On December 14, 2010, the U.S. Fish & Wildlife Service published its final rule (PDF) redesignating critical habitat for the Santa Ana sucker, a small fish species occurring in watershed draining the San Gabriel and San Bernardino mountains of southern California.  The Final Rule designates a total of 9,931 acres across San Bernardino, Riverside, Los Angeles, and Orange counties and is comprised of 7,097 acres in the Santa Ana River, 1,000 acres in the San Gabriel River, and 1,233 acres in Big Tujunga Creek.  The Final Rule increased the sucker’s net critical habitat by approximately 1,026 acres over the Service’s 2005 rule (PDF).

The Santa Ana sucker was listed as threatened in the Santa Ana River, San Gabriel River, and Big Tujunga Creek in 2000.  In 2005, the Service designated critical habitat for the sucker in the San Gabriel River (5,765 acres) and Big Tujunga Creek (2,540) totaling 8,305 acres.  In the 2005 final rule, the Service did not designate critical habitat for those portions of the Santa Ana River covered by habitat management plans–the Western Riverside Multiple Species Habitat Conservation Plan and the Santa Ana Sucker Conservation Program–consistent with established policy.  Nor did the Service designate portions of the Santa Ana River not covered by habitat management plans, which are also unoccupied.  In its 2005 final rule the Service explained that although these areas provide necessary flood conditions and sediments and small cobblestones that is passes to the downstream area occupied by the sucker, those features alone are not sufficient to meet the statutory required statutory standard –“essential to the conservation of the species” — particularly in light of Congressional direction to be “exceedingly circumspect” in designating critical habitat outside of areas currently occupied by the species. 

In its 2010 Final Rule the Service performs an about-face, which is evident in new critical habitat designation of 7,097 acres in the Santa Ana River.  The Service lifts the exclusion of those portions of the Santa Ana River subject to the Western Riverside Multiple Species Habitat Conservation Plan (approved in 2004) and the Santa Ana Sucker Conservation Program (2000) because they have not yet been sufficiently implemented to yield benefits to the sucker.  The Service continues its reversal by designating as critical habitat upstream unoccupied areas in the Santa Ana River based on necessary water flows and coarse sediments deemed essential for the conservation of the species. 

Acreage reductions in the San Gabriel River and Big Tujunga Creek units, as well as mapping changes within the Santa Ana River critical habitat unit, reflect refined mapping capabilities, changes to the criteria used to identify critical habitat, such as a slope limit of 7 degrees, and reevaluation of the 2005 rule, which, was compelled by court order from the U.S. District Court of the Central District of California as a result of a stipulated settlement agreement with California Trout and other environmental groups.