KERP Pima County’s Urban Oasis INTRODUCTION

31 e are standing on the edge of a vast basin Great Blue Heron , a Cooper’s Hawk and two swallows. W that’s nearly invisible from the surrounding streets. A 2.2-mile paved path for pedestri- This environmental restoration facility is the Ed Pastor ans and bicyclists hugs the perimeter and is often used Kino Environmental Restoration Project, or KERP for by office workers from nearby government buildings short. It is named for the Arizona congressman who as a place for lunch hour exercise. was instrumental in shepherding the project through Congress. It is a tranquil oasis A member of the Tucson where the practical and the Audubon Society looks into this aesthetic are perfectly blended. giant basin near Kino Parkway and Ajo Way and remarks on KERP is the end result of a the ponds and lush vegetation. multi-purpose environmental Willow, ash, cottonwood and restoration and stormwa- mesquite trees were planted in ter harvesting project. The what was once little more than a ponds are part of a carefully barren mud flat. designed flood control proj- ect that collects and captures The nearby office buildings rainwater from a 17-square belie the surrounding natural mile watershed that includes environment. It takes some ef- Davis-Monthan Air Force Base. fort to remember we are in the The harvested stormwater middle of the Sonoran Desert, is used to sustain the lush where 12 inches of rain in a wildlife habitat within KERP. 12-month period is considered a Extra stormwater irrigates Pima wet year. The Audubon member County’s Kino Sports Complex is looking through the trees at and surrounding landscaping, a Great Egret standing motion- providing a significant cost sav- less on the bank of the pond. ings to taxpayers. A moment later a flash of red darts across his field of vision, The lush habitat attracts a wide and an Anna’s Hummingbird variety of wildlife and wildlife Due to the high diversity of birds at KERP, it has become a popular settles lightly on a thin mesquite birding location watchers. More importantly, branch. KERP also protects down- stream homes and businesses. These areas would be In less than an hour of wandering the periphery of this devastated by flooding if stormwater were to follow its manmade flood control and environmental restora- natural path from the Eastside of Tucson to the Santa tion project, the birder points out two Night Herons, Cruz River. a Neotropic Cormorant, a Yellow-rumped Warbler, a 2 WATER IN THE DESERT f you stand today on the banks of the I Santa Cruz River near downtown Tucson or the Rillito Creek at Craycroft Road, you would be forgiven if you didn’t recognize that these now dry riverbeds used to provide year- round water for the lush forests and wildlife that once thrived there.

Some 15,000 years ago, the physical environment of the region was markedly different than it is to- day. With the wetter and cooler climate during the last Ice Age, large mammals that have long been extinct – the Pleistocene bison, mammoth and The Santa Cruz River at the base of “A” Mountain near downtown Tucson camels, for example – could be found grazing in in 1904. grasslands and drinking from rivers and streams.

Evidence of this history was found at the KERP site in 1990, when a County employee inspecting erosion cuts found a Pleistocene mammoth tusk buried in a prehistoric stream channel along the edge of the earthen basin.

The reasons for the transition from lush aquatic ar- eas to the dry arroyos we see today are numerous, but the rapid increase in the human population beginning in the 1880s and the subsequent urban expansion and groundwater pumping are the main culprits for the more recent drying. Picture of the old arroyo just downstream from present-day KERP, 1961. By the year of Arizona’s statehood (1912), the Santa Cruz River near downtown was no longer flowing Summer rains come fast and hard; and desert year-round. soils are incapable of absorbing more than a small percentage of the rainfall. Rain that is not absorbed Nonetheless, intense rains – especially summer into the soil very quickly begins to flow laterally rains – turn the Santa Cruz River and other regional across the ground surface, gathering speed and waterways and washes into raging rivers that can force as it flows downhill. Urban development – overflow their banks and cause flooding. pavement in particular – aggravates the situation.

