Colorado River Basin Natural Flow and Salt Data

The provisional natural flow is an early estimate of natural flows at the Colorado River at Lees Ferry, AZ. It is provided to give water operators and stakeholders insight into the natural flows since the most recent published year. Estimates depend on Reclamation's 24 Months Study and are published following the completion of the January, April and August studies. Estimates are developed from either the historical unregulated inflow or the forecasted unregulated inflow into Lake Powell from the Colorado Basin River Forecast Center (CBRFC). Estimates from previous studies are provided to help users understand the evolution of the provisional natural flow. Provisional data are not used for modeling purposes in CRSS.

Please note that data is SUBJECT TO CHANGE over the entire record due to source data updates.

Natural Flow and Salt Data Index

Current Natural Flow and Salt Data
      Documentation
      Natural Flow Supporting Data
      Natural Salt Supporting Data

Previous Natural Flow and Salt Data

Provisional Natural Flow Data
PROVISIONAL natural flow data 1906-2022 (Excel file, 0.3 MB) based on the October, 2022 24 MS

PROVISIONAL natural flow data 1906-2022 (Excel file, 0.3 MB) based on the April, 2022 24 MS.

PROVISIONAL natural flow data 1906-2022 (Excel file, 0.3 MB) based on the January, 2022 24 MS


Contact: bcoowaterops@usbr.gov
Last Updated: 15NOV2022