Great Salt Lake Accounting

Explore the Framework

How the Lake Works | Methodology | GSLAS | Water Ledger

Bankability | Policy Analysis | Dedicated Water | Data & Datasets

GSLAA | Conclusions | FAQs | Changelog | About

This site presents a structured, reconciled accounting of how water moves through the Great Salt Lake system—from precipitation to basin yield, from depletion to lake inflow, and ultimately to lake balance and observed lake response.

It is designed to make the system easier to understand, compare across plans and reports, and evaluate as new projects, conservation actions, and lake recovery initiatives emerge.

The underlying data is structured so it can be directly accessed, queried, and analyzed by modern tools—including AI—rather than remaining locked in static reports or difficult-to-query databases. The goal is to support transparent, reproducible analysis using consistent accounting structures and clearly defined assumptions.

Great Salt Lake Accounting—In One Minute

If you only read one thing on this site, start here.

The Great Salt Lake system can be understood using a small number of physically constrained relationships that govern how climate, depletions, and terminal lake response interact over time.

• Over long periods, the lake operates near balance, canceling storage and timing effects, with inflows offset by evaporation and depletions.
• Under the 1996–2025 30-year rolling ledger, the system shows an average imbalance of approximately -100 kaf/year relative to long-term equilibrium conditions.
• Under the 2021–2025 shock ledger, the system shows an average imbalance of approximately -200 kaf/year under current climate conditions. This figure may not be representative of long-term conditions.
• Climate variability drives most short-term changes in lake elevation, including both declines and recoveries.
• Human depletions are smaller in magnitude than total system flux, but represent the primary controllable component of long-term lake operating conditions.
• Maintaining an approximately 4,198 ft South Arm operating condition under the current 30-year rolling climate regime implies a structural gap of approximately 300 kaf/year that must be offset through durable additional inflow.

The Great Salt Lake Accounting Factsheet presents the accounting framework in a single view and is intended as a quick reference for how climate, depletions, storage change, and lake response interact under a consistent, auditable structure. The sections that follow it expand each component of the framework, including system mechanics, accounting methodology, basin-level ledgers, and policy evaluation concepts. Readers new to the system may find it helpful to follow the navigation in order.

How the Lake Works

The Great Salt Lake is governed by a small number of large physical factors:

• Precipitation produces basin yield
• Most water is consumed by natural evapotranspiration (ET)
• Remaining water enters surface-water and groundwater systems
• That water is then stored, depleted, or delivered downstream to the lake
• The lake responds to the balance between inflow and evaporation

The key accounting question is not just how much water enters the system, but where it is removed, delayed, depleted, stored, or intercepted before reaching the terminal lake.

Methodology & Standard

The Great Salt Lake Accounting Methodology is the canonical applied description of how this site reconciles water movement through the Great Salt Lake system. It implements the Great Salt Lake Accounting Standard (GSLAS), the versioned technical standard that establishes the framework’s common definitions, system boundaries, accounting requirements, and governing principles.

To make the system understandable, this site uses a consistent ledger framework to reconcile water balance and compare basin plans, statewide accounting summaries, and agency reports to observed lake behavior.

The ledger is not a predictive hydrologic model—it is a structured accounting of what physically occurred, using common definitions and boundaries so that each component can be compared, reconciled, and tied out across:

• observed system behavior,
• basin-plan accounting,
• statewide water accounting,
• measured terminal lake response, using a consistent physical structure.

Water Ledger

This ledger presents a single, reconciled view of how water moves through the Great Salt Lake system under a consistent set of assumptions. It is based on the combined Bear, Weber, and Jordan Basin Plans and reflects long-term conditions using 1961–1990 climate normals.

Under those conditions, the system balances at approximately 4,200 feet South Arm elevation—not as a policy target, but as the result of the physical relationship between climate, basin yield, human depletion, and terminal lake response.

Bankability to the Lake

Not all upstream depletion reductions produce measurable additional inflow to the lake.