4 Less than 100 years ago, the area south deaths caused by the storm: “The Thun- of downtown Tucson was a broad derstorms with heavy rain overflowed the mesquite-lined wash surrounded by banks of an ordinarily dry wash and tore creosote desert that stretched largely a 15-foot gap in the bridge on Benson unbroken to the south, east and west of Highway. Four automobiles plunged into the city. the raging torrents where ten people were drowned while four others struggled out of As Davis-Monthan Air Force Base grew the floodwaters” and the city expanded to the east, rooftops and pavement covered larger expanses of Following this event, flood control became a priority the desert. Paved streets and runways offered less and in 1948 the area’s first major flood control proj- resistance to the rainwater that fell on the water- ect, the Tucson Diversion Channel, was authorized shed; and stormwater began flowing downhill more by the U.S. Congress. The long concrete and earthen rapidly. channel collects rainwater beginning near the northwest edge of the Air Force Base at Alvernon A storm on August 9, 1945 was ranked by the Na- Way and Golf Links Road. It crosses Tucson’s south tional Weather Service (NWS) as one of the top ten side, dumping floodwaters into the Santa Cruz River weather/climate events to impact Tucson in the last southwest of the Interstate 10/Interstate century. The NWS described the destruction and 19 interchange. 5 5 n 1999, Congress authorized construction bosque (bosque is a Spanish term meaning forest). I of the Tucson (Ajo) Detention Basin Environ- This riparian, or river-supported, area is surrounded by mental Restoration Project. The project’s nearly 100 acres of upland vegetation communities. purpose was threefold: 1) to preserve flood control function, 2) to harvest stormwater for irrigation, and 3) Several Pima County departments play a role in KERP to establish natural and riparian wildlife habitat. operations. Basin managers work closely with state and federal agencies to ensure KERP meets the state Construction of KERP began in 2000 and was complet- and federal guidelines set forth for water quality and ed in 2001 at a total cost of approximately $11 million. stormwater detention. The project was funded by the U.S. Army Corps of Engi- neers and Pima County. Local contributions toward the The District performs routine monitoring for mosqui- project totaled $6 toes and applies a million. bacterial larvicide Bti (Bacillus Thuringi- The final footprint ensis Israelensis) as of KERP covers 121 needed to protect acres and includes public safety. Re- constructed stream moval of non-native courses, five invasive plant and vegetation-lined animal species ponds, restored (i.e.: buffelgrass, native vegetation bullfrogs) helps to communities and conserve urban na- a recreational path tive species diversity. that surrounds the Pima County can basin. Aerial photograph of KERP looking south. purchase reclaimed water from the City of Tucson to supplement irriga- The project included installation of approximately tion needs of wetland vegetation during extended 850,000 square feet of rubberized liner under the drought. ponds and constructed stream courses. The project also includes a 6-acre, 50-foot-deep, cement-lined KERP won the 2006 U.S. Army Corps of Engineers Chief water harvesting basin. This basin collects and supplies of Engineers Award of Excellence for Environmen- the stormwater used for irrigation. tal projects. According to the Corps, “This is truly an exceptional project. It takes an existing mud flat in an arid The streams are fed by an elaborate stormwater area and creates aesthetic landscapes, recreation features, recirculation system, and these streams support over flood control, and is a prototype for water harvesting. It is 30 acres of open water ponds, emergent wetlands, technically sophisticated while appearing natural. It has ephemeral cienegas, stream courses and mesquite proved sustainable over the recent drought years.” 6 THE BENEFITS

7 he goal of the KERP was to establish an Water Harvesting Benefits T ecosystem in a flood control basin. How- Water harvesting is the collection of rain and sur- ever, the project also provides recreation- face water runoff. A sophisticated system of irriga- al and economic benefits. tion channels dating back to 1200 BCE was discov- ered on the site of Pima County’s Tres Rios Water Flood Control Benefits Reclamation Facility. The discovery of this site, with On September 15, 2011, 2.64 inches of at least eight canals and a series of rain were recorded at Davis-Monthan HARVESTED STORMWATER agricultural fields, is evidence that Air Force Base. More than 16,000 gal- ancient people in Southern Arizona lons per second of stormwater flowed Year Gallons manipulated water flow for their from the Tucson Diversion Channel 2002 39,099,480 benefit. into KERP. Because KERP is able to 2003 28,349,074 temporarily detain over 400 million 2004 10,003,639 KERP differs from most other water gallons (1,230 acre-feet) of stormwater, harvesting projects by capturing 2005 21,147,758 the outflow westward into the Tucson runoff from a stream channel, rather Diversion Channel was reduced by 2006 0* than directly from rooftops or open over a third to less than 10,250 gallons 2007 21,489,902 areas. It captures and directs runoff per second. 2008 31,234,361 from a 17.7 square mile watershed into a large system of lined basins. 2009 0** KERP is designed to reduce the peak KERP retains over 114 million gallons flow rate from 85,260 gallons per 2010 28,847,627 (350 acre-feet) of water in the con- second to 35,840 gallons per second, 2011 16,363,011 structed ponds. This harvested water during a 100-year storm. 2012 11,988,074 is then available for irrigation needs.

