![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081107122833im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
2001 Progress Report: Restoring and Maintaining Riparian Ecosystem Integrity in Arid Watersheds: Meeting the Challenge through Science and Policy Analysis
EPA Grant Number: R827150Title: Restoring and Maintaining Riparian Ecosystem Integrity in Arid Watersheds: Meeting the Challenge through Science and Policy Analysis
Investigators: Maddock, Thomas , Baird, Kate , Baker, Victor R. , Colby, Bonnie G. , Glennon, Robert J. , Stromberg, Julie
Current Investigators: Maddock, Thomas , Baird, Kate , Baker, Victor R. , Breckenridge, Cabell , Colby, Bonnie G. , Glennon, Robert J. , Stromberg, Julie
Institution: University of Arizona , Arizona State University , University of Arizona
Current Institution: University of Arizona
EPA Project Officer: Stelz, Bill
Project Period: January 15, 1999 through January 1, 2002
Project Period Covered by this Report: January 15, 2001 through January 1, 2002
Project Amount: $849,638
RFA: Water and Watersheds (1998)
Research Category: Water and Watersheds
Description:
Objective:This research project brings together experts from a broad range of disciplines, hydrology, ecology, economics, and law, who are centrally involved in the restoration of riparian areas in the arid West. The objective is to further community-based environmental protection by integrating hydrologic models, a riparian ecosystem integrity index, and economic analysis into a user friendly decision support system (DSS), coupled with an analysis of the legal strengths and weaknesses of various management approaches. To this end, the project is actively clarifying the hydrologic, ecological, economic, and legal characteristics of two endangered arid watersheds: (1) the South Fork of the Kern River in California, and (2) the San Pedro River in Arizona. We aim to use this information to construct a comprehensive DSS.
In our research, we are pursuing a series of distinct but interrelated objectives. Based on extensive field studies, we are: (1) refining existing hydrologic models of riparian corridors to account for the complex interactions between variations in streamflow, evapotranspiration, and groundwater; (2) quantifying changes in the structure, function, and biotic integrity of the riparian community in response to these hydrologic interactions, as well as to anthropogenic influences; such as land use changes, streamflow diversions, and groundwater pumping; and (3) creating a riparian ecosystem integrity index based on landscape, community, and population level traits. This information will then be incorporated into a comprehensive hydrologic and ecological model to provide a framework for examining alternative land and river management practices, and assess potential risks to the biotic integrity of the riparian ecosystem from the anthropogenic manipulation of the hydrology and ecology systems.
Simultaneously, we are: (1) developing economic models to assess the cost of hydrologic and ecological management alternatives within the context of the local community; (2) evaluating the competency of institutional structure in water resource management; and (3) developing procedures that provide management institutions with scientifically and economically sound information on the current status of a resource, while improving their ability to predict the economic and ecological outcomes of management decisions. Combined with an analysis of legal constraints and opportunities relating to riparian management, these projects will be combined into an integrated model that can assist local governments and stakeholders in understanding the impact of development on a particular watershed, and in evaluating different strategies for achieving environmental restoration from a scientific, economic, and legal perspective.
Progress Summary:Hydrology research in 2001 saw extensive modeling and analysis of field data from the South Fork Kern River Basin, as well as hydrology experiments, modeling, and analysis in the Upper San Pedro Basin.
For the South Fork Kern Basin, the hydrology team correlated historic stream flow information to the ages of trees to determine if spring flows of 2,000 cfs (cubic feet per second) are necessary for successful tree recruitment. Extensive surveys of stream and land geometry throughout the valley, along with detailed studies of tree size, tree sap movement, and species density, were combined with irrigation and domestic water use information to provide data for a series of computer models of the valleys hydrology:
· The Army Corps of Engineers' Hydraulic Engineering Center's River Analysis System (HEC-RAS) used stream discharge measurements, taken at four locations over 3 years, to determine the extent of the active recruitment zone and to provide general analysis of surface water response.
· A geographic information system (GIS) model, using the ARC View program, was created to provide a conceptual model of the South Fork Kern Valley, including digitized representations of the river, agricultural lands, riparian areas, irrigation channels, and wells. Within the riparian area, the model represents species composition, density, cover, and diameter at breast height (DBH). Areas of similar tree densities were digitized and seasonal changes in evapotranspiration were calculated.
