Data Collection Report - Flood Control District of Maricopa County

upstream, and downstream of the confluence of the Gila and Salt riversat 115 th Avenue, and along the Agua Fria River near Highway 85 southto its confluence with the Gila River. The Tres Rios constructedwetlands is located adjacent to the Salt River floodplain at 91 st Avenuewastewater treatment plant. Wetland vegetation in and downstream ofTres Rios is patchily distributed and fairly diverse, containing submerged,emergent, and floating vegetation such as cattail (Typha latifola),bulrush (Scirpus sp.), rushes (Juncus spp.), sedges (Carex spp.), andreed (Phragmites sp.). The artificial wetland contains native and exoticaquatic and riparian vegetation and animals, and is supported byreclaimed wastewater from effluent.Special interest species that may occur in or use the natural aquaticcommunity within the project area are Yuma clapper rail, great egret,snowy egret, and western least bittern.Sonoran Riparian Woodland. This community occurs near the edgeof the floodplain of the Agua Fria, Salt, and Gila rivers. It ischaracterized by dense, tall trees and shrubs growing along perennial orintermittent water courses. Typical plants include: Fremont cottonwod(Populus fremonti), Goodding willow (Salix gooddingii), tree tobacco(Nicotiana glauca), seep willow (Baccharis salicifolia), and salt cedar(Tamarix sp.).Special interest species that may occur in this vegetation communitywithin the project area are southwestern willow flycatcher, great egret,and western yellow-billed cuckoo.Sonoran Riparian Scrub. Known also as Xeroriparian 1 Mixed Scrub,this community typically occurs as a linear corridor of sparse to denseshrubs and trees lining washes and growing in floodplains. It oftenoccurs adjacent to Sonoran Interior Strand. Typical plant speciesinclude: mesquite, blue palo verde (Cercidium floridium), catclaw acacia(Acacia greggii), desert willow (Chilopsis linearis), tree tobacco,canyon ragweed (Ambrosia ambrosioides), desert broom, globe mallow,wolfberry (Lycium berlandieri), desert hackberry (Celtis pallida), andsmoke tree (Psorothamnus spinosus). The greater abundance ofresources provided by the vegetation increases the value of this and otherriparian communities over the adjacent upland community for manyspecies.Special interest species that may occur in this vegetation communitywithin the project area are Sonoran desert tortoise.Sonoran Interior Strand. Strand communities are often adjacent toxeroriparian communities and are narrow, but may occasionally begreater than 100 feet wide. Strand communities are typically lined withsmall trees found in Sonoran Riparian Scrub. Common plants growingin the strand community include burrobrush, desert broom, snakeweed,Russian thistle (Salsola sp.), burroweed, canyon ragweed, cocklebur(Xanthium strumarium), fluff grass, cheat grass (Bromus tectorum), andmany other short-lived perennial and annual species.No special interest species are expected to exclusively occur in thisvegetation community within the project area.Special Status SpeciesEighteen species are evaluated herein. Thirteen of these species (tenanimals and three plants) are listed by the FWS as threatened orendangered in Maricopa County. The remaining five animals are listedby AGFD. While plants protected only by the state of Arizona are alsolisted by AGFD, the Arizona Department of Agriculture is responsiblefor administering the Arizona Native Plant Law. A description ofregulatory status and protection for each applicable agency follows.- Federal Threatened and Endangered Species. Species listed orproposed to be listed for protection under the EndangeredSpecies Act (ESA) as endangered, threatened, or candidate. TheESA specifically prohibits the “take” of a listed species. Take isdefined as “to harass, harm, pursue, hunt, shoot, wound, kill,trap, capture, or collect, or to engage in any such conduct.” 2The FWS maintains a designation of proposed and listed speciesknown to occur in each Arizona county.- Wildlife of Special Concern in Arizona. The AGFD formerlylisted 116 species as extinct, endangered, threatened, andcandidate in Arizona (AGFD 1988). While the terminology usedwas identical to that used by FWS, the AGFD categories wereadvisory and provided no legal protection for take of suchspecies or modification of their habitat. The latter pointscontrasts the FWS list. To avoid confusion, AGFD is currentlyrevising and reissuing their list as “Wildlife of Special Concern inArizona” without using the terms endangered or threatened. The1Associated with an ephemoral water supply and typically contain plant species also found in uplandhabitat, although riparian plants are commonly larger and occur at higher densities than those in adjacentuplands.2 Endangered Species Act, Section 3, paragraph 19. Further, 50 CFR § 17.3 defines “harm” as “anact which actually kills or injures wildlife. Such act may include significant habitat modification or degradationwhere it actually kills or injures wildlife by significantly impairing essential behavior patterns, includingbreeding, feeding, or sheltering.”DIBBLE & ASSOCIATES 38 DURANGO ADMPDATA COLLECTION REPORT