Pima County’s investments in flood 2013 41,322,247 Economic Benefits control infrastructure (KERP, Rodeo, 2014 48,674,288 KERP’S key objectives include the Kolb Road, Arroyo Chico and Cherry 2015 61,181,975 harvesting of stormwater to improve Field detention basins) resulted in the 2016 103,667,096 ecosystem function and to meet prevention of mass flooding during a surrounding irrigation needs. Storm- 2017 38,604,462 September 15, 2011 storm. In a Sep- water is harvested and re-circulated * Maintenance operation issues through the stream courses in the tember 22, memorandum to the Pima ** Lack of rain and stormwater County Board of Supervisors, Pima basin to support environmental bene- County Administrator, Chuck Huckleberry described fits. Stormwater is also diverted and used to irrigate the value of the County’s flood control infrastructure. the Kino Sports Complex ball fields, other turf areas, Huckelberry explained that if such infrastructure had and landscaping at University Medical Center South, not been in place on September 15, “…there would Herbert Abrams Public Health Center, Sam Lena have been significant flood damage in developed Park, and the Public Defenders, Juvenile Court and Tucson, including the downtown area.” Adult Probation buildings along Ajo Way. 8 An annual average of 78 acre-feet of excess storm- Public access to the basin itself is prohibited. Those water is harvested for the sports complex and other who are found fishing in the basin will lose their fish- surrounding area landscape irrigation needs. In ad- ing licenses and will be fined. dition, the vegetation and habitat amenities in KERP are sustained by an annual average of 200 acre-feet of The Kino Sports Complex, the largest professional stormwater. sports and entertainment venue of its kind in Pima County, was constructed If not for the use of south of the basin in 1997. reclaimed water and The complex uses KERP- stormwater that flows harvested stormwater into the project, the KERP for irrigation of six soccer basin, sports complex and fields and other turf areas. nearby landscape would be irrigated with potable The Pima County Stadium water. Based on the value District manages the Kino of potable water calcu- Sports Complex and Sam lated at the commercial Lena Park. These facilities rate, the use of stormwa- are available for youth, ter has provided taxpayers high school and collegiate a cumulative savings of sports, social gatherings, $5.16 million dollars since concerts and community project construction. It is events. projected that the $6 mil- lion local share of the KERP construction cost will be The Loop paid off by 2018 KERP and Kino Sports Park are accessible from the Loop. The Loop is 100+ miles of motor vehicle-free maintained paths around the metropolitan area. Public Recreation Benefits It accommodates pedestrians, cyclists, skaters and Proposals to add recreational features to the Ajo De- equestrians. The Loop links the Tucson area with tention Basin came within a decade of its completion. Marana and Oro Valley and connects the Rillito River In 1986, Pima County constructed Sam Lena Park Park, the Santa Cruz River Park, the Julian Wash adjacent to the basin. Sam Lena Park has two lighted Greenway, the Harrison Greenway and the Pantano softball fields, a basketball court, nine ramadas with River Park. grills, public restrooms and drinking fountains. KERP included a 2.2-mile paved path encircling the basin for walking, jogging, bicycling and wildlife viewing.

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KINO SPORTS COMPLEX AREA MAP

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Basketball COUNTRY CLUB ROAD Court NORTH North GRAND Clubhouse KERP Parking J NORTH STAND ASO Kino Environmental N LIGHTED VIS Restoration Project Covered TA Mulcahy Y Batting COMPLEX at Kino Cages

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Multi-Use Path Multi-Use FIELD NORTH Small Deep Pond Pond STADIUM 1 LIGHTED Basin Irrigation Outlet Pond Parking

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KINO BOULEVARD Veterans Memorial 2 3 4 Plaza

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Parking Stadium FIELD Parking Clubhouse Kino Veterans 3 Memorial SOUTH PRESIDENT STREET FIELD Stadium

FIELD FORGEUS AVENUE 2 5 Batting Cages COMPLEX Gravel Parking LIGHTED Multi-Use Path FIELD Parking Gate A Observation Gate B FIELD Tower 4 LIGHTED Snack Bar Batting COUNTRY CLUB ROAD 6 Cages South LIGHTED Club House Parking FIELD Covered Batting Cages 7 DISTRICT STREET LIGHTED FIELD FIELD W E 10 S T S 8 ER V IC FIELD th E Pa D e R s FORGEUS AVENUE U I i- BENTLEY ROAD ult FIELD V 12 M E Gravel LIGHTED Parking INTERSTATE 10 9 FIELD 11 Gravel LIGHTED Parking South Maint. MILBER STREET Building

