Kino Environmental Restoration Project (KERP)


Ed Pastor Kino Environmental Restoration Project

The Ed Pastor Kino Environmental Restoration Project (KERP) is an excellent example of a sustainable living community. This project demonstrates what can be achieved when people join forces and share resources to achieve a common goal. Although it’s located on the Kino Sports Complex property, this basin is maintained primarily by the Pima County Regional Flood Control District who ensures KERP meets the state and federal guidelines set forth for an environmental habitat.


Transformed and Thriving

In the mid 1990s, the U.S. Army Corps of Engineers and the Pima County Flood Control District entered into a cooperative agreement to reconstruct and expand the original 50-acre Ajo Detention Basin, now known as the Ed Pastor Kino Environmental Restoration Project (KERP). This project was the result of the agencies’ desire to redevelop an existing unlined storm water detention basin – Tucson (Ajo) Detention Basin – into a detention basin that was more environmentally sensitive and aesthetically pleasing to the community. The multifaceted KERP facility was designed to meet three primary purposes – create native ecosystems, harvest urban storm water and control flooding.

The final footprint of the new KERP covers 141 acres that contains 28 acres of riparian and open water including a 5.6 acre, fifty-foot deep pond; 21 acres of grassland, mesquite bosque, marsh and upland vegetation that rises to an elevation of 2,520 feet; and another 92 acres that includes flood control structures, a basin earthen berm, and a recreational path that surrounds the basin.


This terrain has five different environments

Arizona Uplands

Tucson is located in the Arizona Upland Subdivision of the Sonoran Desert where Palo Verde trees, saguaro, cholla and prickly pear cacti are common. Desert birds nest and forage within the protection of these thorny plants, and other animals like javelina, jackrabbits and desert tortoises feed on the cactus pads and fruit. Arizona Upland birds to look for are the Red-tailed Hawk, Gambel’s Quail, Curve-billed Thrasher, Cactus Wren, and the Greater Roadrunner.

Open Water

In ponds and lakes, open water is the habitat found beyond the shallow water and plants of the shore. Diving ducks feed in open water, seeking out water insects, snails, and aquatic plants. Open water birds to look for are Mallard, Northen Shoveler, RingneckedDuck, and the Belted Kingfisher.

Riparian Communities

A riparian community is made up of the plants and animals living along streams and rivers. In the desert these areas are important to many wildlife species. Riparian trees like cottonwoods and desert willow depend on the water available in the river bottoms and banks. Eighty percent of Arizona’s wildlife species utilize or depend upon the resources of riparian areas. Riparian birds to look for are the Wilson’s Warbler, Black Phoebe, Song Sparrow, and the White-winged Dove.


A wetland is the place where land meets water, at the edge of a pond, lake or river. Wildlife thrives in wetland habitat because of the abundant water and the cover provided by wetland plants like reeds and cattails. Migratory waterbirds rely on wetlands as stopover points during their long journeys in the spring and fall. Wetland birds to look for are the American Coot, Red-winged Blackbird, Great Blue Heron, and the Black-necked Stilt.

Mesquite Bosque

A dense stand or “forest” of Mesquite trees is called a Bosque. Mesquite trees are especially adapted to our dry climate, sending tap roots down as deep as 150 feet to reach water during times of drought. Mesquite bosques provide shade and shelter for wildlife and other plants. Mesquite seeds are rich in protein and are an important food source for many animals. Mesquite Bosque birds to look for are the Gila Woodpecker, Ladder-backed Woodpecker, Vermilion Flycatcher, and the White-crowned Sparrow.


Flood Storage and Water Harvesting

An extensive pumping and valve system circulates and mixes reclaimed and storm water within the basin. When the water from the watershed covering a 17.9-square-mile area around Davis-Monthan Air Force Base enters KERP, its first destination is a debris basin equipped with a trash rack to retain sediment and trap floating objects. Water then passes into the lined storage ponds that retain the runoff by preventing seepage into the aquifer. Two small weirs and a weir gate regulate the flow of water into the deep pond.

Water is circulated along the three stream courses that drain into the ponds, and cooler water is also pumped from the bottom of the 50-foot pond to the top of the stream courses to improve water quality and aid with vector control.

Water levels fluctuate depending on the availability of storm water. During periods of extended dryness, reclaimed water is purchased from Tucson Water to maintain pond elevations and protect marsh habitats, the Mesquite Bosque and grasslands. Reclaimed water is treated wastewater (effluent) from the metropolitan treatment facilities that is distributed by the City of Tucson’s reclaimed water system. A 16 inch reclaimed water pipeline feeds water into the pond. In addition, the open water areas and marsh can be fed by three additional pipelines at KERP.


Harvesting Storm Water

Harvested storm water is a low cost alternative to purchasing and using ground water. Here are some of the areas that are irrigated with KERP water: The basin’s vegetation; Kino Sports Complex ballfields; surrounding athletic fields; median landscaping and easements; along Ajo Way and Country Club Road; University of Arizona landscaping; Herbert Abrams Public Health Center landscaping; landscaping at the Public Defense, Juvenile Court and Adult Probation buildings.


Community Enrichment

A 2.2 mile paved trail for walking, jogging, bicycling, and wildlife viewing including bird watching is open to the public. The trail links to The Chuck Huckelberry Loop pedestrian and bicycle path being developed to connect the Rillito, Santa Cruz and Pantano river parks with the Harrison Road and Julian Wash greenways.


Bird Watching Protocols

Under normal circumstances, bird watchers are welcome at KERP. Please obey all signs, safety protocols and staff directives when on site. Recorded bird calls are not permitted. In order to protect habitat value, access to any fenced area is prohibited except by prior agreement. Maintenance trails within the basin are not open to public access.

Audubon birding field trips sometimes visit KERP. For more information about birds and local birding field trips, visit the Tucson Audubon Society website at or contact the Society at 520-629-0510 or



Chief of Engineers Award of Excellence – 2006

In 2006 the Army Corps of Engineers recognized KERP with the Chief of Engineers Award of Excellence. This Environmental Category award cited the Ed Pastor Kino Environmental Restoration Project as an exceptional project. Judges summarized the project saying, “This is truly an exceptional project. It takes an existing mud flat in an arid area and creates aesthetic landscapes, recreation features, flood control, and is a prototype for water harvesting. It is technically sophisticated while appearing natural. It (also) has proved sustainable over the recent drought years.”


Learn More About KERP

For more information about KERP, including brochures, reports and news articles, visit the KERP site on Flood Control’s webpage.

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Map of the Kino Environmental Restoration Project

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