Connecting the Environment to Arizona Water Planning

EnWaP

Looking Ahead

Upcoming Presentations:September 19th-20th:Arizona Hydrologic Society Annual Symposium, Phoenix, AZ

September 20th: Arizona Planning Association Meeting, Flagstaff, AZ

September 28th:Coconino Plateau Water Advisory Council, Flagstaff, AZ

Survey Coming Soon!The WRRC is exploring how the environment can be considered in water planning, and we will use this information to help stakeholders create a roadmap that articulates common water management objectives and strategies to meet those objectives. We will be looking for your involvement to develop the roadmap. As a first step, we will be asking you what drivers you think will determine the future of water in Arizona, and what criteria you would use to define water management priorities for the state. Look for a survey later this month where you can provide your opinion on these key components of the roadmap.

Project Newsletter / September 2012 / Issue 2The purpose of this newsletter is to keep the many interested partners of the EnWaP project informed about our activities and highlight relevant information about water and the environment. Future newsletters will be distributed quarterly.

Arizona’s Rivers Run Dry In July the Arizona Daily Star ran an article by Tony Davis focusing on the dire state of Arizona’s rivers due to ongoing drought. The article provided historical personal accounts indicating that many places where water used to run are now dry. This may seem alarming to some readers or like a natural variation in climate and hydrology. For the natural system, extreme events can be the tipping point across important thresholds, past which some (or all) components of the native ecosystem may not survive. While the shift to a new ecosystem dynamic may be part of a natural cycle, articles about drought and river impacts grab attention and raise difficult questions. Should, or can, water managers take action to preserve species of native fish, wildlife and plants through addressing ecosystem needs? What can be done to address environmental water demands without harming existing water users? In ad-dition, managers are increasingly considering whether human uses of water are putting these stressed ecosystems at risk, because of the social and economic values of Arizona’s environment. The EnWaP project is providing information to help Arizona’s water man-agers answer these questions.

Flows for Native SpeciesTo determine whether native river and riparian species are vulnerable, i.e. if ecosystem needs aren’t being met, we need to know something about the flows that maintain the environment. The scientific understanding is that there are a range of settings under which an ecosystem, or a species for that matter, can survive. When flow levels drift outside certain thresholds, ecosystems can lose functionality irrevocably. Sometimes humans don’t notice until the threshold is crossed and restoring the system can only be accomplished with significant investment, if at all.The survival of a given population or ecosystem over the long run depends on its capability to withstand extreme events, a trait called resilience. To complicate matters, ecosystem resilience often requires the full range of historical flow patterns be in place to maintain natural disturbance processes.

This project is working to provide information essential to considering the demands of the environment in discussions about water management. This article highlights a few

Interested in learning more about the desert rivers and riparian areas in your region?Contact the WRRC, and we will tailor a presentation based on your group’s interest in and questions about water demands of the environment in your region or across the state. Also, the WRRC is available to provide direct support for your water planning process by providing data, maps, and scenario analyses to help incorporate the environment.

Water Resources Research Center350 N. Campbell AveTucson, AZ 85721

Phone:520-621-9591

Fax: 520-792-8518

E-Mail:Kelly Lacroixklacroix@email.arizona.edu

Joanna Nadeaujnadeau@cals.arizona.edu

Please contact us for assistance!

Nina Mason Pulliam Trustwww.ninapulliamtrust.org

example maps and tables available to set management priorities for your area in addition to those described in the regional bulletins (see sidebar). Maps of surface water resources show where perennial streams, springs, and riparian areas occur around the state (figure at right). Information resources are also available to help answer questions about what level of flow is needed for species survival.

Trees that occur along riverbanks (riparian trees) provide shade and air purification as well as increase property values, and they use water available underground in the form of shallow groundwater or from floods that saturate the soil. Some plants need water within a few meters of the surface to establish, and its presence throughout the year is important for their survival. Similar native species occur in the riparian areas around the state, and these species have relatively consistent water depth limitations.

By comparing these limits for riparian species against current depths to shallow groundwater, water managers are better able to identify riparian areas in danger of degradation. Published minimum and maximum depths to groundwater for several native riparian species are listed here:

Flowing water is necessary in streams for aquatic species (like fish) to function or instream activities (like boating) to occur. Mr. Davis highlighted in his article that

loss of flows in perennial areas (like those indicated on the figure above) is occurring for the first time in many places across the state. Wet-dry monitoring, done annually by The Nature Conservancy and others, tracks where streams have surface flow and where they are dry (see 2012 wet-dry map for San Pedro River at left). For more information, see their website: azconservation.org. Loss of perennial surface flow in reaches that have consistently had water in the past can lead to alteration of aquatic and riparian communities and indicate changes in groundwater conditions. Annual monitoring provides a systematic dataset that can be used to identify these shifts in flow status by comparing changes over several years.

