Alexa Bertinelli - University of Arizona



Alexa Bertinelli

Khushartini Kamarulzaman

UNVR 195a

04/08/04

Santa Cruz River in the White Dove of the Desert

The San Xavier Mission, the white dove of the desert, just south of Tucson in the Tohono O’odham Reservation remains a stoic reminder of the past. However, the area around it has changed considerably, especially around the adjacent Santa Cruz River. The groundwater aquifers below the river have been pumped over the years and now the riverbed suffers from a lowered water table and loss of vegetation. Fortunately, San Xavier has a general mission which is concerned with restoration and protection of the river. It is also involved in activities such as the installation of new irrigation systems, as well as the construction of flood control channels, new farm headquarters facilities and new roads.

James Riley and his class of students from the University of Arizona went for a visit to a restoration site on the Santa Cruz near the San Xavier Mission. The students met with a representative for the project, Mark Brigg, whose responsibility is to manage the riparian restoration, to be in charge of site assessment ecologist monitoring, and to keep the restoration projects successful as well. A rich riparian habitat used to exist along the Santa Cruz River, and the main objective of this restoration project is to restore the area of vegetation and then protect it. The restoration site is located just to the south and west of the bridge over the Santa Cruz River. The river makes a turn to the west as it goes under the bridge and the project is to the inside of that turn in an area that normally is not flooded (an exception being the huge floods of 1983 and 1993).

The site resembled a little valley, with deep escarpment on all sides. The Santa Cruz River used to have gentle slopes, allowing the flood waters to spread out and slow down, feeding the vegetation along the banks.. Due to the deep cutting of the channel, the river moves much quicker through the channel, thus changing the nature of the river. The channel cutting, along with the lowered water table, has caused the habitat to change considerably.

The restoration site was selected after examining the surface and subsurface conditions. The area has what is called a perched water table below it. This means that in addition to the deep main water table, which is now several hundred feet below the surface, there is a shallow water table formed by a clay layer (at 27 feet below the surface) that stops or slows downward percolation of water. This layer helps keep the water near the surface so it can be accessed by the new plants. The selection of the plants was determined by a combination of ecological possibility and the wishes of the tribal elders. The latter wanted the area to closely resemble what the river used to look like not so long ago, when it was lush and full of life. In this area, a large Mesquite Bosque is being planted in the center (bosque is a Spanish word for “woodland”). It is a highly productive habitat in terms of mammals, birds, insects and reptiles that make the use of shade and food resources. Cottonwood and willow poles were planted in the area as well because they are easy to grow and grow rapidly.

In addition to reestablishing the habitat, the site will also serve as a recreational facility.

The Mission itself serves as grounds for an American Indian arts and crafts market with picnic areas and facilities that contribute to the neighborhood. The site will become a beautiful park-like area for the neighborhood. There are two ponds in the area fed by the Central Arizona Project (CAP) water that have been created to resemble old water holes and are intended to have a wide range of plant types. It thus will become an oasis in the dry desert for residents to bring their families to enjoy nature.

Moreover, this project received its monetary support from the Arizona Water Protection Fund (AWPF). AWPF is a source of money for the development and implementation of measures to protect water in order to maintain its sufficient quality and quantity. They also enhance and restore rivers and their associated riparian habitat.

The human use of the Santa Cruz River and its aquifer from the earliest human presence in the valley until today has changed considerably. In creating this site, the social, cultural, and political history of the Santa Cruz Valley have been examined while keeping in mind future needs of the people. It is important because water will always be the focus for human activity in the desert and we desperately need a more complete understanding of its place in our lives.

Work Cited

Mark Briggs, Restoration Ecologist at Southern Arizona Water Rights Settlement Act (SAWRSA) Development and Water Management Area.

The History of Santa Cruz Valley,

San Xavier del Bac Mission History,

Danielle Crounse, San Xavier del Bac Mission, 1997-2000,

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