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2000 Progress Report: Establishing Correlations Between Upland Forest Management Practices and the Economic Consequences of Stream Turbidity in Municipal Supply WatershedsEPA Grant Number: R825822
Title: Establishing Correlations Between Upland Forest Management Practices and the Economic Consequences of Stream Turbidity in Municipal Supply Watersheds
Investigators: Hulse, David , Grant, Gordon , Whitelaw, E.
Current Investigators: Hulse, David , Grant, Gordon , Niemi, Gerald J.
Institution: University of Oregon
EPA Project Officer: Clark, Matthew
Project Period: October 1, 1997 through September 30, 2000 (Extended to September 30, 2001)
Project Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $320,000
RFA: Decision-Making and Valuation for Environmental Policy (1997) RFA Text | Recipients Lists
Research Category: Economics and Decision Sciences
This research will: (1) prepare an analytical framework for estimating the downstream costs from increased sedimentation caused by land and reservoir management activities; (2) employ it to improve understanding of the sediment costs incurred by the city of Salem, Oregon, and its water users from such activities in the Santiam watershed; and (3) coordinate with stakeholders and other interest groups to identify and evaluate policy alternatives for managing these costs. Progress Summary:
The focus of this study consists of measuring the downstream costs of increased sedimentation and determining the extent to which sediment stems from land and reservoir management activities in the North Santiam watershed, a sub-basin within western Oregon's Willamette River basin. Three tasks are being undertaken separately by teams of researchers, identified as A (Hulse),B (Whitelaw), and C (Grant) below.
- Current data do not allow conclusive determinations regarding key project questions. To address this problem, the Hulse research team developed a geographically referenced database of natural and cultural factors relevant to project objectives. Among other uses, these have contributed to a multiagency/multidisciplinary team of professionals operating as the "North Santiam River Sediment Study Group." This group has implemented expanded monitoring efforts in the North Santiam watershed aimed at better understanding and managing detrimental effects of turbidity on municipal water supplies. The results from economic and geomorphic investigations of the research are being integrated with these geospatial data to formulate a synthetic understanding of the role of land and water management in producing turbidity and the tradeoffs to be confronted in minimizing turbidity in the future. There currently are no data to report on this task.
- During the past year, Whitelaw, et al., have concentrated on working with our collaborators from the University of Oregon and the Oregon State University's Forest Sciences Laboratory to develop a conceptual model summarizing the central lessons offered by the Salem-Santiam case study and explaining the interactions among a municipal water utility, land managers in the watershed providing surface water for the utility's use, and the operators of dams that affect the timing and quantity of water flows. At a meeting sponsored by the U.S. Department of Agriculture Forest Service's Pacific Northwest Research Station, regarding its Water Initiative, we discussed our findings about the impacts of the 1996-97 floods on the city of Salem's water utility and water customers, and the potential implications for the managers of national-forest lands in watersheds providing water to municipal utilities. We estimated the percentage of streamflows originating, by month, on national forest lands in the North Santiam sub-basin (and other sub-basins of the Willamette River basin). Our results are summarized in a working paper, "Estimating streamflow from national forests in the Willamette River basin, Oregon," by Ernie Niemi, Michelle Gall, Matt Sayre, and Ed Whitelaw. There currently are no data to report on this task.
- This past year's work has focused on finishing the field work, analysis, and writeup of the geomorphology section. The summer field season was directed at a stratified sampling of sediment from landforms distributed throughout the North Santiam watershed and resulted in acquisition of over 100 sediment samples. We also developed and tested a new technique for determining turbidity production from each landform. Sediment is resuspended in water and turbidity is measured over a 5-day period; the resulting time versus turbidity curve yields a systematic way of characterizing the persistent turbidity production from the sampled landform. We currently are analyzing the samples using this technique. At the same time, we are using X-ray diffraction techniques to identify the clay mineralogy of the individual samples. We will be able to directly link landforms with both turbidity potential and clay mineralogy. Because the landforms were sampled to represent distinctive sediment transport processes active in the basin (i.e., landslides, earthflows, fluvial deposition), this analysis will rigorously identify which processes are contributing turbidity-causing sediments to the North Santiam River. Using known relations between land management and process rates, we can link land management activities to turbidity production, which was the goal of this section of the project.
Results from this analysis are being written up as a Masters thesis for R. Ulrich, with a projected completion date of spring 2001. Two technical papers are planned from this thesis: (1) an examination of process/landform/turbidity relationships for the North Santiam River; and (2) a technique paper describing this new approach for assaying turbidity. We anticipate that both papers should be ready for submission by summer 2001. Development of the turbidity assay technique took longer than we anticipated, because it required careful experimentation to determine the temperature and concentration ranges necessary to get good results. Other than that, we have not encountered significant difficulties.
Preliminary Data Results: Data still are being analyzed, but we have families of turbidity versus time curves for our sediment samples that clearly demonstrate that those samples derived from smectite-rich clays have much slower settling times, hence higher turbidities than samples from nonsmectite clays. We expect that the clay mineralogy will further confirm these results.Future Activities:
In the time remaining in this study, Hulse, et al., will finalize the integration of the geospatial data and economic and geomorphic components of the project into a set of policy and land/water management recommendations for managing tradeoffs in municipal water supply watersheds using Salem, Oregon, as a case study. The project team has been meeting monthly since June 1999 to complete this synthesis.
Whitelaw, et al., will complete the final version of "The city of Salem and the North Santiam: the economic consequences of waterborne soil." We also will continue to meet with other researchers, particularly David Hulse and Gordon Grant, to coordinate the next phases of our research projects.
Grant, et al., will finish data analysis, writeup, and publication of results, including a group synthesis paper.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 11 publications||3 publications in selected types||All 2 journal articles|
|| Hulse D, Ribe R. Land conversion and the production of wealth. Ecological Applications 2000;10(3):679-682.
watersheds, sediments, Pacific northwest., RFA, Economic, Social, & Behavioral Science Research Program, Scientific Discipline, Geographic Area, Water, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Water & Watershed, Ecosystem/Assessment/Indicators, Ecosystem Protection, State, Forestry, Ecological Effects - Environmental Exposure & Risk, decision-making, Pacific Northwest, Drinking Water, Watersheds, Economics & Decision Making, ecosystem valuation, risk assessment, logging, ecological exposure, community involvement, Oregon, Willamette River Basin, forest ecosystems, human population growth, other - risk assessment, economic incentives, environmental values, flood management, municipal supply watershed, watershed land use, environmental policy, aquatic ecosystems, forests, public values, stream turbidity, water quality, upland forest management, public policy, municipal sopply watersheds, cost effectiveness, land use