Black Farm Preserve Baseline Inventory
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BLACK FARM PRESERVE (Previously known as the Stambaugh Property) BASELINE INVENTORY September 2004 COMPILED BY Salt River Project Siting and Studies Division Environmental Services Department P. O. Box 52025 Phoenix, Arizona 85072-2025 CONTENTS Summary………………………………………………………… ……………………… ii Conservation Values Based on Baseline Inventory……… …………...………… ii Management Issues Based on Baseline Inventory……… …………….………… ii I. Introduction…………………………………………………… ……………………… 1 A. Purpose………………………………………………… ………..……………. 1 B. Methods………………………………………………… ……….……………. 1 C. Report Organization…………………………………… …………..…………. 1 II. General Description…………………………………………… …………..…………. 2 A. Geographical Setting…………………………………….………..…………… 2 B. Conservation Values on the Property…………………………………………. 6 III. Site Resources…………………………………………………………………………. 6 A. Geology ……………………………………………………………… ………. 6 B. Soils…………………………………………………………………………… 7 C. Hydrology……………………………………………………….……………. 9 D. Vegetation……………………………………………………..………..……. 11 E. Wildlife……………………………………………………….……………… 15 F. Cultural Resources……………………………………………..……….……. 18 G. Additional Resources…………………………………………..……….……. 20 H. Land Use and Management………………………………………………….. 20 I. Property Improvements and Legal Considerations…………….……….……. 21 References………………………………………………………………….…………… 26 FIGURES Figure 1. Aerial Photograph…………………………………………………………… 3 Figure 2. Regional Setting……………………………………………………………... 4 Figure 3. Local Setting………………………………………………………………… 5 Figure 4. Soils................................................................................................................. 8 Figure 5. Vegetation Communities……………………………………………………. 14 Figure 6. Land Ownership…………………………………………………………….. 22 Figure 7. Property Improvements and Photo Point Locations ....................................... 24 APPENDICES Appendix A: Permanent Photo Point Location Descriptions and Documentation Appendix B: Site Photographs Appendix C: Plant Species Appendix D: Wildlife Species Appendix E: Report Preparers and Contributors i SUMMARY OWNER/CONTACT: Salt River Project Agricultural Improvement and Power District PAB352 P.O. Box 52025 Phoenix, Arizona 85072-2025 PROPERTY LOCATION: Property is located off of State Highway 77, about six miles south of Dudleyville in Pinal County, Arizona. ACREAGE: 137 acres, total 30 acres stream bottomland 107 acres irrigated agricultural land MITIGATION CREDITS: 95 acre-credits, total 30 acres riparian habitat 65 acre-credits water rights/buffer lands ZONING: General Rural CONSERVATION VALUES BASED ON BASELINE INVENTORY The Property is important for conservation because it possesses: an annual surface water right from Aravaipa Creek in the amount of 1,692.5 acre-feet from January 1 to December 31, dating back to December 28, 1865, to be transferred to an instream flow right for purposes of sustaining riparian-related wildlife habitat riparian habitat associated with Aravaipa Creek that has the potential to provide wildlife habitat. MANAGEMENT ISSUES BASED ON BASELINE INVENTORY Some management issues that could affect the Conservation Values adversely include: Extensive groundwater pumping from the alluvial aquifer in the vicinity of the Property Trespass livestock or recreationists (i.e. off-road vehicles, hunters) Wildfires in the riparian area Development pressures from adjacent landowners Noxious weeds on the Property and adjacent areas I. INTRODUCTION A. PURPOSE The purpose of this baseline inventory is: (1) to summarize the physical and ecological characteristics and conditions of the Property; and, (2) to document and record existing conditions and Conservation Values on the Property. Conditions on the Property have been documented through surveys, inventories, monitoring, photographs and literature review. B. METHODS AND SOURCES OF INFORMATION The baseline inventory was compiled from a number of sources. Salt River Project Agricultural Improvement and Power District (“SRP”) staff and consultants conducted several site visits to document ecological and physical characteristics of the Property. Catherine May, SRP historian, used the Land Use History methodology to compile the pre- history and history of the area. Richard Anduze, SRP archaeologist, expanded on May’s work based on a site reconnaissance and review of the literature. John Felty, SRP Land Agent, provided general information about the Property. Additional information about site characteristics came from an Environmental Site Assessment that was conducted by Chris C. Robertson, R.G., for SRP. Ruth Valencia and Lesly Swanson, SRP biologists, inventoried plants and wildlife on the Property and consulted field guides and other literature. SRP spoke to personnel from several government agencies to obtain