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The San Francisco Estuary and its upstream watershed have been highly altered by human development following the California Gold Rush in the mid-19th century. In this paper, we explore the inter- and intra-annual variability of freshwater flow to this estuary and the resulting salt intrusion under scenarios that represent pre-development and contemporary conditions. To place this comparison in context with the advent of systematic and accurate flow and salinity measurements in the estuary, we consider an additional “pre-project” scenario that represents early 20th-century water management (circa 1920), after major flood control and reclamation but before the introduction of large water storage, diversion, and export operations. We use an observed climate record that spans 82 years to compare freshwater flow associated with the scenarios’ landscape and water use characteristics. Using published relationships between flow and salt intrusion length developed from three-dimensional hydrodynamic modeling, we evaluate the effect of these flow alterations as well as estuarine geometry modifications and historically-observed sea-level rise on salt intrusion. We conclude that the pre-development estuary exhibited a more seasonally-variable salinity regime, resulting from a more variable inflow regime from the upstream watershed.

Provides personal narratives of four teachers regarding their work to create more democratic classrooms in urban settings. Explores the issues of authority and democracy in day-to-day teaching in the areas of (1) authority, democracy, and relationships; (2) formations; (3) authority and democracy in the writing workshop; and (4) reformations. (NH)

The California State Department of Water Resources and the United States Bureau of Reclamation Mid-Pacific Region have developed a general-purpose reservoir-river basin simulation model for the planning and management of the State Water Project and the federal Central Valley Project. The California Water Resources Simulation Model brings a fundamental change to modeling of these systems. Model users specify system objectives as input to the model. System description and operational constraints are specified using a new water resources engineering simulation language. A mixed integer linear programming solver efficiently routes water through the system network given the user-defined priorities or weights. Simulation cycles at different temporal scales allow for successive layering of constraints. The power and flexibility of the model is demonstrated by its ability to simulate the operation of complex new environmental water accounts. CE Database subject headings: Reservoirs; River basins; California; State government; Simulation models; Water resources management.

This paper presents results of a large-scale economic-engineering optimization model of California's water supply system. The results of this 4-year effort illustrate the value of optimization modeling for providing integrated information needed to manage a complex multipurpose water system. This information includes economic benefits of flexible operations, economic valuation of capacity expansion opportunities, estimating user willingness to pay for additional water, economic opportunity costs of environmental flows, and identification of promising conjunctive use and water transfer opportunities. The limitations of such modeling also are discussed. Overall, the results suggest improvements to system operation and water allocations with a statewide expected value potentially as high as $1.3 billion/year. Significant improvements in performance appear possible through water transfers and exchanges, conjunctive use, and various operational changes to increase flexibility. These changes also greatly reduce costs to agricultural and urban users of accommodating environmental requirements. Model results also suggest benefits for expanding selected conveyance and storage facilities. CE Database subject headings: Optimization; California; Water supply; Water shortage.

Properties of optimal hedging for water supply releases from reservoirs are developed and discussed. The fundamental decision of how much water to release for beneficial use and retain for potential future use is examined analytically. Explicit correspondence is established between optimal hedging and the value of carryover storage. This more analytical view of hedging rules is useful for better understanding optimal hedging and simplifying numerical optimization of hedging operating rules. The derivations suggest the frequent optimality or near-optimality of two-point hedging policies for water supply operations. CE Database subject headings: Water supply; Reservoir operation; Water storage.

An economic-engineering optimization model of California's major water supply system is presented. The model's development, calibration, limitations, and results are reviewed. The major methodological conclusions are that large-scale water resources optimization models driven by economic objective functions are both possible and practical; deterministic models are useful despite their limitations; and data management, reconciliation, and documentation are important benefits of large-scale system modeling. Specific results for California indicate a great potential for water markets and conjunctive use to improve economic performance and significant economic value for expanding some conveyance facilities. Overall, economic-engineering optimization (even if deterministic) can suggest a variety of promising approaches for managing large systems. These approaches can then be refined and tested using more detailed simulation models. The process of developing large-scale models also motivates the systematic and integrated treatment of surface water, groundwater, facility, and water demand data, and identification of particularly important data problems, something of long-term value for all types of water resources analysis. DOI: 10.1061/(ASCE)0733-9496(2003)129:3(155) CE Database subject headings: California; Water management; Optimization; Economic factors.

Over the past eight years, the rhetoric of many pundits, politicians, and preachers has shifted from pronouncements about the beginning of a "post-racial" age to proclamations about the persistence of racism in the social fabric of the West. What of the tenacity of what Willie Jennings has called the "racialized imagination" owes to its genesis in religion?1 What if race is at heart a theological construct? This paper traces the genealogical accounts of Jennings and J. Kameron Carter, two recent contributors to the field of theological race studies,2 and contrasts them with common theological ways of thinking about Christian identity as a return to traditions of Western virtue.3 The paper closes by suggesting a way forward in resisting the sociopolitical order of whiteness through a scandalous mutual participation in joined bodies politic marked by difference and inhabiting shared space. [ABSTRACT FROM AUTHOR]