VERDE VALLEY Files

2014-07-29 Verde Watershed Fly-thru Visualization

Come fly with us through the Verde River watershed! Under a new NSF Geosciences Education Program grant, we are developing a 3-D visualization of the Verde watershed. The watershed, located northeast of Phoenix, is the first focus area for a series of visualizations that are being developed as an educational tool for grade 8-12 classrooms. The goal of this tool is to educate students about basic hydrologic processes and important watershed concepts. The narrated fly-through will foster an understanding that goes beyond static maps and graphs. It features animated sequences and decision-making opportunities at various points in the upper and lower watersheds, making visible otherwise unseen processes, and creates a link for students to actually see the impacts of their own city on the changing watershed. Video available at: http://web.sahra.arizona.edu/education2/wsviz/

2014-07-30 River of the Month: The Verde River

Short profile of the Verde River. View Document.

2014-08-03 Ecological Implications of Verde River Flows - Summary

Summary report, 4 pages. The Verde River Ecological Flows study is a collaboration between The Nature Conservancy, Arizona Water Institute, and Verde River Basin Partnership. The purpose of the study is to develop a conceptual understanding of how the Verde River ecosystem would respond to variations in the river's hydrology—especially to decreases in river flows. The study team compiled and summarized what is known about the river's physical and ecological characteristics, drawing upon available data and what is known about hydrology-biology relationships on similar rivers. View Document.

2014-08-03 The History of SRP’s Claims on the Verde River and Current Legal Issues

Three part article written by Steve Ayers and published in the Verde Independent in 2003. Excellent summary. 5 pages. View Document.

A Cautionary Tale of Two Streamgages

An analysis of streamflow gage records shows that groundwater pumping in the Big Chino Valley and the Verde Valley will cause the Verde River to go dry for many summer days in the future. View Document.

Arizona Rivers Navigability Status

Summary report from American Whitewater: "The Arizona Navigable Stream Adjudication Commission ("ANSAC") has determined that, with the exception of the Colorado River, none of Arizona's watercourses is navigable. Ownership of the streambeds of non-navigable watercourses rests with either the federal government or private parties. Although the public likely enjoys recreational rights on waters above federally-owned streambeds, it has no such right to access waters above privately-owned streambeds." View Document.

Central Yavapai Highlands Water Resource Management Study

The Central Yavapai Highlands Water Resource Management Study (CYHWRMS) reports can be downloaded here.

Ecological Flows Assessment Presentation

Presentation by the Nature Conservancy to the Verde Watershed Association describing the Ecological Flows Assessment project. July, 2006 View Document.

Ecological Implications of Verde River Flows – Full Report

Full report, 124 pages. The Verde River Ecological Flows study is a collaboration between The Nature Conservancy, Arizona Water Institute, and Verde River Basin Partnership. The purpose of the study is to develop a conceptual understanding of how the Verde River ecosystem would respond to variations in the river's hydrology—especially to decreases in river flows. The study team compiled and summarized what is known about the river's physical and ecological characteristics, drawing upon available data and what is known about hydrology-biology relationships on similar rivers. View Document.

Enhancing the Understanding and Importance of Granting Instream Flow Water Rights in Arizona

Because of the rising demand for water supplies in urbanized, agricultural, and industrialized Arizona, water has been diverted from many rivers and streams to serve socio-economic needs. These diversions have often resulted in diminished stream flows and, when not properly managed, have had a negative impact on the riparian resources of Arizona's rivers and streams. To achieve a better economic and environmental balance in water allocations between instream and offstream uses, a more comprehensive understanding of the values of instream flows and the laws and regulations that affect allocations of these flows is needed. View Document.

Environmental Flows and Water Demands

This bulletin explains the water demands of the environment in the Central Arizona Region, an area that includes the Verde River, Agua Fria and Upper Hassayampa groundwater basins, as well as the Prescott Phoenix, and Pinal Active Management Areas (AMAs). Written by U of A WRRC. View Document. 

FAQ on the Northern Arizona Regional Groundwater Flow Model (NARGFM)

After securing project funding in 1999, the Arizona Department of Water Resources (ADWR) asked the USGS to develop a regional groundwater flow model for the north-central part of the State. In making this request, "the Department was fully aware of the capability of the USGS to develop an unbiased model that would improve understanding of the groundwater system and ultimately management of the region's water resources," according to Thomas G. Whitmer, ADWR's Manager of Statewide Water Planning. View Document.