0 500 1000 Gravel Parking Parking Parking Scale in Feet KINO SPORTS COMPLEX Exercise Stations Fields AREA MAP Streets / Access Roads Gravel Ponds & Channels Bus & RV Parking Parking Complex Buildings KERP is embedded within a complex of sports facilities, Pedestrian / Bike Path municipal service buildings, and health services Kino Environmental Pima County Stadium District Buildings Restoration Project Administration O ces facilities, most notably the UA Medical Center-South Fences Campus, which serves residents south of downtown Tucson. 11 Environmental Benefits Cottonwood Willow KERP provides open water, riparian habitat and upland Riparian trees like cottonwoods, ash and narrow-leaf plant communities. A riparian habitat is made up of willow depend on abundant near-surface water avail- the plants and animals associated with streams and able in river bottoms and banks. Birds attracted to this rivers. In the desert, these areas are important to many lush habitat are the Wilson’s Warbler, the Black Phoe- wildlife species. Eighty percent of Arizona’s wildlife be, the Song Sparrow and the White-winged Dove. species depend on the resources of riparian areas. The terrain in KERP, visible from a paved walkway around Mesquite Bosque the perimeter, has several different environments and A dense stand or “forest” of mesquite trees is called a plant communities. bosque. Mesquite trees are especially adapted to our dry climate, sending taproots down as deep as 150 Open Water feet to reach water during times of drought. Mesquite In ponds and lakes, open water is the habi- bosques provide shade and shelter for wild- tat found beyond the shallow water and life and other plants. Mesquite seeds are rich plants of the shore. Diving ducks feed in in protein and are an important food source open water, seeking out water insects and for many animals. Mesquite bosque birds to aquatic plants. Three species of native toads look for are the Gila Woodpecker, Ladder- utilize the ponds including the Great Plains backed Woodpecker, Vermilion Flycatcher toad, the Great Plains Narrow-mouth toad and the White-crowned Sparrow. and the Sonoran Desert toad. Sustainable populations of native aquatic invertebrates Grassland provide natural mosquito control. Open This habitat contains native grasses and small water birds include the Mallard, the North- herbaceous plants. It provides forage, nest- ern Shoveler, the Ringnecked Duck and the ing and cover for reptiles, small mammals, Belted Kingfisher. birds and insects. Grassland birds in the area include Burrowing Owls and various finches and spar- Marsh rows. Marsh vegetation communities are found in wet- lands, where land meets water at the edge of a Arizona Uplands pond, lake or river. Wildlife thrives in wetland habitat Tucson is located in the Arizona Upland Subdivision of because of the abundant water and the cover pro- the Sonoran Desert where Palo Verde trees, saguaro, vided by wetland plants such as reeds and cattails. cholla and prickly pear cacti are common. Desert birds Migratory waterbirds rely on wetlands as stopover nest and forage within the protection of these thorny points during their long journeys in the spring and plants. Other animals such as javelina, jackrabbits and fall. Wetland birds in the area include the American desert tortoises feed on the cactus pads and fruit. Coot, Red-winged Blackbird, Great Blue Heron and Arizona Upland birds include the Red-tailed Hawk, the the Black-necked Stilt. Gambel’s Quail, the Curve-billed Thrasher, the Cactus Wren and the Greater Roadrunner. 12 CONCLUSION

13 fter its completion in 2001, the KERP had ship. These multiple objectives were an important A effectively modified the existing Ajo De- departure from earlier visions such as the Ajo Deten- tention Basin by integrating a harvested tion Basin with its single purpose (flood control). Like stormwater storage component capable of sustain- The Loop trail, which connects multiple sections of ing native habitats for wildlife, plus providing irriga- recreational paths throughout the greater Tucson tion for Kino Sports Complex and other landscaping area into a single path, KERP has proven that integra- needs. So successful are KERP’s water harvesting and tion and connection can create something that is restoration features that they serve as an example much larger than the sum of its parts. Given limited for future stormwater harvesting projects. space within an urbanized environment, projects that meet multiple needs such as KERP will become The vision of KERP’s planners resulted in the realiza- increasingly needed and successful, greatly benefit- tion of multiple goals: flood control, wildlife habitat, ing our community and our environment. recreation, cost savings and environmental steward-

Stormwater used in and harvested from the KERP basin has saved taxpayers an average of $390,000 per year in irrigation costs (calculated at the commercial potable rate). 14 Board of Supervisors Richard Elías, Chairman, District 5 Ally Miller, District 1 Ramón Valadez, District 2 Sharon Bronson, District 3 Stephen W. Christy, District 4

Pima County Administrator Chuck Huckelberry Communications Office • March 2018 • #3226ea