Water Resource Assessment

Over recent years the UK has experienced atypical weather: much of central, eastern and southern England and Wales experienced a prolonged period of below average rainfall from 2010 to early 2012. This was one of the ten most significant droughts of one to two years duration in the last 100 years. Across southern England, the two-year period April 2010 to March 2012 was the equal-driest such period since 1910 (shared with April 1995 to March 1997).


By March 2013 the implications of even a normal Summer’s rainfall were potentially severe for several water companies in the South East. Fortunately (from a water resources perspective), the exceptional drought was followed by the wettest summer and winter on record resulting in groundwater levels going from record low to record highs in 6 months.


This might be seen as a one-off occurrence, but it follows another close shave in 2004-6, when water companies worried about the prospects of a third dry winter were relieved by a wet summer in 2006. Whether these events will be seen in retrospect as exceptional or part of a new normal, it is clear that understanding the response of natural systems to large variations in rainfall is increasingly important to a wide range of stakeholders, but particularly water companies.


We have been working with water companies and the Environment Agency over the last 14 years to develop tools to support management decisions about water resources. Our approach is based on three core strengths:

  • Understanding the key drivers, both regulatory (e.g. Water Framework Directive and CAMS) and from the natural environment (drought and flood)
  • Strong technical skills in the analysis and modelling of groundwater and surface water systems at both borehole and catchment scale; and
  • Clear understanding of our clients’ requirements, both for the Environment Agency and water companies


We have core skills and experience in developing regional groundwater/surface water models for the Environment Agency, and have expanded these into areas including review of consents affecting wetland sites, borehole yield and asset management, drought permitting and management of large and complex low flow investigation programmes. Where appropriate we have worked closely with partner organisations provide to an even wider range of skills to our clients (e.g. hydro-ecology, hydrometry and environmental economics).


As well as the pressures on water resources from droughts, it is estimated almost half of the groundwater used for public supply is now affected by quality problems. Already, with rising nitrate concentrations throughout the country, most of the scope for blending groundwater to meet drinking water standards has been exhausted. Water companies are increasingly looking to catchment management solutions to avoid costly treatment solutions. In recent years we have worked with a number of water companies to investigate the feasibility, practicality, timeliness and cost effectiveness of catchment management options.


Whilst the trend within the industry is to downsize internal technical teams and to contract out much of the project management to large, multi-sector consultancies, our discussions with our clients in the water sector indicate a clear role for specialist consultancies such as ESI with our great depth of experience and technical expertise in water resources.

Please contact us for more information on our Water Resource Assessment service.