POISON SPRINGS/ SIERRA ANCHA, DAGGER CHRYSOTILE, HAYSTACK BUTTE, SEDOW, and HICKS/PIKES PEAK ALLOTMENTS STREAM CHANNELS AND RIPARIAN AREAS EXISTING CONDITIONS Lynn Mason and Janet Grove July 2011, updated October 2012 Updated January 28, 2013 INTRODUCTION Area of Analysis This project area incorporates seven allotments from two districts. The Poison Springs and Sierra Ancha Allotments are being managed as one allotment. Those, along with the Dagger Allotment, are located on the Tonto Basin District. The remaining four allotments, Chrysotile, Haystack Butte, Sedow and Hicks-Pikes Peak, are located on the Globe District. All of the allotments are located along the Salt River, beginning at the eastern Forest boundary on the Chrysotile Allotment and ending at Roosevelt Lake on the Poison Springs Allotment. The project area lies within twenty-one 6th code watersheds. The watersheds and their condition are listed in Table 1. There are approximately 374 miles of named streams on the USGS 1:24,000 topographic quadrangles and unnamed streams that support riparian vegetation within the project area. There appear to be at least as many miles of unnamed streams delineated as blue lines on the USGS topographic quadrangles. These unnamed streams are the ephemeral and intermittent tributaries to the named streams. These channels are primarily headwater channels dominated by upland vegetation or ephemeral washes. They provide important functions relating to water quantity, water quality, the flood regime, hydrological connectivity, riparian vegetation and wildlife habitat within the watershed (Meyer et al. 2003, Levick et al. 2007). Historic Conditions The existing condition of watersheds, stream channels and riparian areas has been affected by many factors, both natural disturbances and human activities. The natural disturbances, drought, fire and floods, have likely been exacerbated by human activities. Historic over-grazing has had the most extensive effect on watersheds, stream channels and riparian areas. Cattle were introduced in the late 1870s following the Civil War and the subjugation of the Apaches. By 1891, one and a half million cattle had been brought to Arizona (Allen 1989). The range was severely overstocked. The trails formed by livestock on the uplands and next to the stream channels were the beginnings of gulleys. Trampling and compaction in the uplands caused deterioration of the vegetation and soils. Vegetation along stream channels was removed by cattle. In 1892-93 a severe drought occurred that caused the death of many cattle and had a detrimental effect on an already deteriorated range (Allen 1989). 1 In 1875, silver was discovered in Richmond Basin. Subsequently, the Mack Morris Mine was established and a ten-stamp mill was installed on Pinal Creek to reduce its ore (Dobyns 1981). There were also smelters and mills in operation in Globe and Miami. In the early 1880s, when the production of copper surpassed silver and gold, three water jacket furnaces were built on Pinal Creek (Dobyns 1981). All these mining operations required huge amounts of wood for fuel and building purposes which resulted in severe depauperation of timber in the surrounding areas (Dobyns 1981), including the Hicks-Pikes Peak Allotment. Pinal Creek was also subjected to placer mining (Dobyns 1981). Other activities connected with prospecting and mining operations, including grazing and removal of vegetation, also impacted areas of the Chrysotile Allotment (FS 2210 range files). When the rain came, there was little ground cover left to slow the water. In February 1891 two large floods occurred in the Gila River watershed, and had a devastating effect on the channels in the Pinal Creek watershed (Dobyns 1981). Overland flow and subsequent erosion of the uplands overwhelmed steams. Soil surface layers and large areas of floodplain were washed away. Stream channels downcut, widened, and lost connectivity with the water table, leaving the wide, unstable, dry channels existing today. The Forest Service Range Management Planning (2210) files located at the Tonto National Forest Supervisor’s Office in Phoenix indicate that all of the allotments in the project area had been severely over-grazed by the 1940s. Cattle concentrated in the channel bottoms, flat areas and near water. There were few off-channel waters so the cattle depended on springs, streams and the Salt River for water. Many of the springs were fenced and used as traps, causing severe erosion and loss of vegetation. A 1944 Forest Service range inspection includes a lengthy report that contains information about several of the channels on the Radium Allotment which is adjacent to Hicks-Pikes Peak, to the south. The report states that older stockmen claimed the washes, at one time, supported sodded-over bottoms and the small gravelly streams ran nearly yearlong. By 1944, the channels were getting washed out by floods because of poor upland condition and cattle were trailing down channels and causing damage. The condition of Negro Wash, which also occurs on the Hicks-Pikes Peak