This article examines the influence of climate variability and accelerated forest thinning on runoff in ponderosa pine forests in the Salt and Verde River watersheds in central Arizona. The effects of thinning treatments were examined over 15-, 25-, and 35-year periods. Over the course of treatments, cumulative runoff on thinned forests was about 20% greater than un-thinned forests, regardless of whether forest thinning occurred in a dry or wet period. Runoff gains were temporary and modest when compared to total annual flows in Salt-Verde (≤3%). Nonetheless, additional runoff from thinning could help offset projected declines in snowpack due to warming, augment river flows on a seasonal basis, improve conditions for water dependent natural resources, as well as provide incidental benefits to downstream users.Download file (847KB)
Every June groups of volunteers walk the entire 170 mile length of the San Pedro River and record where it is wet and where it is dry during the hottest, driest time of the year. Fifteen years’ worth of data on summertime surface flows in the San Pedro River within the San Pedro Riparian National Conservation Area (SPRNCA) are now available as an animation. Watch to see the changes in surface flow over time. These observations were recorded by citizen scientists through the Wet/Dry Mapping project- a collaboration between TNC and the Bureau of Land Management on this particular reach of the San Pedro River. Follow this link to see what they found from 1999 to 2014 on the approximately 50 miles of the San Pedro River that flows through the SPRNCA.
Notes about the data and animation:
1. Use the play, pause, and advance buttons at the bottom to view the animation.
2. Use the plus or minus keys to zoom in on portions of the river.
3. Survey dates varied from year to year, but have been standardized to June 29 for purposes of this animation.
4. Although the animation time scale at the bottom indicates a one year date range, the data shown is actually the annual standardized June 29th survey date. To make the scale date appear as that one point in time, click on and drag one of the time markers on top of the other.
The San Pedro River wet/dry mapping dataset is a community effort to track the river’s health by monitoring the persistence of surface water during the driest time of each year. It is created by recording the end points of every wet section of the San Pedro River during June each year. Maps depict the wet portion of the San Pedro River.
Part of the Ecology and Society journal’s special issue on adaptive management, this paper summarizes the essential lessons learned from 15 years’ of collaboration and strong commitment from public stakeholders at Las Cienegas National Conservation Area in southeastern Arizona. The paper describes key components of a program that continues to expand and attract expertise and investment by stakeholders, including: (1) agreement on watershed health goals with measurable resource objectives; (2) gathering relevant and reliable scientific information; (3) creating mechanisms to incorporate new information into decision-making; and 4) using shared learning to improve both the process and management actions. Since 1998, this approach has proved successful for resolving challenging issues and has focused public and private investment on improving land health. Other papers in this special issue provide context and additional examples of adaptive management in practice, including an effort at the Agua Fria National Monument that is being modeled after work at Las Cienegas; all papers can be found here .Download file (1.3MB)
Riparian grasslands dominated by big sacaton (Sporobolus wrightii) once covered floodplains across the southwest, but have been reduced to some 5% of their historical extent. Sacaton stands that remain provide key resources for watershed function, wildlife, and livestock—yet may need special management to sustain these benefits. This report describes mapping methods and management recommendations that can be applied to riparian grasslands throughout the region. By examining sacaton grasslands in the Las Cienegas National Conservation Area, this project also refines methods for evaluating ecological condition, and provides managers at this site with detailed maps of both high-quality habitat and restoration needs.Download file (5.6 MB)
Central Arizona’s Verde River is a natural resource that is critical to the regional economy, environmental sustainability, and quality of life. The river’s future is uncertain, however, as there are still unresolved issues over how we grow while sustaining a healthy river. This report examines possible futures for the Verde River within the Verde Valley and provides information for stakeholders and decision-makers on the river’s resources, economic value, and tools for promoting sustainable water management. The report also summarizes three water management case studies from around the western U.S. that characterize the range of water management options that communities have adopted.Download file (4 MB)
Published in Environmental Management, this article describes a simple method for monitoring the flow status of interrupted perennial streams, with the example of a 12-year effort on the San Pedro River. We found that surface flow increased for parts of the river, apparently due to conservation actions, while other parts were stable or may have declined. The data allowed us to map areas with surface flow in every year, totaling 32% of the river length through the San Pedro Riparian National Conservation Area (SPRNCA). These maps show areas with high year-to-year variation in flow length, which indicate changes in local groundwater conditions and may provide early warning of ecological changes.Download file (1 MB)
Example wet/dry mapping instructions and data forms used for the San Pedro wet/dry mapping effort. For more information, see our wet/dry mapping page.
