Winter 2011-2012 Drought Permits and Drought Monitoring

The cool and cloudy summer of 2011 disguised the extremely dry conditions that occurred during the year: parts of central and south eastern England experienced the driest 12 months on record and groundwater levels and river flows are at historic lows for this time of year.  Combined with the very dry soils across the country, this means that even with average rainfall in winter 2011/12 many parts of the country will experience drought conditions in summer 2012. Meanwhile the Environment Agency has issued an updated Drought Prospect report concluding that:

The rainfall received during December and the early part of January in central, eastern and southern areas of England has contributed to a small recovery of river flows and groundwater levels but soils are still relatively dry for this time of year. Therefore these areas remain at high risk of drought later this year unless we have prolonged periods of rainfall. Drought could have significant impacts on the environment and habitats, agriculture and navigation. It may also lead to more drought permits and customer restrictions on public water supplies remain possible. 

The latest Environment Agency report can be read here. 

In response to these conditions, Anglian Water has been granted two Drought Permits by the Environment Agency to top up the Pitsford and Rutland Water reservoirs, which will be effective until the end of March and the end of April 2012 respectively. South East Water has been granted a Drought Order to protect supplies for the Ardingly reservoir which will operate until the end of March 2012. Several other water companies are currently monitoring the situation very closely before deciding whether to apply for Drought Permits.

Drought Permits and the associated drought monitoring require a comprehensive range of specialist services. ESI, supported by APEM and Hydro-Logic has recently completed Environmental Assessment Reports to support a potential application by Severn Trent Water for Drought Permits on the Derwent and Churnet catchments. This work required a detailed assessment of the potential impacts of the Drought Permits on the local ecology and, in close consultation with the Environment Agency and Natural England, the development of appropriate mitigation measures.

Since 2010 ESI and partners have also been carrying out associated monitoring of the stream flows and ecology in these catchments.  The ESI led team has recently been commissioned by Severn Trent Water to develop Environmental Assessment Reports for potential Drought Permits on the Leam, Wye and Severn at Trimpley.

What is a Drought Plan / Permit?

Water companies have a statutory duty to produce Drought Plans in order to manage water resources effectively during a drought. The Environment Agency produces its’ own Drought Plans that outline the actions it will take to protect the environment during a drought. These plans will include options to increase temporarily the abstraction of water to protect public water supply or the environment. The latest updates of Drought Plans for most water companies and the Environment Agency will be published in the next few weeks.

Most abstractions, including those for public water supply, are controlled by abstraction licences issued by the Environment Agency. These constrain the amount of water that may be abstracted under normal conditions and may restrict this further in dry conditions, or may place certain mitigating measures on the water company to protect the environment and/or other users. 

Drought Permits and Drought Orders are drought management actions that can allow water companies more flexibility to manage water resources and the effects of drought on public water supply and the environment, for example by changing abstraction licence conditions.

Application for Drought Permits and Drought Orders require an Environmental Assessment Report, which provides details of baseline conditions and assesses the potential impacts on the water environment from implementation of the Drought Permit. Where potentially significant negative impacts are identified, the reports identify appropriate mitigation measures.  In addition the reports include an Environmental Monitoring Plan (EMP) to set out the monitoring that is needed to determine the effect of the operation of the Drought Permit. 

Prospects for groundwater levels in Midlands Region (December 2011)

ESI has recently analysed groundwater levels in the Permo-Triassic Sandstone aquifer, the most significant source of Public Water Supply within the Midlands. Normally the large amount of fresh water stored in this aquifer means that the region has a reasonable tolerance to drought conditions. However, with no significant recharge occurring to the aquifer since 2009, groundwater levels are already at a level only seen in the worst droughts over the last 40 years and are still falling.

ESI’s analysis of trends in groundwater levels from December in each year since 1971 shows that there is a significant risk that groundwater levels will fall to an all time low in 2012 (see graphic below).