In some Arizona streams, researchers have defined the minimum flow needed in each

month of the year to maintain ecological values. Only five studies in Arizona have defined flow volumes needed for the riparian or aquatic ecosystem; tables and a summary of these findings are below. Where flow needs of a stream have been defined, monitoring of current flows can indicate whether prescribed needs are being met. When flows cross prescribed limits, managers have an indication that the system may be stressed and that they should be mindful of tipping points. We do not have a complete picture of minimum flow needs for the entire state.

Central Region: One study - by the U.S. Fish and Wildlife Service - describes the flows needed to maintain aquatic ecosystem function in the East Verde River (U.S. FWS, 1989). Notably, records from 2011 and early 2012 indicate that flows at the Childs gage currently fluctuate around the recommended minimum flow needs, sometimes dropping below it. Minimum instream flow needs (cfs) for the Verde River Reaches 1 through 5 are year-round minimum flows and for Reaches 6 through 10 are monthly minimum flows reflecting the natural hydrograph:

Southeastern Region: One study provides quantified recommendations for minimum daily flow volumes by month intended to support aquatic species and bottomland plants on Rincon Creek (NPS, 2008). The recommended flows should also support native mammals and birds.

North/Northeastern Region: One study, on the Colorado River, fully describes the flow volumes needed to maintain riparian ecosystem function. Based on flow experiments conducted in the Grand Canyon, high flows at the level of 77,700-88,300 cubic feet per second (cfs) lasting 3 or fewer days are recommended for regeneration of riparian vegetation (Kearsley and Ayers, 1999).

Colorado River Region: Two studies describe the flow volumes needed to maintain riparian and aquatic ecosystem function on the Bill Williams River (Hautzinger et al, 2006 and BWRC Technical Commitee, 1994). Hautzinger et al (2006) provides unified flood flow and baseflow prescriptions for the Bill Williams River, integrated from flow needs developed independently for aquatic, riparian bird and riparian non-bird species

Future demands can put some of these streams at risk, as demonstrated in a 2010 paper published in PLOS by The Nature Conservancy of Arizona (Marshall et al., 2010). The paper identifies Arizona watersheds where future municipal water demands will outpace and eventually exceed river base flows, shown in this summary graphic:

Rivers that are currently flowing all year round need flow to maintain current ecosystem function – but can we keep all of these rivers flowing? When drought reduces flows, options for augmenting flow in streams are few. When managers look at possible future scenarios before stressors collide, they may still have options for preserving Arizona’s river ecosystems and meeting human water demands.

References Cited:Kearsley, J. C., and T. J. Ayers. 1999. Riparian vegetation responses: snatching defeat from the jaws of victory, and vice versa. In The Controlled Flood in Grand Canyon, edited by R. H. Webb, J. C. Schmidt, G. R. Marzolf and R. A. Valdez. Washington, D.C.: American Geophysical Union.

Marshall, R. M., Robles, M. D., Majka, D. R., and J. A. Haney (2010) Sustainable Water Management in the Southwestern United States: Reality or Rhetoric? PLoS ONE 5(7): e11687. doi:10.1371/journal.pone.0011687

National Park Service. 2008. Assessment Report. Water-right Application No. 33-96733 for Instream-flow Maintenance. Middle Reach of Rincon Creek, Pima County, Arizona.

U.S. Fish and Wildlife Service. 1989. Fish and Wildlife Coordination Act Substantiating Report: Central Arizona Project Verde and East Verde River Water Diversions, Yavapai and Gila Counties, Arizona. Phoenix, Arizona: U.S. Fish and Wildlife Service Ecological Services.

Project UpdateIf priority environmental values are at risk, there are things that a community can do. A regional water plan can be developed to evaluate available strategies. Water managers can take action to minimize their impact on key ecosystem elements. An agency or organization can obtain a permit for instream flow rights to protect perennial flow from being diverted by new users in key reaches. Identifying the range of available strategies such as these, and the appropriate places to apply them, is the goal of this project.

Beginning in the Fall of 2012 and through 2013, the WRRC will lead an effort to engage individuals from diverse perspectives in developing a roadmap for considering the environment in Arizona’s water management, through statewide meetings and regional processes. The goal of this roadmap will be to articulate common water management objectives and explore strategies to meet those objectives. Ultimately, this collective effort will produce a roadmap document that describes “avenues” or categories of opportunities for considering the environment in water decision making, which can be pursued and refined at the local level in ways that meet the needs and reflect the priorities of existing water users.

Project OverviewThe University of Arizona Water Resources Research Center (WRRC) is in its second year of a three-year project, Connecting Environmental Water Needs to Arizona Water Planning (EnWaP). As part of this project we are talking to water stakeholders across Arizona about increasing water demands of our state and environmental water demands. Through dialogue among water users we endeavor to identify voluntary options for addressing the environment in the context of limited water supplies and existing water rights.

We are sharing information based on the WRRC’s recent compilation of information in the Arizona Environmental Water Needs Assessment

(AzEWNA), together with other statewide information on water demands. We are available to tailor this information to any area of the state to inform water planning.

wrrc.arizona.edu