2025 End of the Year Critical Period Calculator

This auto-fill calculator allows you to accurately determine how much water you may need to transfer for 2025, or how much water you may have remained, by entering your total pumped amount (required) and total authorized amount (if known). To use, simply select the pool for your area and the program will automatically display the stage(s), number of days, and applicable reduction rates. To calculate the total permit authorization needed to cover your total use plus reductions, enter your annual authorized groundwater withdrawal amount in the appropriate box and click the Calculate button. If you know your total authorized amount for the year, you can also enter that in the appropriate box. Your total authorized amount needed for the year is displayed in red. Reset the calculator each time to repeat the process as necessary.

Note: Our interactive Critical Period Calculator allows you to determine how much water you need to have authorized to cover your total use and total critical period reductions for the year”. “Please note, this calculator is only available 12/31 – 1/31, when we know the reductions for the year.