Includes 4 GIS datasets mapped to 1:100,000 scale stream-based hydrography for Arizona, including 1) the habitat for 33 native fish species, 2) former and current perennial surface flow for Arizona’s rivers, 3) the distribution of threatened and endangered species (ESA) that require aquatic or riparian habitats, and 4) Wild and Scenic River designations. Updated Dec 2010.
The Nature Conservancy commissioned a scientific literature review on impacts to aquatic organisms from exposure to municipal wastewater effluent. The review also covers the effectiveness and costs of available treatment technology for reducing exposure. The review was prepared by Dr. David Quanrud of the University of Arizona and Dr. Catherine Propper of Northern Arizona University. The executive summary provides an overview of the report’s major findings, including the best practices identified in the scientific literature for treating effluent.
Published in PLoS ONE, this study used four scenarios to explore the potential effects of alternative growth and water management strategies on river flows. Under the base population projection, we found that rivers in seven of the 18 study watersheds could be dewatered due to municipal demand. Our approach provides a low-cost method to identify where alternative water and growth management strategies may have the most impact, and demonstrates that such strategies can maintain a continued water supply for both people and the environment.Download file (1 MB)
This chapter, from Ecology and Conservation of the San Pedro River (edited by J. Stromberg and B. Tellman), provides an in-depth treatment of the collaborative effort of scientists, agency representatives, non-governmental organizations, elected officials, and other stakeholders and the role of adaptive management in addressing water policy and management issues in the Sierra Vista subwatershed of the upper San Pedro River.Download file (4 MB)
Series of 4 map exhibits illustrating conservation-related data on the status of this internationally-recognized desert river and riparian corridor. Maps include both the U.S. and Mexico portions of the San Pedro watershed depicting the following themes: Conservation Investments; Riparian Ecological Condition; Current and Formerly Perennial Stream Reaches; and a Water Budget.Download file (21 MB)
Presents a literature review and results of a May 2007 workshop where 35 subject experts from 16 agencies and institutions synthesized the state of knowledge for central Arizona’s Verde River. Report describes the river’s ecosystem, including its hydrology, geomorphology, riparian, and aquatic habitats, and fish and wildlife species – and how components would respond to changes in surface- and groundwater flows.
Presents information on the condition of riparian habitats and compares these with objectives established in BLM’s Resource Management Plan. Includes 1) an analysis of data collected between 1990 and 2006 on the condition of the NCA’s riparian forests and stream channel geomorphology, 2) an ecological state-and-transition model that describes relationships between habitat types and disturbance forces, and 3) a review of monitoring protocols with options for making monitoring more informative and efficient.
Download file (7.4 MB)
Describes the methods used to develop a GIS dataset for 33 native fish species in Arizona, presents results of some analyses using the data, and describes the data’s utility for the conservation of native fish. This is a preprint of an article published in Aquatic Conservation: Marine and Freshwater Ecosystems, Vol. 17: 737-748 (2007).Download file (< 1 MB)
This study analyzed 15 years of data on the endangered Gila topminnow (Poeciliopsis occidentalis occidentalis) to determine the population status and trend at Las Cienegas. We also tested alternative monitoring protocol to provide managers with more timely and reliable information on topminnow populations.Download file (1.5 MB)
Describes challenges for managing water resources in the Southwest, and recommends actions to improve ecologically sustainable water management. Published in May/June 2007 issue of Southwest Hydrology.Download file (1.3 MB)
Published in the July/August 2006 issue of Southwest Hydrology, this paper outlines the key building blocks for sustainable water management in the upper San Pedro River. It describes the role of the public–private consortium - the Upper San Pedro Partnership, the development of information and scientific tools to help answer key questions and identify tradeoffs in water management alternatives, and the importance of cooperation, collaboration and commitment of scientists, stakeholders and elected officials.Download file (1 MB)
Describes research indicating groundwater is moving through the floodplain alluvial aquifer at Three Links Farm, and that most of this water originates from the Upper San Pedro River Basin. Published in March/April 2005 issue of Southwest Hydrology.Download file (< 1 MB)
Describes The Nature Conservancy’s flow management approach to increasing water supply for riparian vegetation, based largely on results from hydrologic analyses indicating that retiring agricultural pumping at key locations increases water availability for riparian vegetation. Paper presented at USFS conference, May 11-15, 2004.Download file (< 1 MB)
Documents efforts by TNC and BLM to test a model that prescribed burns can be used to improve watershed conditions and aquatic habitat conditions. Study documents pre- and post-treatment results for the response of grasslands and for populations of the threatened Gila chub (Gila intermedia). Paper presented at USFS conference, May 11-15, 2004.Download file (<1 MB)
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