Similar to a sieve, the willows allow water to flow through but trap the sediment back. Within a year, these structures can trap up to 10cm of sediment. Over time, this increases as the willows become more established and more sediment can be kept back. After 20 to 30 years, the vegetation will have complete cover and sediment erosion is almost completely stopped.
"Deforestation also drives climate change. Forest soils are moist, but without protection from sun-blocking tree cover they quickly dry out. Trees also help perpetuate the water cycle by returning water vapor back into the atmosphere. Removing trees deprives the forest of portions of its canopy, which blocks the sun’s rays during the day and holds in heat at night. This disruption leads to more extreme temperatures swings."
Small-scale hugelkultur in raised beds - the garden goes all summer with just one watering, sustain plants plants from less arid zones, turn soil into an active soil web that feeds plants... http://www.permaculture.co.uk/readers-solutions/small-scale-hugelkultur-raised-beds
The best way for Self-Watering Use 2-litre bottles with Aqua Cones to keep your plants and flowers watered. Aqua Cones work with any soil type because they were designed with punch-out holes near the top for sandy soil, near the middle for loam, and near the bottom for heavy soils. The Aqua Cones collects rain and stores it so that it can provide continuing water to your thirsty plants.
Rain Harvesting A study in the Journal of Soil and Water Conservation found that regardless of the type of soil (sandy loam, clay, etc.), “as organic matter increased from 1 to 3%, the available water capacity approximately doubled. When organic matter content increased to 4%, it then accounted for more than 60% of total.” That means we can now be rain harvesting 2 or 3 inches of rain from the roof, 20-30 times more than your rainwater barrel. This is what organic gardening is all about.