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Colorado Snow Survey Colorado Reservoir Products
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Maps of Current Colorado Reservoir Conditions

Statewide Reservoir Storage Summery

Calculating current Colorado statewide reservoir storage...

Current Reservoir Storage and Storage Averages in Basin

Below are several interactive maps of current reservoir station and basin storage conditions as a percent of median in Colorado. Click on individual markers to see more details of conditions at a given reservoir. The Colorado Snow Survey does not collect data for all reservoirs in the state but data for a subset that indicates storage trends. Reservoir deltas are the change in the amount of storage from the previous month as a percent of the median delta for that period. For generating static maps as pictures or portable document format (PDF) documents, see the instruction on our frequently asked questions page.

Charts of Colorado Reservoir Data

Below are interactive bar charts, line charts, and radar plots of current and historic Colorado reservoir conditions. Reservoir data is collected on the first of each month and typically takes up to 7 days from the first of the month for reservoir data to populate. Current and historic reservoir values are compared to the 1990-2020 reservoir medians.

A variety of options are listed below each chart. Each chart can be viewed full screen by clicking the "Fullscreen" button below the chart. Plotted data can be turned on or off by clicking on a item in the chart legend. Additionally, a chart can be zoomed or panned using a mouse or touch screen. The "Reset Zoom" button below each chart will reset the zoom and pan to show the fullest extent of the data plotted. Click the "Download" button below the graph to download a static png image. For the best user experience, please use modern browsers such as Chrome, Edge, or Firefox.

Reservoir Storage as a Percent of Median Plots

Below is a bar graph of current reservoir conditions as a percent of median. The year and basin can be adjusted by the dropdown buttons below the chart.

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Reservoir Departure from Median Plots

Below is a graph of reservoir storage departure from the median. This graph shows how many 1000-acre-feet of water a given basin differs from the median for a given time of year. By default, the graph shows statewide departure data for the full period of available years. Alternatively, other basins can be toggled on or off and individual water years can be selected. The data can also be presented as a bar graph by selecting "Bar Graph" in the dropdown below.

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Reservoir Storage Volume Plots

Reservoir storage can be viewed as radar plots or optional bar charts of current reservoir conditions compared to the 30-year median. These plots are useful for visualizing the actual storage, measured in 1000 acre-feet, in a basin at a given time. The default radar plot shows current statewide basin conditions as a polygon of total storage and a second polygon of median storage. Using the dropdown menu below the plot, the year, month, and basin can be changed to show individual reservoir storage in a selected basin at a specific time.

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Colorado Reports and External Resources

Reports for Colorado Reservoir Conditions

Select State, Report Type, Calendar Year, and Publication Date then click the "Submit" button.

Report Type:
Calendar Year:
Publication Date:

Help with New vs. Old Report Comparison: Precipitation Snowpack Reservoir 


External Reservoir Products and Links

Colorado Division of Water Resources Data Portal

Data portal for Colorado Division of Water Resources. Here you can access reservoir, diversion, and streamflow data. These products are producted by the State of Colorado Division of Water Resources.

Bureau of Reclamation Portal for Colorado Reservoirs

Data portal for Colorado reservoirs with more up-to-date hourly and daily data on current reservoir storage conditions. Website is managed by the Bureau of Reclamation.