Geologic Framework of Aquifer Units and Ground-Water Flowpaths, Verde River Headwaters, North-Central Arizona

Abstract: This study combines the results of geophysical, geologic, and geochemical investigations to provide a hydrogeologic framework of major aquifer units, identify ground-water flowpaths, and determine source(s) of base flow to the upper Verde River. This introductory chapter provides an overview of previous studies, predevelopment conditions, present surface-water and ground-water conditions, and a conceptual water budget of the hydrologic system. In subsequent chapters, this conceptual model will be evaluated and refined with respect to the results of each successive investigation. First, a compilation of mapping and field verification of the surficial geology, reinterpretation of driller’s logs, and contour mapping of alluvial thicknesses and buried volcanic rocks provide new three-dimensional geologic information. Second, a suite of geophysical techniques—including aeromagnetic and gravity surveys and inverse modeling approaches—was used to interpret the deeper subsurface geology. Third, geologic, geo- physical, and hydrological data were integrated to define basin boundaries, describe aquifer units in the basin-fill aquifers of Big and Little Chino valleys and the regional carbonate aquifer north of the upper Verde River, and develop a hydrogeologic framework. Water-level gradients were used to infer outlet flowpaths from the basin-fill aquifers through the carbonate aquifer toward the upper Verde River. Fourth, geochemical investigations employing analyses of dissolved major and trace elements and isotopes of δD, δ18O, 3H, 13C, and 14C were used to characterize major aquifers, identify recharge areas, and determine evolution of water chemistry along ground-water flowpaths. Fifth, results of a tracer-dilution study and synoptic sampling identify locations of major spring inflows discharging to the upper Verde River, measure base-flow contributions, which were used to calculate the relative contributions from each aquifer to upper Verde River springs using inverse geo- chemical modeling. In the final chapter, synthesis of multiple lines of evidence improve understanding of the relationships between the three aquifers, regional ground-water flowpaths, and the proportion of flow from each aquifer to the upper Verde River. Collectively, data from many varied and indepen-dent sources improves confidence in the conceptual model of the hydrogeologic system.

This file consists of 7 chapters and 246 pages totaling 135 mb. It can be downloaded here. 

Going with the Flow 2013

View Document.

Going with the Flow Update Final_04-23-2018

View Document.

Hydrogeology of the Upper and Middle Verde River Watersheds, Central Arizona

The upper and middle Verde River watersheds in central Arizona are primarily in Yavapai County, which in 1999 was determined to be the fastest growing rural county in the United States; by 2050 the population is projected to more than double its current size (132,000 in 2000). This study combines climatic, surface water, groundwater, water chemistry, and geologic data to describe the hydrogeologic systems within the upper and middle Verde River watersheds and to provide a conceptual understanding of the ground-water flow system. The study area includes the Big Chino and Little Chino subbasins in the upper Verde River watershed and the Verde Valley subbasin in the middle Verde River watershed. USGS report by Kyle Blasch. View Document.

Investigation of the Geology and Hydrology of the Upper and Middle Verde River Watershed of Central Arizona: Summary Report

In 1999, the U.S. Geological Survey (USGS), in cooperation with the Arizona Department of Water Resources (ADWR), initiated a regional investigation of the hydrogeology of the upper and middle Verde River watershed. The project is part of the Rural Watershed Initiative (RWI), a program established by the State of Arizona and managed by the ADWR that addresses water supply issues in rural areas while encouraging participation from stakeholder groups in affected communities. The USGS is performing similar RWI investigations on the Colorado Plateau to the north and in the Mogollon Highlands to the east of the Verde River study area (Parker and Flynn, 2000). The objectives of the RWI investigations are to develop: (1) a single database containing all hydrogeologic data available for the combined areas, (2) an understanding of the geologic units and structures in each area with a focus on how geology influences the storage and movement of ground water, (3) a conceptual model that describes where and how much water enters, flows through, and exits the hydrogeologic system, and (4) a numerical ground-water flow model that can be used to improve understanding of the hydrogeologic system and to test
test the effects of various scenarios of water-resources development. In 2001, Yavapai County became an additional cooperator in the upper and middle Verde River RWI investigation. View Document.

Middle Verde Paddle Guide

The Verde River Paddle Trail stretches 6.5 miles from the Tuzigoot Bridge to the Highway 89A Bridgeport Bridge. River access points are maintained by the Verde River Greenway-State Natural Area and Dead Horse Ranch State Park.
This guide is intended to help inform canoeists, kayakers and other river paddlers about what to expect along this portion of the Verde River. The guide is composed of four map segments along with a descriptive narrative. The river maps are oriented downstream from a paddler's point-of-view. A vicinity map shows how the segment maps provide coverage of each river reach. View Document.

