The Water Retention Landscape of Tamera Peace Research Center in Southern Portugal is a model for natural decentralized water management, restoration of damaged ecosystems and disaster prevention. It is a basis for reforestation, agriculture and aquaculture, especially in regions threatened by desertification, and is an integral part of a comprehensive model for sustainability in water, food, energy and social structures. (See also http://challenge.bfi.org/2012Finalist_Tamera)
The global crises of hunger, water scarcity and rapid urbanization worsen as deforestation and inappropriate agriculture degrade vast areas of land and interrupt hydrological cycles. Soil that can no longer absorb the rain is eroded, resulting in desertification, falling groundwater levels, and disastrous floods. A new approach to water management is urgently needed.
The model consists of interconnected rainwater retention spaces (or “lakes”) designed (by Sepp Holzer) harmoniously into the landscape. The lakes are created by building earth dams, behind which rainwater is stored. The lakes are not sealed, so the water can seep into and soak the surrounding earth-body. They are built with deep and shallow zones and meandering shorelines, so the water moves constantly ensuring its vitality, oxygenation and self-purification. Terraces are built around the lakes for organic cultivation of fruit trees, vegetables and other crops, and mixed aquaculture can be established in the lakes.
The goal is to retain all rainwater on the land, replenish the groundwater, encourage springs to reappear, and reduce soil erosion to near zero, while supplying a community of 300 people with healthy organic produce. Five lakes have already been created across Tamera's 150 hectare (370 acre) site, and ten more are planned. The results visible so far are that natural vegetation has recovered, much wildlife has returned, a spring has reappeared, and crops can be grown on the lakeside terraces throughout the year requiring less and less artificial irrigation.