of the main flow to prevent direct through flow. Also, grazers should be excluded from the site to prevent soil compaction which would in turn decrease water infiltration.