Spatial and Temporal Variability of Clogging on Stream-Aquifer Interaction in the Upper Santa Cruz Valley

1 Title: Spatial and Temporal VariabillityVariability of Clogging on Stream-Aquifer Interaction in the Upper Santa Cruz Valley Project Summary In water-limited environments, effluent is an increasingly viable water source for riparian restoration and aquifer recharge Based on results from an existing TRIF supported project we have been able to document that effluent is an important component of the groundwater resources in the system, that clogging does occur and influence both surface and sub surface processes and that the impact of clogging varies over time In extending this previous research we seek to document the importance of effluent and clogging to the riparian vegetation of the system and gain some insight into the variability of clogging and effluents influence in time and space Our research will focus on the Upper Santa Cruz River where effluent aids in maintaining safe-yield conditions in the Santa Cruz AMA (SCAMA) In the current study we seek to determine influence of effluent quality on vegetation, use that influence to demonstrate the lateral extent of effluents influence on trees and estimate the temporal and spatial influence of clogging on recharge rates through the stream bed of the Santa Cruz We will so by addressing three questions First, how effectively are contaminants in the effluent transferred into tree tissue? Second, how does the influence of effluent on vegetation vary with distance from the river? Third, what is the spatial and temporal variability of streambed clogging and recharge within the Santa Cruz River? Duration: July 2008 – July 2009 Principle Investigators: Tom Meixner, Assoc Prof., Dept HWR, tmeixner@hwr.arizona.edu 520.626.1532 Paul Sheppard, Assoc Prof Tree-Ring Laboratory, sheppard@ltrr.arizona.edu 520.621.6474 TRIF Funds Requested: Leverage (matching) funds pledged: State of critical regional or state water problems: In arid and semi-arid regions, effluent has great potential as an additional water source that can support riparian vegetation, augment aquifer recharge, and sustain perennial surface flow in otherwise ephemeral streams Additionally the chemical composition of effluent can have an impact on the health of ecosystems and humans through acute and chronic toxicity effects, alterations of ecosystems processes and through biologically induced clogging which can alter Statement of Results or Benefits Through the proposed research, we hope to document the processes and patterns that influence the effects that effluent dominated rivers can have on their surrounding ecosystems We will so in a way that will provide knowledge of how both the quantity and quality aspects of effluent affect ecosystem processes Our study will document the influence of the space and time variability of clogging on recharge rates and thus water sustainability and water resource availability in the Santa Cruz AMA Additionally the information we gain on the influence of effluent quality on the chemical composition of tree rings will indicate how effluent moves through ecosystems and the spatial and temporal extent of its influence on drinking water sources as well as the sources of water preserving the ecosystems of the Santa Cruz valley Furthermore, given the knowledge gaps that exist in understanding the functioning of effluent-dominated streams, this research will provide the foundation for a larger interdisciplinary research initiative addressing the dynamics of riparian ecohydrology Part II Nature, Scope, and Objectives of the Research Effluent dominated rivers are a critical and growing resource in the desert southwest of the United States (ref) In fact in Arizona, Phoenix, Tucson and Nogales/Santa Cruz County all have significant wet river reaches that are dominated by effluent (ref) Often these effluent river reaches are critical ecosystem resources for wildlife and humans and thus are increasingly utilized to provide certain biodiversity and aesthetic ecosystem services to society Additionally effluent dependant rivers also recharge local and regional groundwater systems (ref) For these reasons it is critical to understand the biological and hydrological processes occurring in effluent dependant dependent rivers and how that might influence aquifer recharge and stream ecosystem biota The Water Sustainability program funded a TRIF proposal in the 2007-2008cycle that supported a project directed by Tom Meixner on “Stream Aquifer Interactions in Effluent Dominated Riparian Systems” This research has produced useful knowledge about the Upper Santa Cruz River that the project focused on First, the project identified that indeed effluent is far and away the dominant source of water to the river itself and is an important recharge source in the nearstream zone Second