Allotment, was “deplorable”. It was depleted of perennial grasses, though some bunch grasses were present (possibly deergrass). This is certainly the case for channels on the other allotments as well. Best Available Science The best available science was used for this analysis. The analysis is based primarily on data collected during past and present field visits conducted for the purposes of monitoring riparian use, stream channel classification, condition assessment and inspections. Field methods and protocols used can be found in the following documents: Utilization studies and residual measurements (ITT 1996), Riparian Area Management Utilization Guidelines (McBride and Grove 2002), Applied River Morphology (Rosgen 1996), Stream channel reference sites: an illustrated guide to field technique (Harrelson et al. 1994), Tonto Stream Assessment Method (Mason and Grove 1999). Other current literature used is listed under references. This information was used in conjunction with the principles of hydrology and riparian ecology and constitutes consideration of the best available science. 2 EXISTING CONDITIONS Presently, of 374.14 miles of stream channels, including those named on the USGS topographic maps and those identified as supporting riparian vegetation on the National Wetland Inventory (NWI) maps, there are approximately 70 miles of stream channels that support obligate riparian vegetation. Based on the 2210 Forest Service reports, and associated changes in both upland and riparian vegetation, this extent of riparian vegetation has been reduced from historic conditions (Croxen 1926, Haskett 1935, Heffernan 2008). The potential to restore and increase the acreage of riparian vegetation is unknown, but likely. On these allotments, most of the stream channels evaluated in the field are in unstable or impaired condition (Table A3). Riparian areas and springs have been relied upon as the primary source of livestock water for many years causing stream channels and adjacent riparian areas to receive concentrated grazing pressure. Appendix A summarizes all the data available for the streams and riparian areas of the project area. This data provides the source of information for the description of steams and riparian areas chosen as key reaches for the project area. Recent Flood Events Stream channels are dynamic ecosystems that are constantly being changed by the water and sediment flowing through the system. These changes obey the natural forces of gravity, friction and fluid cohesion (Janicke 2000). A stable (Mason and Johnson 1999), or properly functioning (Barrett 1993), stream channel is dependent on its ability to resist the forces of erosion (Janicke 2000) and will maintain its dimensions (width/depth ratio, gradient, sinuosity) over time without excessive erosion or deposition (Rosgen 1996). A healthy riparian ecosystem contributes to channel stability by increasing resistance, thereby reducing flood peaks, trapping sediment and increasing groundwater recharge (Briggs 1996). Modifications that cause removal of vegetation will lower the channel’s resistance to erosion and lead to an increased frequency and magnitude of flood impacts (Trimble and Mendel 1995, Rosgen 1996, Janicke 2000). Most of the stream channels in the project area are in impaired or unstable condition (Mason and Johnson 1999) in a large part due to lack of riparian vegetation. These streams are less able to resist the erosive forces of flood waters and will begin to erode with smaller events which consist of lower water velocities (Janicke 2000). When large events with high water velocities occur, the channels “blow out”, causing heavy loss of riparian vegetation and severe erosion and/or aggradation. In late January 2008, a weather system off the west coast moved into Arizona that tapped tropical moisture from the south. It brought high precipitation along the Mogollon Rim and the Upper Gila River watershed that caused flooding (Stall and Lader 2008). Stream gages within and near the project area recorded high flows (Table 1). 3 In mid-January 2010, three low pressure systems passed through Arizona within a week causing intense rainfall and record flooding south and west of the Mogollon Rim (NOAA 2010). Stream gages within and near the project area recorded record high flows (Table 1). Table 1. Peak flow data for gages within and near the project area (USGS 2011a). Gage Date Flow (cfs) Comment Salt R. near Chrysotile 1-28-2008 55,300 6th highest flow of record 1-22-2010 37,000 15th highest flow of record Salt R. near Roosevelt 1-28-2008 81,300 9th highest flow at the time 1-22-2010 88,300 8th highest flow of record Cherry Creek near Globe 1-28-2008 10,300 3rd highest flow at the time 1-22-2010 17,700 highest flow of record Pinal Creek at Inspiration Dam 1-28-2008 2520 5th highest flow at the time 1-22-2010 5330 2nd highest flow of record Given the initial condition of the stream channels and the magnitude of two rainfall/flooding events at such close intervals, many of the streams within the project area have been “blown out” by the recent floods.