A Warning from the Yakima: Washington's Water Future in a Warming Climate

1 · The Reservoir Map

A geographic snapshot showing all five major reservoirs at critically low levels. The largest, Kachess Reservoir, sits at just 16% capacity. The others? Between 4–19%. The visual is stark: these reservoirs, represented by glass icons on the map, are nearly empty.

2 · 130 Years of Storage Data

A time-series chart of Cle Elum Reservoir showing seasonal patterns from the 1890s to today. The recent years stand out dramatically — water levels that once reliably climbed above historical averages now barely reach half capacity. Three major droughts in the 2010s and 2020s are clearly marked, with the current situation being the worst yet.

3 · The Palmer Drought Severity Index

A color-coded timeline showing wet periods (green) versus drought periods (red/pink) since 1998. The pattern shift is unmistakable: after 2013, the region entered extended drought with increasingly severe episodes. The 2020s show extreme drought conditions dominating the landscape.

Why It Matters

The Yakima Basin supplies water to one of the nation's most productive agricultural regions. These visualizations provide water managers, farmers, policymakers, and journalists with clear evidence that this isn't a temporary dry spell — it's a fundamental shift in water availability that demands immediate action.

The Message

The reservoirs aren't just low this year. They're consistently failing to refill to historical levels, decade after decade. That's not weather variability — that's climate change.

Create a comprehensive water resource monitoring system for the Yakima River Basin that visualizes current reservoir conditions, historical storage patterns, and drought severity to inform stakeholders about the region's water crisis.

Analyze water storage data across five Yakima Basin reservoirs (2012–2025) and Palmer Drought Severity Index data from 1893 to present, creating an integrated visualization system combining geographic context, temporal analysis, and drought metrics.

Enables farmers and irrigation districts to make informed decisions about crop planning and water allocation

Provides evidence for water resource management policies and drought response planning

Custom geographic visualization with styled basemaps, river systems, and interactive reservoir indicators

Integration of PDSI data spanning over a century, with color-coded severity classifications and seasonal smoothing

Visualizing Cyclical Reservoir Patterns

Reservoir storage follows distinct seasonal cycles — filling during spring snowmelt and depleting through summer irrigation season. The challenge was displaying these natural fluctuations while highlighting abnormal drought conditions.

Solution: Implemented reference lines showing both "Overall Average (1961–2010)" and "Annual Low Point Average (1961–2010)" to provide context for normal seasonal variation versus drought-induced depletion. This allows viewers to distinguish between expected seasonal lows and crisis-level storage.

Communicating Current Crisis Severity

With five reservoirs at different capacity levels, conveying the system-wide water shortage required a clear, immediate visual language.

Solution: Designed custom container icons sized proportionally to capacity, with bright cyan coloring for immediate visual recognition against the dark basemap. Positioning reservoirs geographically while displaying percentage values creates both spatial and quantitative understanding.

Connecting Short-Term Trends to Long-Term Climate Patterns

Reservoir data alone might suggest temporary drought conditions, but understanding the broader climate context requires historical perspective.

Solution: Integrated the Palmer Drought Severity Index spanning the last 30 years, revealing that recent extreme drought events (2020s) fit within a pattern of increasing climate volatility and prolonged dry periods since 2013 — demonstrating this is not merely a short-term weather fluctuation but part of long-term climate change impacts.

Reservoir Storage Data

• Source: U.S. Bureau of Reclamation (USBR)
• Coverage: Five major Yakima Basin reservoirs (Keechelus, Kachess, Cle Elum, Bumping Lake, Rimrock)
• Temporal Range: 2012–2025 for detailed analysis (Cle Elum Visual)
• Baseline Period: 1961–2010 for historical comparison
• Measurement: Acre-feet storage capacity

Palmer Drought Severity Index (PDSI)

• Standardized drought metric ranging from −6 (extreme drought) to +6 (extremely wet)
• Incorporates temperature, precipitation, and soil moisture data
• Historical coverage: 1893–present for Yakima County, highlighting the last 30 years
• Provides long-term climate context beyond reservoir measurements

Geographic Visualization (Mapbox)

• Dark theme to emphasize water features and data elements
• Custom styled river systems (Yakima, Naches, Tieton) in cyan
• Custom SVG container shapes representing fill levels with real-time capacity percentages (4%, 10%, 16%, 19%)
• Strategic label placement for readability with geographic reference cities

Time-Series Analysis (Tableau)

• Area chart design emphasizing seasonal storage patterns
• Dual reference lines for overall average and annual low points
• Annotated drought years (2015, 2019, 2021) with contextual callouts
• Gradient color scheme showing depth of storage depletion

Climate Context (PDSI Visualization)

• Three-color classification system: green (wet), yellow (moderate), red (extreme/severe drought)
• Zero-line reference for normal conditions
• Extended time series revealing century-long patterns
• Recent trend highlighting (2013–present) showing persistent drought conditions
• Seasonal smoothing with color thresholds aligned to standard PDSI classifications

U.S. Bureau of Reclamation

Source: USBR Pacific Northwest Hydromet

Dataset: Yakima Basin Reservoir Storage Records

Coverage: Five major reservoirs, 2012–2025

USDA Natural Resources Conservation Service

Source: NRCS Snow & Climate Monitoring

Dataset: Palmer Drought Severity Index, Yakima County

Coverage: 1893–present