the project demonstrated that a clogging layer does develop in the stream bed of the Santa Cruz and, that this clogging varies in space with distance downstream of the Nogales International Wastewater Treatment Plant (NIWTP), and that this clogging seems to be removed or at least relieved following flooding Third, dendrochronology work shows that the effluent began having an influence on tree growth starting in the early 1970’s and that this influence continues to this day For more details on this project and these preliminary results please see an attachment at the end of this proposal summarizing our results thus far The current proposal is not a renewal of this current project but rather an extension beyond the original aims of that project In parallel to the documentation of effluent’s importance and the affect effect of clogging on the Santa Cruz, preliminary work to investigate the use of trees to identify the influence of effluent in the Santa Cruz system has been completed (Paul Sheppard unpublished data) Since, riparian trees have been shown to take up and remove certain nutrients, pollutants, and natural elements from surface and subsurface water (Marler et al 2001), this preliminary work has sought to identify potential effluent markers that could be used in tree rings The aim of the work is thus to enable the coupled use of dendrochronology (tree-ring science), and specifically dendrochemistry (chemical analysis of tree rings), as a tool for monitoring spatial and temporal changes in surface and groundwater quality along effluent-dependent waterways The pPreliminary data shows elevated levels of both europium (Eu) and gadollinium (Gd) in tree rings of cottonwood trees of the Upper Santa Cruz The Gd elevation is expected and a likely indicator of effluent influence since because Gd is used in medical magnetic resonance imaging and is a micropollutant that enters waterways from wastewater treatment plants (Bau et al 2006) The Eu spike is less expected but and indicates a need to develop a transfer function relating river and groundwater conditions to what is observed in tree rings Our preliminary results show elevated levels of Gd in the Upper and Lower Santa Cruz River, thus indicating good potential for developing dendrochemistry to detect the presence and temporal and spatial distribution of micropollutants in effluent-dependent waterways of Arizona A preliminary chemical analysis of two increment core samples from cottonwood trees found along the Upper and Lower Santa Cruz River revealed that the element europium (Eu) is noticeably elevated relative to natural abundance compared to other REEs (Figure 1A & C) This Conc entration/Natural A bundanc e 1.20 A: Tucson tree 1.00 1.00 0.80 0.80 0.60 0.60 0.40 0.40 0.20 0.20 0.00 0.00 La Ce Pr 0.25 C: Nogales tree 1.20 Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu La Ce Pr B: Tucson tree, w ithout europium D: Nogales tree, w ithout europium 0.25 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0.05 0.00 Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 0.00 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Rare Earth Element Figure Concentrations of REEs in two trees growing along the Santa Cruz River Eu signal is unexpected, and we are not sure what it means; learning more about environmental Eu will be a secondary objective of this research Notwithstanding Eu, Gd is noticeably elevated relative to natural abundance compared to the remaining REEs (Figure 1B & D) Furthermore, both trees indicate biannual variation in Gd as well as in the other REEs (Figure 2A & B) These Gd results confirm that this proposed project is likely to succeed in using trees to document Gd, and potentially other micropollutants, in effluent-dependent waterways The project outlined in this proposal will therefore expand data collection to effluent-dependent waterways throughout Arizona and will focus on sample analysis to quantify the presence, abundance, and temporal and spatial distribution of Gd in riparian trees Concentration/ Natural A bundance A; Tucson tree Gd only B: Nogales Tree Median w ithout Gd and Eu 0.40 0.50 0.30 0.40 Gd only Median w ithout Gd and Eu 0.30 0.20 0.20 0.10 0.10 0.00 1998 2000 2002 2004 2006 2008 0.00 1985 1990 1995 2000 2005 Year Figure Temporal patterns of Gd and other REEs in two riparian trees Coupled together, the existing upper Santa Cruz results and the dendrochemistry work point in an new and innovative research direction If we can demonstrate a link between the tree ring chemistry and effluent conditions, it should be possible for us to back out how the influence of effluent varies in space and has varied in time along the Upper Santa Cruz Additionally, we need to understand how clogging evolves temporally and spatially at a more detailed level to understand how river and effluent conditions influence aquifer