Water Resource Zones (WRZs)

Boundaries, names and water balance categories for the 128 water resource zones in England and Wales. Water balance categories are calculated for each water resource zone using Water Resource Management Plan 2024 metrics – 45BL Baseline Distribution Input and 50BL Baseline Supply Demand Balance for 2029-30. Please note that this data does not reflect the actual current resource position, but instead gives an indication of the water resources pressures faced. For more detail on how the Water Balance categories are calculated see below map". Last update 22/08/2025 17:01

Water balance categories shown are baseline forecasts from Water Resource Management Plans (2024) submissions. Baseline forecasts give an indication of the forecast dry year situation supply demand balance for 2029-30, the final year of the current five year AMP8 period, as a percentage of demand (distribution input) without investment from the water industry. Interventions by water companies outlined in their water resource management plans aim to address any forecast deficits. Please note that this data does not reflect the actual current resource position, but instead gives an indication of the water resources pressures faced. Supply demand balance was divided by distribution input and the resulting percentage was allocated to a water balance category as follows:

  • Surplus - High over 10%
  • Surplus - Medium 5-10%
  • Surplus - Low 0 to 5%
  • In balance - 0
  • Deficit - Low 0 to -5%
  • Deficit - Medium -5 to -10%
  • Deficit - High over -10%
The information contained within these Water Efficiency maps is provided to MOSL by water companies and the Environment Agency, and MOSL gives no warranty and accepts no responsibility or liability for the accuracy of completeness of the information on this website. We will not be liable for any reliance on the information on this website or for the non-availability of the website. The boundaries shown are indicative and are not intended to be used at the individual premise level. MOSL takes no responsibility for determining supply boundaries. For specific queries relating to supply please contact the relevant water companies directly.
 
Disclaimer
Postal Boundaries © GeoLytix copyright and database right 2012 Contains Ordnance Survey data © Crown copyright and database right 2012 Contains Royal Mail data © Royal Mail copyright and database right 2012 Contains National Statistics data © Crown copyright and database right 2012. GIS vector data. This dataset was first accessioned in the EDINA ShareGeo Open repository on 14 March 2014 and migrated to Edinburgh DataShare on 22 February 2017.
 
 

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