Benchmark Network

The UK Benchmark Network (UKBN) comprises a subset of stations from the national hydrometric network that are most suited for identification and interpretation of long-term hydrological variability and change. Benchmark catchments can be considered reasonably free from human disturbances such as urbanisation, river engineering, and water abstractions, so are ‘near-natural’ and hence can be used for detection of climate-driven changes in river flow. 

The UKBN was originally designated over 15 years ago by Bradford and Marsh (2003). The first iteration of the Benchmark Network, UKBN1.0, included 119 catchments that had (i) relatively natural flow regimes, (ii) good and consistent hydrometric data quality, (iii) long record lengths (>20 years), and (iv) broadly representative of UK hydrology.

It is recognised that the benchmark criteria are stringent and not all stations will meet these fully. This second iteration, UKBN2.0, has made the following updates and improvements:

  • Engagment with each of the 4 measuring authorities (EA, SEPA, NRW, and Rivers Agency) in an expert consultation exercise to gain more detailed information and confirmation about the ability of each station to capture both high and low flow extremes
  • Each station has been assigned a score based on their benchmark suitability at low, medium, and high flows, recognising all stations cannot be benchmark across the full flow regime and provided justification.

The UKBN2.0 is due to be released soon - updates to follow.