recharge Our proposed research thus focuses on three questions- : First, how effectively are contaminants in the effluent transferred into tree tissue? Second, how does the influence of effluent on vegetation vary with distance from the river? Third, what is the spatial and temporal variability in streambed clogging and recharge within the Santa Cruz River? Approach, Methods, Procedures, and Facilities Answering these questions requires three research approaches First, we need to continue to quantify river and groundwater quality and to quantify rare earth elements in the surface and groundwaters of this system Second, we need to focus on several transects of trees to understand how river, vegetation, and groundwater conditions along with distance from the river Finally, we will need to investigate the spatial and temporally variability of the clogging layer in more detail than we have done to date This research will focus on three river reaches of the Santa Cruz AMA (Figure 2) O, one reach will be in the non-effluent dominated reach upstream from the NIWTP at Kino Springs The other two reaches will be in the effluent dominated reach of the river O; one at Rio Rico road just 3km downstream of the outfall and the other at Santa Getrudis Lane some 15km downstream from the outfall The reason for the selection of these two reaches is that our existing geochemical results in surface and groundwater indicate that the Rio Rico reach is losing while the Santa Getrudis site is gaining Additionally through the National Park Service we have access at Santa Getrudis Lane, at Kino springs we have the cooperation of the landowner, and at Rio Rico we are confident through cooperation with the Santa Cruz AMA we can gain access to the site Additionally there are groundwater wells that we have already sampled in cooperation with either the Arizona Department of Water Resources and with the National Park Service at each of these sites At each reach, surface water samples will be collected monthly for the duration of this project and be analyzed for major ions as well as rare earth element concentrations Similarly, at the wells in and near these river Figure Map of Santa Cruz AMA Black circles indicate approximate sampling sites Here study sites are at Kino Springs, Rio Rico Road and at the Tumacacori Mission reaches will be analyzed for rare earth elements to assess the background concentrations as well as the potential influence of effluent Once forested effluent-dependent reaches of streams have been identified, increment core samples will be taken from suitable, mature and healthy riparian trees (Populus fremontii and Celtis reticulata) growing therein The tree-ring samples will be crossdated and measured for REEs, with a focus on Gd Samples will be measured using inductively coupled plasma, mass spectroscopy (ICP-MS) at UA Soil, Water, and Environmental Sciences, who are experienced in ICP-MS and have worked with Dr Sheppard on previous dendrochemical analysis This research augments previous work conducted by doctoral candidate Amy McCoy (UA Arid Lands Resource Sciences) on riparian dynamics and will constitute a chapter of her dissertation This research will also contribute to Dr Sheppard’s on-going dendrochemistry research and innovation Furthermore, we will work with Friends of the Santa Cruz River and Arizona Department of Environmental Quality to obtain long-term records of water quality monitoring data along selected stream reaches Geophysical approach - ERT and temperature Related Research In many de-watered rivers in the western United States, discharges of effluent, or treated wastewater, can augment surface flow in ephemeral or intermittent streams and enhance riparian habitat (Tellman 1992, Marler et al 2001, Bouwer 2002, Brooks et al 2006) In addition to providing additional water to riparian systems, effluent is also high in nutrients and supplies additional nitrogen to the river system (Stromberg et al 1993) This additional water source may expand in the future as more groundwater is pumped to support growing populations and is available for re-use in habitat restoration projects and for aquifer reclamation Ultimately, these effluent flows may be critical to riparian survival in arid and semi-arid river systems where surface water and groundwater have been de-coupled due to anthropogenic changes and drought impacts (Patten et al 1998) Riparian ecosystems have been shown to be effective nutrient sinks that can rapidly remove nitrogen (N) and other nutrients from water flowing through floodplain soils, particularly in agricultural and effluent-dominated systems (Schade et al 2002) Nitrogen enters most natural riparian systems through importation of silt-laden floodwaters, surface runoff, and groundwater recharge from the surrounding watershed (Adair et al 2004) Effluent-dominated streams receive