Underwood Family Sonoran Landscape Laboratory

Challenge

Though the site was part of a parking lot, the University of Arizona College of Architecture and Landscape Architecture (CALA) faculty wanted it to become an interpretive learning experience with a range of materials that would be a fun oasis and attraction for existing and future students and professors of the CALA program.

Solution

The design was inspired by the fact that the parking lot runoff all seemed to drain to what would be the new building entry space. The idea of creating a new entry and garden/outdoor classroom that would be a cleansing biosponge garden for adjacent runoff and discarded water from the new building was received positively by the faculty and university. 

• Five distinct Sonoran Desert biomes are represented within the project limits: Arizona Wetland, Canyon, Desert Riparian, Mesquite Bosque, and Upland Sonoran.
• Stormwater runoff is reduced by 2 desert arroyo “micro-basins” and the lower patio, which have the capacity to retain 5,500 gallons total.
• An accessible, sunken court serves as outdoor classroom and gathering space and retains runoff during desert storm events. The court is composed of permeable stabilized decomposed granite and framed by cast-in-place concrete seat walls of varying heights.
• The 4,000-gallon desert wetland pond is a potential candidate for listing as a “Safe Harbor” urban site by the U.S. Fish and Wildlife Service.
• The landscape is totally integrated with building mechanical systems. Roof runoff, HVAC condensate, and drinking fountain greywater are harvested and stored in a vertical 11,600-gallon cistern for use in irrigation.
• Native butterfly vine (Mascagnia macroptera) vines climb 50 ft up a scrim on the building’s southern exposure, reducing solar heat gain and blurring the lines between architecture and landscape.
• A bosque of native mesquite (Prosopis velutina) creates dappled shade in the entry plaza.
• The high efficiency drip irrigation system is controlled by monitoring evapotranspiration rates.
• The project creates significant terrestrial and aquatic habitat, and facilitated the introduction of 2 threatened and endangered fish. Opportunistic repopulation and active predation activities have been observed.
• The desert riparian channels were lined with reused brick and concrete from the partial demolition of the building.
• All materials and labor were sourced from within Arizona, with the exception of some irrigation components and the pond liner.
• All materials and labor were donated through extensive cooperative efforts among the landscape architect, Campus Facilities, and the Arizona green industry.

All materials and labor for planting, irrigation, and lighting were donated, with a total estimated value of $650,000. The construction cost of the hardscape was about $400,000. This project shows that a high performance design that harvests water, mitigates urban heat island, reduces urban flooding, and provides an can be achieved at a relatively low cost. 

• Appropriate and judicious plant selection reduces installation and maintenance cost; the site’s maintenance costs have been quite low. 
• There was an issue with the connection between the ET irrigation controller and the booster pump, which were resolved by the installation of a larger industrial cistern water filter. 
• Goldfish had to be removed from the pond before introduction of native species of fish. 
• Learning opportunities increase when places for social interaction are integrated with outdoor curriculum study zones.

Project Team

Landscape Architect: Ten Eyck Landscape Architects, Inc.
Architect: Jones Studio
Civil Engineer: Evans Kuhn
Mechanical Engineer: Kunka Engineering
Irrigation Design: Carl Kominsky
Wetland Consultant: Wass Gerke and Associates
General Contractor: Lloyd Construction Company, Inc.
Landscape Contractor: AAA Landscape
Donors: The Robert and Richard Underwood Family, AAA Landscape, Mountain States Nursery, Arid Zone Trees, Western Tree Company, Rain Bird Irrigation, Kalamazoo Materials, FX Luminaire

Role of the Landscape Architect

The landscape architect managed the project during all phases from design through construction, including the solicitation of donated labor and materials.