· A GIS-based hydrologic model, the Automated Geospatial Watershed Assessment, analyzes discrete portions of the watershed, based on soil information, to characterize flow planes within the valley.
· A kinematic runoff and erosion model uses this flow plane information to predict the levels of interception, infiltration, and surface runoff that are likely to result from a given precipitation event.
· All values are being imported into a groundwater modeling system (GMS) for groundwater simulations.
Together, the models above will allow comprehensive hydrological analysis of climate change and development scenarios.
In the San Pedro River Basin, the hydrology team designed and completed a pumping experiment to simulate aquifer draw-down produced by pumping in the basin. The experiment involved installation of five piezometers for water level monitoring, three pumping wells, and four access tubes for a borehole ground penetrating radar (BGPR). Two 72-hour pumping tests were performed, and the hydrology team has completed its analysis of the transmissivity and storage properties of the aquifer. Work is progressing on incorporating theses values into numerical modeling of the project area.
BGPR also was used to monitor the moisture content of soil above the saturated aquifer (the "vadose zone"). Analysis of this information revealed that drainage from the vadose zone continued even after pumping of the underlying aquifer was stopped. Direct comparisons of water storage change with drawdown measurements gave a measure of specific yield and demonstrated the effects of delayed drainage on the response of the unconfined aquifer. System flow was modeled using the HYDRUS-1D program, a finite element model for simulating the 1-dimensional movement of water in variably saturated media.
Through 2001, ecological research included completing field data collection along the San Pedro River. Data gathered from 18 sites reflect flow conditions (perennial to ephemeral stream flow), distance from the stream channel, information on diversity, structure, and composition of vegetation, as well as diversity, abundance, and composition of terrestrial anthropods.
In 2001, significant progress in statistical analysis addressed the following issues:
1. How Fremont cottonwood, Goodding willow, and saltcedar stand composition and structure vary across lateral floodplain gradients and along longitudinal gradients of ground water depth and surface flow permanency.
2. Identification of hydrologic thresholds above which the native cottonwood and willows maintain dominance over the exotic saltcedar.
3. Variations in total community structure across hydrologic gradients.
4. Identification of hydrologic thresholds for maintaining riparian forests in various ecological conditions.
5. How herbaceous species diversity, composition, and abundance vary across gradients of surface flow frequency and depth to groundwater.
6. Which herbaceous plant community bioindicators best and most consistently respond to ground and surface water decline.
Single-factor regression (linear and non-linear) and correlation analyses were used to determine relationships between site- and patch-level woody vegetation abundance (dependent variables) and hydrology (independent variables).
The ecology team also completed an up-to-date literature review of methods for assessment of riparian ecosystem health.
The economics team gathered economic data at study sites in southern Arizona and California during the last 12 months. This included extensive random sample visitor surveys at the Kern River Preserve and at selected riparian sites in the Upper San Pedro River Basin. Data analysis also was completed and summary reports on economic issues were prepared and sent to local stakeholders in both regions. The reports document visitor expenditures and economic values for riparian preservation.
Also, during the past year, a prototype model was developed to quantify the impacts of riparian habitat on private property values in desert cities, with preliminary results distributed to stakeholders.
Finally, policy instruments that potentially could be used to protect riparian habitat were identified and evaluated for their economic strengths and weaknesses.
The legal team identified strategies for preserving or restoring flows in the South Fork Kern and San Pedro Rivers, identified potential barriers to effective use of those strategies, analyzed recent legal developments in Arizona and California, and prepared an exhaustive analysis of the Colorado River Delta.
The legal team also analyzed the likely effectiveness of three purchase-oriented approaches to preserving flows: (1) acquiring key lands; (2) acquiring conservation concessions that would restrict the use of water on key lands; and (3) acquiring water rights on a temporary basis through leasing. While each of these approaches offers the promise of significant flow protection, effective implementation faces potentially serious barriers, including limited funds, local political opposition, and groundwater-surface water legal regimes that hold the potential to undercut the benefits of such purchases.