additional infusions of nutrients through daily inflows of nutrient-rich effluent However, the role of riparian vegetation in nutrient removal mechanisms remains unclear and patterns of nutrient accumulation and turnover are also poorly understood (Schade et al 2002, Adair et al 2004) For riparian vegetation specifically, Marler et al (2001) demonstrated in a controlled environment that Fremont cottonwood (Populus fremontii), Goodding willow (Salix gooddingii), and exotic saltcedar (Tamarix ramosissima) increased their shoot:root biomass ratio as nitrogen increased In a field experiment, Adair and Binkley (2002) demonstrated that cottonwood germinants were co-limited by both water and nitrogen, indicating that nitrogen may play an important role in riparian vegetation productivity and composition Therefore, additional inflows of nutrients into riparian systems may impact the rate of nutrient cycling as well as phreatophytic growth and abundance One yet unanswered question in riparian ecology is the degree to which riparian trees uptake other elements and pollutants, in addition to nutrients, found in effluent-dominated stream ways Recent research on emerging contaminants indicates that the presence of endocrine disruptors and other micro-pollutants in effluent-dominated streams impacts fish and macro-invertebrate populations (La Point and Waller 2000) While numerous methodologies can be used to detect the presence of emerging contaminants, dendrochronology can offer valuable insights into not only the presence or absence of certain elements, but can help decipher temporal patterns and variations as well In additional, there are many additionalother unresolved ecohydrological issues regarding the release of effluent, a third source of water, into ground-water dependent riparian systems Few if any studies have studied how native riparian vegetation responds to continued inflows of nutrient-rich effluent and the possible associated changes in riparian community composition and structure No studies have examined this from the perspective of climate variability and the potential for prolonged droughts and rising temperatures to increase freshwater demands, further degrade riparian systems, and potentially increase the number of streams reliant upon effluent to maintain surface flows and associated riparian habitats Ultimately, a lack of understanding about the dynamics of effluent-dominated streams has created a void in methods suitable for evaluating the ecological integrity of these systems (Brooks et al 2006) The research outlined in this proposal aims to fill a methodology void by pioneering the use of dendrochronology in detecting and documenting changes in groundwater quality in effluent-dominated streams in Arizona Training Potential In collaboration with PI, Dr Paul Sheppard, this research will be conducted between March 2008 – December 2008 by Amy McCoy, a doctoral candidate in Arid Lands Resource Sciences Additional opportunities for graduate student training include a collaboration with Meg White, a PhD candidate in Julie Stromberg’s laboratory at Arizona State University in the School of Life Sciences Information Transfer Participatory, bi-directional knowledge transfer will be critical to the success of this project Using local knowledge to help inform research efforts, the results of this multi-disciplinary project will have the potential to influence local decision making and provide the foundation for policy development The results of this research will need to be disseminated widely and will be of interest and utility to a great number of stakeholders, many of whom have already expressed an interest in the project, including Santa Cruz County, Arizona Department of Water Resources, SCAMA, Pima County, Friends of the Santa Cruz River, Sonoran Institute, Tumacácori National Historical Park, The University of Arizona (SAHRA, WRRC, Office of Arid Land Studies), and landowners along the Santa Cruz River Individual meetings with landowners will be scheduled, to ensure that they are kept up-to-date on the research being done on their land In addition, longer-term impacts will be derived from educational materials developed from this case study to support public education initiatives including the Riparian Ecology Extension Program, the Geospatial Extension Program, and the Master Watershed Stewards Program As an inherently inter-disciplinary project, the research results will be submitted for publication in several thematic journals In addition, the graduate students will present the results at one or more technical conferences An executive summary of the results will be made available via the websites of: the Laboratory of Tree-Ring Research (www.ltrr.arizona.edu), SAHRA (sahra.arizona.edu), the Office of Arid Land Studies (www.arid.arizona.edu), and the Friends of the Santa Cruz River (friendsofsantacruzriver.org) Tree-ring data developed for the project will be made available to the paleoclimatic research community through the World Data Center of the National Climatic Data Center (www.ncdc.noaa.gov/paleo) Section Interaction with Centers If funded, this project will be hosted and supported by SAHRA (see attached letter) Critically, our work on the Upper Santa Cruz seeks to extend the impact of SAHRA’s work on the San Pedro and Rio Grande to another setting Importantly, the question of water sustainability in the Upper Santa Cruz River Valley and the activities of this proposal align closely with SAHRA’s mission “to promote sustainable management of water resources by conducting water resourcesrelated science, education and knowledge transfer in the context of critical water management issues of semiarid and arid regions” One of SAHRA’s three main research questions involves the hydrologic context for river restoration; this is a research question in which James Hogan and Tom Meixner are involved Given the likely importance of effluent dominated rivers for efforts to increase the robustness of riparian areas in Arizona this study will fill an important gap in SAHRA’s mission Partnerships Friends of the Santa Cruz- This group provides a solid contact to the interested public in the study area, and facilitates contacting of individuals, landowners and others for permission to access sampling sites Potential Partnerships to Discuss – would these groups be interested in this research and can we get a letter of support: USGS Santa Cruz AMA Tucson AMA ADWR Local Landowners National Park Service Pima County Flood Others? Citations Adair, E C., and D Binkley 2002 Co-limitation of first year fremont cottonwood seedlings by nitrogen and water Wetlands 22:425-429 Adair, E C., D Binkley, and D C Andersen 2004 Patterns of nitrogen accumulation and cycling in riparian floodplain ecosystems along the Green and Yampa rivers Oecologia 139:108-116 Bau, M., A Knappeb, and P Dulsk 2006 Anthropogenic gadolinium as a micropollutant in river waters in Pennsylvania and in Lake Erie, northeastern United States Chemie der Erde 6:143–152 Bouwer, H 2002 Integrated water management for the 21st century: Problems and solutions Journal of Irrigation and Drainage Engineering-Asce 128:193-202 Brooks, B W., T M Riley, and R D Taylor 2006 Water quality of effluent-dominated ecosystems: ecotoxicological, hydrological, and management considerations Hydrobiologia 556:365-379 Colby, B G., D A de Kok, G Woodward, R P Maguire, S B Megdal, K L Jacobs, and M A Worden 2004 Arizona's Water Future: Challenges and Opportunities Tucson, Arizona Marler, R J., J C Stromberg, and D T Patten 2001 Growth response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima seedlings under different nitrogen and phosphorus concentrations Journal of Arid Environments 49:133-146 Patten, D T., R J Marler, and J C Stromberg 1998 Assessment of the role of effluent-dominated rivers in supporting riparian functions Arizona Water Protection Fund Final Report #95-010WP, Arizona State University, Tempe, Arizona Schade, J D., E Marti, J R Welter, S G Fisher, and N B Grimm 2002 Sources of nitrogen to the riparian zone of a desert stream: Implications for riparian vegetation and nitrogen retention Ecosystems 5:68-79 Stromberg, J., M R Sommerfeld, D T Patten, J Fry, C Kramer, F Amalfi, and C Christian 1993 Release of effluent into the Upper Santa Cruz River, Southern Arizona: Ecological considerations Pages 81-92 in M G Wallace, editor Proceedings of the Symposium on Effluent Use Management American Water Resources Association, Tucson, Arizona Tellman, B 1992 Arizona's effluent dominated riparian areas: issues and opportunities University of Arizona Water Resources Research Center Issue Paper 12, Tucson, AZ Tibbets, T M., and M C Molles 2005 C:N:P Stoichiometry of Dominant Riparian Trees and Arthropods Along the Middle Rio Grande Freshwater Biology 50:1882-1894 Investigator’s Qualifications – please see attached resume Laboratory of Tree-Ring Research University of Arizona Tucson, AZ 85721 PAUL R SHEPPARD office: (520) 621-6474 fax: (520) 621-8229 sheppard@ltrr.arizona.edu EDUCATION Ph.D (1995) The Univ of Arizona, Geosciences; major: Paleoenvironmental-Quaternary Studies with an emphasis in Dendrochronology; minor: Soil and Water Sciences M.S (1984) Cornell Univ., Natural Resources; major: Forest Science; minor: Statistics B.S (1982) Humboldt State Univ., CA, Forestry Resources Management (magna cum laude) A.S (1980) Long Beach City College, CA, lower division general science EMPLOYMENT Associate Professor, Lab of Tree-Ring Res., Univ of Arizona (since Aug 2007) Conducting research, teaching, advising, and extension activities in dendrochronology Assistant Professor, Lab of Tree-Ring Res., Univ of Arizona (Aug 2001 to July 2007) Conducted research, teaching, advising, and