Middle Verde Resource Analysis

Presentation slides describing VRBP project with USGS to better define water resources in the Verde Valley. View Document.

Policy Options for Water Management in the Verde Valley

The water of the Verde Valley, both in the ground and flowing at the surface, is a natural resource that is critical to the regional economy, environmental sustainability, and quality of life—but the Verde River faces unprecedented threats from over-allocation, development, and lack of cohesive water management. This report presents the results of three related initiatives designed to examine possible futures for the Verde and provides information for stakeholders and decision makers regarding the Verde Valley's water resources, its economic value, and possible tools for sustainable water management.
Our analysis included modeling the effects of growth on river flows and on the regional economy. Population growth and development in the basin, if not mitigated, are likely to cause further decrease in the summer base flow in the Verde River. Decreases in the Verde River's flow have already been observed, and further reductions could have harmful side effects on the region's economy and could lead to federal intervention in local water management to maintain habitat for endangered species. View Document.

Possible Effects of Groundwater Pumping on Surface Water in the Verde Valley, Arizona

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, has applied a groundwater model to simulate effects of groundwater pumping and artificial recharge on surface water in the Verde Valley sub-basin of Arizona. This is the summary of the full report. Results are in two sets of maps that show effects of locations of pumping or recharge on streamflow. These maps will help managers make decisions that will meet water needs and minimize environmental impacts. View Document.

Regional Groundwater-Flow Model of the Redwall-Muav, Coconino, and Alluvial Basin Aquifer Systems of Northern and Central Arizona (NARGFM)

Results of a major effort by USGS: a numerical flow model of the groundwater flow system in the primary aquifers in northern Arizona was developed to simulate interactions between the aquifers, perennial streams, and springs for predevelopment and transient conditions during 1910 through 2005. Simulated aquifers include the Redwall-Muav, Coconino, and basin-fill aquifers. Perennial stream reaches and springs that derive base flow from the aquifers were simulated, including the Colorado River, Little Colorado River, Salt River, Verde River, and perennial reaches of tributary streams. Simulated major springs include Blue Spring, Del Rio Springs, Havasu Springs, Verde River headwater springs, several springs that discharge adjacent to major Verde River tributaries, and many springs that discharge to the Colorado River. View Document.

Simulated Effects of Groundwater Pumping and Artificial Recharge on Surface-Water Resources and Riparian Vegetation in the Verde Valley Sub-Basin, Central Arizona

A USGS publication. In the Verde Valley sub-basin, groundwater use has increased in recent decades. Residents and stakeholders in the area have established several groups to help in planning for sustainability of water and other resources of the area. One of the issues of concern is the effect of groundwater pumping in the sub-basin on surface water and on groundwater- dependent riparian vegetation. The Northern Arizona Regional Groundwater-Flow Model by Pool and others is the most comprehensive and up-to-date tool available to under- stand the effects of groundwater pumping in the sub-basin. Using a procedure by Leake and others (2008), this model was modified and used to calculate effects of groundwater pumping on surface-water flow and evapotranspiration for areas in the sub-basin. This report presents results for the upper two model layers for pumping durations of 10 and 50 years. Results are in the form of maps that indicate the fraction of the well pumping rate that can be accounted for as the combined effect of reduced surface-water flow and evapotranspiration. In general, the highest and most rapid responses to pumping were computed to occur near surface-water features simulated in the modified model, but results are not uniform along these features. The results are intended to indicate general patterns of model-computed response over large areas. For site-specific projects, improved results may require detailed studies of the local hydrologic conditions and a refinement of the modified model in the area of interest. View Document.

Spatial and Seasonal Variability of Base Flow in the Verde Valley, Central Arizona, 2007 and 2011