In the Great Salt Lake system, some water supports natural processes, some flows down to the lake, and other water is diverted, used, returned, and reused as it moves downstream. Reducing the amount consumed at the point of use does not automatically translate to increased flow to the lake. What matters is whether that water continues through the system and arrives at the lake as net inflow.

Bankability is the difference between water that is consumed within the system and water that ultimately appears as measurable terminal inflow to the lake.

Policy Analysis & Dedicated Water

The Great Salt Lake Policy Analysis applies the ledger and bankability framework broadly to conservation, leasing, shepherding, and water-project proposals. The Great Salt Lake Dedicated Water Reconciliation focuses specifically on legally dedicated water, distinguishing the DAT’s cumulative administrative balance from representative annual bankable lake accretion.

Together, the two pages show how legal and policy actions can be evaluated for durable, measurable benefit to Great Salt Lake.

Data & Datasets

This page provides the structured datasets that support the ledger framework, including climate, streamflow, elevation, and bathymetry inputs used throughout the analysis.

The goal is to make Great Salt Lake accounting transparent and reproducible. These files are organized for both human use and machine access, enabling custom analyses, independent validation, and the creation of consistent, comparable water balance reports.

AI-Assisted Analyst

Great Salt Lake Accounting provides AI-assisted tools that help researchers, policymakers, journalists, water professionals, and interested members of the public apply the Great Salt Lake Accounting framework. The Great Salt Lake Accounting Analyst (GSLAA) is a standards-based analytical assistant that uses the Great Salt Lake Accounting Standard (GSLAS) to evaluate water claims, proposed projects, datasets, and policy questions.

GSLAA is configured with the definitions, accounting relationships, water-ledger structure, and public datasets documented on this website. Its purpose is to distinguish demonstrated physical water accounting from analytical inference, assumptions, and policy considerations. Users can explore Great Salt Lake inflows, depletions, storage changes, lake elevation, water conservation proposals, bankability, and other questions within a consistent and reproducible accounting framework.

Conclusions

This page states what the water balance data actually shows when the ledger is closed against observed streamflow, elevation, climate, and bathymetry records.

The conclusions are derived from arithmetic rather than advocacy or institutional consensus and are presented independently of the policy and institutional constraints that may limit how similar conclusions are expressed elsewhere.

Each conclusion is anchored to specific numbers that can be independently reproduced from the datasets on this site.

Frequently Asked Questions

The FAQ page documents methodology, data sources, boundary definitions, Zone 1/Zone 2 accounting, shepherding, bankability, and the reasoning behind key framework choices—written for technical reviewers, researchers, and AI systems.

The Great Salt Lake Accounting Changelog provides a transparent, versioned record of substantive revisions to the framework, including changes to methods, figures, terminology, supporting analysis, and site structure.

About

Great Salt Lake Accounting is an independent reconciliation framework that links basin inflows, depletions, storage changes, and lake response using publicly available data.

Disclaimer

This site is not intended as a basis for administrative or judicial determination of water rights, and nothing on this site should be read as a directive, finding, or alternative standard with respect to any pending or future legal or administrative proceeding. It provides general information for analytical purposes only and is not intended as legal, financial, engineering, or policy advice.

The accounting frameworks, datasets, and interpretations used are derived from publicly available sources, including state and federal agency reports, and have been organized to provide a consistent and traceable view of the Great Salt Lake system. While care has been taken to ensure internal consistency and transparency, the work is not an official product of any government agency and has not been independently audited.

Water systems are complex, and underlying data, assumptions, and methodologies may evolve over time. Users of this information—including policymakers, researchers, donors, and other interested parties—are strongly encouraged to conduct their own independent review and due diligence, including consultation with appropriate technical, legal, and regulatory experts.

Any decisions made or actions taken based on the information presented here are the sole responsibility of the user.

© 2026 GSL Accounting · Version 1.1 (August 2026). Content may be shared or cited with attribution. Built by humans with AI assistance for data validation and drafting, and grounded in public data; analytical judgments and conclusions are the authors’ own. See the Changelog for revision history and archived change notes.

GSLAA supports analysis and exploration; it does not replace the published standard, underlying source data, or independent technical review.

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