In addition, the legal team analyzed Arizona's law of groundwater-surface water interaction, as announced in the Arizona Supreme Court decisions on individual issues within the State's long-running general stream adjudication, "The General Adjudication of All Rights to Use Water in the Gila River System and Source." The decisions appear to create barriers to effective protection of groundwater flows that feed the San Pedro River, in that they only subject a narrow category of groundwater to regulation under Arizona's prior appropriation water rights system, which is primarily oriented toward surface water. A number of legal approaches hold the potential to protect the flows, however, either alone or in combination with the purchase strategies described above.
The legal team analyzed California's approach to the connection between groundwater and surface water rights, based on a research project conducted by Professor Joseph Sax. The analysis suggests that existing California law allows for the protection of instream flows against groundwater pumping through the mechanism of private litigation, even though the permitting jurisdiction of the State Water Resources Control Board is restricted through a bifurcated ground water-surface water system that resembles Arizona's approach.
Professor Robert Glennon and Law Student Peter Culp (JD 2001) prepared and published a lengthy paper on the Colorado River Delta. The terminus of the Colorado River in Mexico, the Delta has attracted considerable interest among environmentalists on both sides of the U.S.-Mexico border. The Glennon/Culp paper describes how recent flood events have brought back a tremendous number of acres of riparian vegetation that support endangered species in the Delta, and analyzes the allocation of legal rights to the Colorado River. The paper also describes recent developments that are placing considerable stress on this allocation regime. The paper suggests that it is in the interest of the Bush administration, through the State Department and the International Boundary and Water Commission, to act to save the Delta. Finally, the paper analyzes legal opportunities for securing water rights that would protect the Delta's environment.
Professor Robert Glennon has completed his manuscript Water Follies: Groundwater Pumping and the Fate of America's Fresh Waters. It will be published by Island Press in the fall of 2002. Chapter 4 analyzes the San Pedro River, "a river at risk" of drying up due to overpumping groundwater.
Future Activities:The hydrology team will import all its modeled values for the South Fork Kern River into a GMS for groundwater simulations. For the San Pedro River Basin, the team will incorporate values from its pumping test, as well as system flow modeling data into a numerical model for the San Pedro. These models then will be used to conduct a comprehensive hydrological analysis of climate change and development scenarios.
The major remaining task for the ecology team is integration of its statistical findings on the relationships between hydrology and specific biological indicators, as described above, into a comprehensive index of biological integrity, which will ultimately be integrated into the DSS described above.
The economics team will be write up results, refine analysis of data collected, prepare publications for academic outlets as well as for policy makers and the public, and present findings at professional conferences.
The law team will prepare a comprehensive overview of legal issues pertaining to efforts to protect the riparian ecosystems of the South Fork Kern and San Pedro Rivers, and will conduct legal analysis of policy options proposed to achieve hydrological, ecological, and economic goals proposed by the other teams.
Journal Articles on this Report: 2 Displayed | Download in RIS Format
| Other project views: | All 36 publications | 11 publications in selected types | All 6 journal articles |
| Type | Citation | ||
|---|---|---|---|
|
|
Colby BG. Resolving interjurisdictional disputes over water and environmental quality. Water Resources Update 2001;36(118):20-29. |
R827150 (2001) |
not available |
|
|
Glennon RJ, Culp PW. The last green lagoon: How and why the Bush Administration should save the Colorado River Delta. Ecology Law Quarterly 2002;28(4):903-992 |
R827150 (2001) |
not available |
water, watersheds, groundwater, ecosystem indicators, restoration, habitat, integrated assessment, decision making, survey, socioeconomic, compensation, conservation, environmental assets, social science, ecology, hydrology, economics, law, socioeconomic surveys. , Ecosystem Protection/Environmental Exposure & Risk, Economic, Social, & Behavioral Science Research Program, Water, Scientific Discipline, RFA, Ecosystem/Assessment/Indicators, Water & Watershed, Restoration, Aquatic Ecosystem Restoration, decision-making, Mercury, Economics & Decision Making, Hydrology, Watersheds, Ecology and Ecosystems, risk assessment, arid watersheds, ecosystem valuation, public policy, socioeconomics, watershed restoration, econometrics, community-based research, ecology assessment models, decision making, ecological recovery, riparian ecosystem integrity, conservation, GIS, aquatic ecosystems, integrated assessment, community involvement, riparian ecosytem integrity, restoration planning
Relevant Websites:
Progress and Final Reports:
1999 Progress Report
2000 Progress Report
Original Abstract
Final Report