Synoptic base-flow surveys were conducted on streams in the Verde Valley, central Arizona, in June 2007 and February 2011 by the U.S. Geological Survey (USGS), in coopera- tion with the Verde River Basin Partnership, the Town of Clarkdale, and Yavapai County. These surveys, also known as seepage runs, measured streamflow under base-flow condi- tions at many locations over a short period of time. Surveys were conducted on a segment of the Verde River that flows through the Verde Valley, between USGS streamflow-gaging stations 09504000 and 09506000, a distance of 51 river miles. Data from the surveys were used to investigate the domi- nant controls on Verde River base flow, spatial variability in gaining and losing reaches, and the effects that human altera- tions have on base flow in the surface-water system. The most prominent human alterations in the Verde Valley are dozens of surface-water diversions from streams, including gravity-fed ditch diversions along the Verde River.
Base flow that entered the Verde River from the tributary streams of Oak Creek, Beaver Creek, and West Clear Creek was found to be a major source of base flow in the Verde River. Groundwater discharge directly into the Verde River near these three confluences also was an important contributor of base flow to the Verde River, particularly near the conflu- ence with Beaver Creek. An examination of individual reaches of the Verde River in the Verde Valley found three reaches (largely unaffected by ditch diversions) exhibiting a similar pattern: a small net groundwater discharge in February 2011 (12 cubic feet per second or less) and a small net streamflow loss in June 2007 (11 cubic feet per second or less). Two reaches heavily affected by ditch diversions were difficult to interpret because of the large number of confounding human factors. Possible lower and upper bounds of net groundwater flux were calculated for all reaches, including those heavily affected by ditches. View Document.

State of the Verde River: Water Quality

The Sierra Club Water Sentinels have implemented a volunteer water quality and flow monitoring program on the Verde River. Teams of Water Sentinels volunteers have collected water samples, made field measurements of water quality parameters, and measured the flow of the river at six to eight sampling sites on the Verde River over the last five years. The data summarized in this report was collected between December 2, 2006, and December 10, 2011. The suite of water quality parameters include E. coli bacteria, total arsenic, total nitrogen, total phosphorus, and suspended sediment concentration. Water Sentinels also made field measurements of dissolved oxygen concentration, pH, electrical conductivity, total dissolved solids, and air and water temperature. They collected hundreds of water samples at six to eight sampling sites along the upper and middle reaches of the Verde River during all seasons in the five‐year period, visiting sampling sites on the Verde River five or six times each calendar year. View Document.

Sustainable Water Management in the Southwestern United States: Reality or Rhetoric?

While freshwater sustainability is generally defined as the provisioning of water for both people and the environment, in practice it is largely focused only on supplying water to furnish human population growth. Symptomatic of this is the state of Arizona, where rapid growth outside of the metropolitan Phoenix-Tucson corridor relies on the same groundwater that supplies year-round flow in rivers. Using Arizona as a case study, we present the first study in the southwestern United States that evaluates the potential impact of future population growth and water demand on streamflow depletion across multiple watersheds.
We modeled population growth and water demand through 2050 and 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. Implementing alternative growth and water management strategies, however, could prevent four of these rivers from being dewatered.
The window of opportunity to implement water management strategies is narrowing. Because impacts from groundwater extraction are cumulative and cannot be immediately reversed, proactive water management strategies should be implemented where groundwater will be used to support new 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.
Published by The Nature Conservancy. View Document.

The Battle to Save the Verde: How Arizona’s Water Law Could Destroy One of Its Las Free-Flowing Rivers

This Note explores a battle for water in the Southwest that may ultimately destroy one of Arizona's most precious rivers. This struggle pits the doctrine of reasonable use against the doctrine of prior appropriation and exposes the need to reconcile the uniquely Arizonan concept of "subflow," which purports to synthesize the laws of ground and surface water, with scientific reality. The characters in this complicated battle include rural municipalities that plan to pump from the river's headwaters, a major metropolitan utility company with century-old rights to the river, and an environmental advocacy organization seeking to protect endangered species. The plight of the Verde River exemplifies what has become a common tale in the United States—multiple parties with valid rights to the same water under different laws. Its resolution will likely require some difficult decisions about resource allocation, rural and urban growth, and the courts' willingness to side with science in the face of impossibly high stakes and a river in peril. By Merideth Marder, published in the Arizona Law Review. View Document.

The Verde river – A Desert Treasure at Risk

A 4 page informational brochure written by the Verde River Basin Partnership: "The Verde River is an irreplaceable treasure viewed as unique by people around the world. Unfortunately, the continued existence of its year-round flow and the life and lifestyles it supports are at risk." Published by the Verde River Basin Partnership. View Document.

USGS Publishes Verde Valley Seepage-Run Report

Substantially more water than necessary is diverted from the River during every growing season to support irrigation of farm fields, gardens, and lawns. Increased efficiency of the diversions and the irrigation they support will be essential to keeping more water in the river and protecting the Verde Valley's habitat and lifestyle. Published by the Verde River Basin Partnership. View Document.