Tucson Nature Conservancy
Client: Tucson Nature Conservancy
The Tucson Nature Conservancy has a long history of sustainable practices that have been used to demonstrate sustainable landscaping, vegetated swales, rainwater harvesting and more. The Conservancy wanted to update their drip irrigation system and expand the storage and capabilities of their rainwater harvesting system. They also saw the opportunity to provide a community service with a demonstration project on rainwater harvesting practices. Wahaso was asked to help with the system design and implementation.
System Type: Rooftop Rainwater to Irrigate Landscaping
Commissioning Date: February, 2012
Challenge: The existing above-grade cistern was not large enough to store the rainwater needed for irrigation, and there was not enough room on the property for a larger tank. Also, they wished to automate the harvesting system and ensure that the water was safe from pathogens that might create a health hazard.
Solution: Wahaso recommended the Atlantis system for below-grade storage with a 30,000 gallon system constructed on-site out of recycle polypropylene plates. The long dry season required a system that could store the water for months without the risk of it going anaerobic with the associated issues of bad odors and color. A dual filtration step with U.V. sanitation filters the water to 5 microns and essentially sterilizes the water exiting to the irrigation system to minimize any risk to public health. Rainwater is collected from both the building rooftop and off the solar car shade surfaces.
Results: The Atlantis system's passive water quality management uses natural thermal and capillary action to keep water in the cistern moving with a circulation pump, and a natural bio-film on the plates and in the sand layer actually improves the quality of the water in storage. The system is expected to save 60-70,000 gallons per year while providing a demonstration project to the visiting public on rainwater harvesting storage and treatment methods.