Slurry wizard

March 2025 update – latest changes
Slurry wizard: A tool to calculate the volume of slurry produced on farm
What does the tool do?
User guide

Our slurry wizard enables you to work out your slurry storage requirements and explore different storage scenarios to comply with regulations.

March 2025 update – latest changes

Modified reception pit calculation
Farmers are now able to enter their own 2-day rainfall value (if known)
Updated cost benefit calculations
Redundant VBA coding has been removed

Slurry wizard: A tool to calculate the volume of slurry produced on farm

By entering basic farm information such as animal numbers, yard/roof areas that capture rainfall and housing periods, the wizard calculates the volume of slurry that the farm will produce on a monthly basis.

This data, together with the farm’s current slurry storage capacity, is used to calculate how long it takes to fill the available storage and whether more capacity is needed.

Note: the wizard will only function correctly if you have Microsoft Excel installed on your device.

What does the tool do?

Calculates the total amount of nitrogen produced to allow those farming within an NVZ to meet the obligation to stay beneath the required threshold
Helps you explore the potential impact and cost from changes to infrastructure such as redirecting rainwater, roofing dirty yards, increasing storage capacity or installing a slurry separator
Provides a cost/benefit analysis for fitting rainwater goods to redirect clean water and covering dirty yards
Allows you to understand the impact of changes by quantifying them, such as: increases in herd size, moving from straw yards to cubicles, introducing outside loafing areas, changes to the housing period and dirty water management

Recent changes to the wizard provide more accurate rainfall data. The tool now uses rainfall data from the Centre for Ecology and Hydrology’s 1 km dataset. To access this data, the farm location needs to be identified with a 10-figure grid reference.

The wizard incorporates a calculation for pig wash water. A wider range of available bank slopes for earth-banked slurry stores and the ability to incorporate slurry bags have also been added.