extension activities in dendrochronology Research Specialist and Adjunct Professor, Lab of Tree-Ring Res., Univ of Arizona (Sep 1997 to Aug 2001) Developed web-based teaching modules for dendrochronology, continuing general environmental research using dendrochronology, and teaching NSF-NATO Postdoctoral Fellow, Dept d'Ecologia, Univ de Barcelona, España (Sep 1996 to Aug 1997) With Dr Emilia Gutiérrez, researched effects of soil microsite conditions on tree growth, and collaborating with other dendrochronologists of NATO-member countries Visiting Assistant Professor, Lab of Tree-Ring Res., Univ of Arizona (Sep 1995 to Aug 1996) Taught Introduction Survey, Advanced Workshop, and Graduate Seminar courses in Dendrochronology, advised students, and researched environmental science projects Graduate Research and Teaching Associate, Lab of Tree-Ring Res., Univ of Arizona (Jan 1989 to Aug 1995) Assisted Dr Lisa Graumlich on tree-ring research from the upper-Midwest, Sierra Nevada, northwestern Alaska, and China Assisted Global Change course Senior Research Assistant, Tree-Ring Lab., Lamont-Doherty Geological Observatory, Columbia Univ (Sept 1984 to Dec 1988) Assisted tree-ring projects in forest ecology, dendroclimatology, and dendroseismology LANGUAGE SKILLS He obtenido el Diploma Básico de Español Como Lengua Extranjera, dado por el Instituto Cervantes de Salamanca de España, que indica que comunico adecuadamente sobre temas normales de la vida cotidiana AFFILIATIONS Society of American Foresters, since 1980 Soil Science Society of America, since 1994 American Quaternary Association, since 1994 Tree-Ring Society, since 2001 RECENT HONORS University of Arizona College of Science Distinguished Early Career Teaching Award (2005) University of Arizona College of Science Staff Recognition Award of Excellence (2000) PAUL R SHEPPARD RELEVANT PUBLICATIONS Sheppard, P.R and E.R Cook 1988 Scientific value of trees in old-growth natural areas Natural Areas Journal 8(1):7–12 Sheppard, P.R and T.L Thompson 2000 Effect of extraction pretreatment on temporal variation of nitrogen in tree rings Journal of Environmental Quality 29:2037–2042 Sheppard, P.R., P Casals, and E Gutiérrez 2001 Relationships between ring-width trends and soil nutrient availability at the tree scale Tree-Ring Research 57:105–113 Sheppard, P.R., A.C Comrie, K Angersbach, G.D Packin, and M.K Hughes 2002 The climate of the US Southwest Climate Research 21(3):239–258 Sheppard P.R and M.L Witten 2005 Laser trimming tree-ring cores for dendrochemistry of metals Tree-Ring Research 61(2):87–92 Sheppard P.R., G Ridenour, R.J Speakman, and M.L Witten 2006 Elevated tungsten and cobalt in airborne particulates in Fallon, Nevada: possible implications for the childhood leukemia cluster Applied Geochemistry 21:152–165 Sheppard, P.R., R.J Speakman, G Ridenour, and M.L Witten 2007 Using lichen chemistry to assess airborne tungsten and cobalt in Fallon, Nevada Environmental Monitoring and Assessment, 130:511–518 Sheppard, P.R., Speakman, R.J., Farris, C., Witten, M.L 2007 Multiple environmental monitoring techniques for assessing spatial patterns of airborne metals Environmental Science & Technology 41(2):406–410 Sheppard, P.R., R.J Speakman, G Ridenour, and M.L Witten 2007 Temporal variability of tungsten and cobalt in Fallon, Nevada Environmental Health Perspectives 115:715–719 Sheppard, P.R., R.J Speakman, G Ridenour, M.D Glascock, C Farris, M.L Witten 2007 Spatial patterns of tungsten and cobalt in surface dust of Fallon, Nevada Environmental Geochemistry and Health, DOI: 10.1007/s10653-007-9085-1 29:405-412 Sheppard, P.R., Ort, M.H., Anderson, K.C., Elson, M.D., Vázquez-Selem, L., Clemens, A.W., Little, N.C., and Speakman, R.J In review Multiple dendrochronological signals indicate the eruption of Parícutin Volcano, Michoacán, Mexico Journal of Volcanology and Geothermal Tree-Ring Research Sheppard, P.R., Hallman, C.L., Towner, R.H In review Environmental history of the Southwest as general science education Journal of Geoscience Education Sheppard, P.R., Ort M.H., Anderson, K.C., Clynne, M.A., May, E.M In review Multiple dendrochronological responses to the eruption of Cinder Cone, Lassen Volcanic National Park, California Dendrochronologia  ... rather an extension beyond the original aims of that project In parallel to the documentation of effluent’s importance and the affect effect of clogging on the Santa Cruz, preliminary work to investigate... understand how river, vegetation, and groundwater conditions along with distance from the river Finally, we will need to investigate the spatial and temporally variability of the clogging layer in. .. impact of SAHRA’s work on the San Pedro and Rio Grande to another setting Importantly, the question of water sustainability in the Upper Santa Cruz River Valley and the activities of this proposal