The Maeveen Marie Behan Conservation Lands System (CLS) reconciles the need to plan and protect the tax base and provide opportunities for economic growth with the biological goal of the Sonoran Desert Conservation Plan (SDCP). The biological goal of the SDCP is to:
Ensure the long-term survival of the full spectrum of plants and animals that are indigenous to Pima County through maintaining or improving the habitat conditions and ecosystem function necessary for their survival.
As a result of the Sonoran Desert Conservation Plan, the County comprehensive plan is now guided by the CLS “roadmap” that was developed with the assistance of over 150 contributing scientists, and based on local studies of the land.
The CLS categories are based on their values in supporting and representing biological diversity. Each of the categories has an associated conservation guideline policy, which encourage development outside of the CLS designations. The CLS guides the acquisition of open space and habitat conservation lands by Pima County. Since its adoption date in 2001, Pima County has purchased over 180,000 acres within the CLS (73,000 acres fee-owned lands, and 114,000 acres of leased ranch lands). Funding for acquisition of conservation lands was provided by the voters in the 2004 Open Space Bonds. See a Flickr gallery of photographs of acquired lands here.
The actual CLS land-use policies apply only to discretionary actions of the Pima County and the Pima County Regional Flood Control District Boards, but the more powerful idea of maintaining an interconnected landscape for biological conservation has also motivated state and federal partners to set aside conservation lands. Today nearly 60% of the CLS in all jurisdictions is in some kind of conservation reserve status, where the land is managed to protect natural open space. The BLM has improved the conservation status of over 174,000 acres of land, which includes the world’s principal population of the Gila topminnow, and the remaining wild (i.e. not transplanted) bighorn sheep population. The U. S. Bureau of Reclamation purchased mitigation lands within the CLS for long-term protection, and state agencies have worked with Pima County and other local governments on improving habitat conditions and improving wildlife movement opportunities across roadways. Oro Valley adopted an ordinance that strengthens protection of Important Riparian Areas, and worked with Pima County to reserve additional CLS land in their planned annexations. City of Tucson is working on habitat conservation plans for the southeastern Tucson Basin lands and Avra Valley.
In August of 2009, an analysis was performed on how effectively County-managed lands contributed to conservation goals for particular species and landscape features significant to the SDCP. The analysis found that considerable progress had been made in meeting the SDCP biological goals, and the county’s ranch acquisitions had prevented fragmentation of habitats next to existing protected areas.