Environmental Benefits
Tucson is one of the largest cities in the U.S. that obtains its water supply from ground water. Current demand has resulted in a state wide 2.5 million acre foot groundwater overdraft; surface water cannot replenish underground aquifers as quickly as we pump water out of them. In order to address Arizona’s water needs and the depletion of groundwater sources, the Central Arizona Project (CAP) was constructed to move water from the Colorado River to areas in need of water, including Pima County. CAP cost a total of $4 billion dollars and consists of several pumping plants, and miles of tunnels, aqueducts and pipelines. Not only does such a large-scale construction project disrupt and destroy wildlife habitat, it also negatively impacts the areas downstream of Lake Havasu by removing water that previously sustained those areas. As a result wildlife and human populations are stressed, leading to environmental, economic, social, and agricultural hardships.
Setting up a rainwater collection system for your home or business is a vital step towards more sustainable water use in Tucson. Rainwater collection reduces your dependency on groundwater as well as the need for expensive, destructive water projects. By irrigating your landscape with collected rainwater you significantly reduce your use of drinking water and all of the chemicals and treatment infrastructure associated with municipal drinking water.
Rainwater is a clean, salt-free source of water for plants. Rainwater does not contain chlorine and by-products that are used in the water treatment process. Nor does it contain the naturally occurring hard minerals that are found in groundwater. Rainwater is also free of the pesticides and chemicals that can contaminate groundwater. Irrigating with rainwater can further reduce salt accumulation in soil, which can be harmful to root growth. Irrigating with collected rainwater promotes greater root growth and water uptake by percolating into the soil and pushing salts down and away from root areas. The result is an increased drought tolerance of plants.
Improved plant growth allows you to create a lush desert landscape around your home, which in turn creates shading and natural cooling. Rainwater irrigation also enables you to grow food in a sustainable manner, as well as reducing soil erosion and loss of topsoil. Using collected rainwater connects you to the natural water cycle and gives you an even greater appreciation of this precious resource. Collecting and storing your own supply of rainwater enables you to better monitor the amount of water you use which leads to a deeper conservation ethic.
Your choice of tank style also affects the environment. The culvert style tanks are made with at least 31% recycled materials which exceeds the LEED certification requirements which are at least 25% recycled material. Fiberglass tanks have a lifetime warranty and therefore reduce landfill waste.
By conserving, harvesting and reusing water, we can each contribute to a more sustainable Tucson.
For a comprehensive guide to rainwater catchment and passive water harvesting, see Rainwater Harvesting for Drylands.