information, including Dr. Francis E. Northam at Arizona Department of Agriculture (ADOA), Sabra Schwartz at the Arizona Game and Fish Department’s (“AGFD”) Heritage Data Management System (“HDMS”) and Winnie Chen at the Natural Resource Conservation Service (“NRCS”). Other sources of information used for this inventory include: Arizona State Land Department records; Pinal County Department of Planning and Development’s website; the Arizona Geological Society (“AGS”) website, publications and maps; the Natureserve website; U. S. Geological Survey (“USGS”) website; Arizona Department of Water Resources (“ADWR”) publications; Arizona State University, Geology Department website; and, Pinal County publications and website. C. REPORT ORGANIZATION This report presents a summary of the information gathered for the baseline inventory and describes the results of SRP’s evaluation of the Property’s resources and Conservation Values. The report is organized into four narrative sections and five appendices. Following the Summary and Introduction, the General Description section provides information on the setting and history of the conservation project. The Site Resources section summarizes the ecological and cultural resources, land use and management, property improvements and legal considerations related to the Property. Appendix A contains descriptions of permanent photo points on the Property and Appendix B contains photo documentation of the Property. Appendix C is a list of plant species identified during multiple site visits in April through August 2004. Appendix D is a list of 1 wildlife species identified during multiple site visits to the Property and from literature. Appendix E presents a list of the report preparers and contributors. II. GENERAL DESCRIPTION The Property is located at the confluence of Aravaipa Creek and the San Pedro River. Aravaipa Creek flows in a westerly direction through the northern portion of the Property. The remainder of the Property lies to the south of Aravaipa Creek and is located on the adjacent floodplain and terrace. At this location, the creek is ephemeral, flowing on the surface in response to large run- off events in the watershed (ADWR 1991, ADWR 1994, Ellingson 1980). The channel is wide and shallow, sometimes braided, and contains coarse-grained (pebbles and cobbles) point bars (Richards 1982). Vegetation within the creek bottom is dominated by burro brush (Hymenoclea sp.) and can best be described as xeric riparian or riparian strand. A small stand of mesquite (Prosopis velutina) trees grow on the adjacent terrace. Composition and diversity of riparian vegetation in this stream channel have been negatively impacted from years of livestock grazing, from falling groundwater levels due to off-channel pumping and from variable stream flows. For more than a century, the adjacent river terraces have supported irrigated agriculture and livestock grazing. On this Property, approximately 100 acres of the terrace were irrigated for agricultural purposes up until SRP’s purchase. Water is supplied to these fields by a well that accesses the alluvial aquifer. A small ranch house and two outbuildings are situated in the center of the agricultural fields. A row of pecan trees lines the entrance road to the Property and a large Arizona walnut tree marks the location of a human burial in the eastern field. An aerial photograph taken in November 2003, shown on the following page, provides a general overview of the condition and characteristic of the Property (see Figure 1). A. GEOGRAPHICAL SETTING The Property is located in southeastern Pinal County about six miles south of Dudleyville, along Highway 77, in Sections 9 and 10, Township 7 South, Range 16 East of the Gila and Salt River Base and Meridian. The Property is situated within the Arizona upland subdivision of the Sonoran Biogeographic Province of the Southwest (Brown 1994) in an alluvial valley at the mouth of Aravaipa Creek. The Property includes 137-acres and is irregular in shape. It encompasses cultivated land, vacant land and part of the Aravaipa Creek drainage channel. Elevations on the Property range from approximately 2,160 feet above sea level at the northwest corner to approximately 2,200 feet above sea level near the southeastern corner. Based on weather data from the Winkelman 6S weather station (029420), average total precipitation in the area is 13.9 inches. A little over half of this occurs during the summer months from July through October as the result of late afternoon or early evening thunderstorms that originate from northerly flows of warm tropical air. Summer storms are usually intense over the mountains producing turbulent wind and localized heavy showers. Conversely, winter precipitation is less severe but longer lasting, originating from mid- latitude