Where the additional water is coming from

During dry conditions, no additional water is available within Essex to supply the county. Essex has relied on transfers of water from the Ely Ouse in Norfolk to fill its reservoirs since the 1970s, particularly during dry periods.

The Environment Agency currently transfers water from Denver in Norfolk to Essex when it is needed to fill Abberton and Hanningfield reservoirs via the Ely Ouse to Essex Transfer Scheme (EOETS). Under the scheme, surplus water which would otherwise flow to the Wash, is transferred to Essex.

Currently, water from the EOETS meets the following proportion of the demand in Essex:

Wet Year - none required by ESW
Normal Year - up to 7%
Dry Year - 15% to 35%

Due to current pumping and storage constraints, Essex & Suffolk Water cannot always fully utilise water when it is available in the River Stour. The enlarged reservoir and the additional intake from the River Stour at Wormingford will provide the opportunity to abstract and store additional water from the River Stour during high flow conditions which usually occur during the winter.

It is proposed to vary the Environment Agency’s abstraction licences at Denver and Blackdyke in Norfolk, which control the amount of water transferred to Essex.  This will provide the additional water required for potential transfer to fill an enlarged Abberton Reservoir.

A detailed study of the possible effects of the change in volume of water transferred has been ongoing since 1996.

The proposed Denver Licence Variation

The Denver and Blackdyke abstraction licences contain a number of conditions that control the amount of water that can be transferred to Essex.

The licences include a limit on the amount of water that can be transferred in any one day and over an 18-month period.

There is also a condition that requires a minimum volume of water to be flowing past Denver before any transfers can take place. This restriction is known as the ‘Hands Off Flow’. This means that water can only be transferred to Essex when the Hands Off Flow in the Ely Ouse at Denver is exceeded. The Hands Off Flow varies between months.

A number of possible variations to the Denver licence were assessed. The choice of the preferred option for abstraction at Denver was largely based on consideration of potential effects of the variation on sites of high nature conservation value.  The chosen option was considered most likely to deliver benefits for these sites and least likely to cause adverse effects.

It is proposed to increase the total amount of water that can be abstracted over an 18-month period from 79,555 million litres (commencing 1 April each year) to 100,000 million litres.

It is also proposed to amend the Hands Off Flow conditions. The table below shows the proposed changed to Hands Off Flow monthly profile:

Hands Off Flow Condition (million litres)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Current licence	318	318	114	114	114	114	114	114	318	318	318	318
Proposed varied licence	318	318	318	318	114	114	114	114	318	114	114	114

This would mean a reduction in HOF in October, November and December, and an increase in HOF in March and April, resulting in less water being available for transfer in spring but allowing transfer of more water in late autumn and early winter for storage in Abberton Reservoir.

There will be no change in the maximum licensed daily abstraction for transfer via the EOETS, which will remain at 455 million litres.

When is water transferred to Essex & how much will be transferred in the future?

Water is only transferred from Denver to Essex via the EOETS for water supply purposes when all of the following conditions are met:

• the level of Abberton and/or Hanningfield Reservoirs falls below a specified level, which is separately defined for each month of the year;

• there is not enough natural flow in the River Stour or the River Pant/Blackwater to enable abstraction to take place in order to supply the Reservoirs; and

• the full Hands Off Flow is being released from the River Ely-Ouse to the tidal River Great Ouse.

The same conditions will also apply in future under the Abberton Scheme. For information, the EOETS is not currently in constant use, nor would it be under constant use under the Abberton Scheme. 

The amount required from transfer varies year on year depending on rainfall and demand for water. Based on demand in 2004 the average quantity of water transferred in each 18 month period is about 18,000 million litres.  Without the Scheme, this is predicted to rise to about 22,000 million litres by 2027 (and even this would not provide satisfactory security of supply).  With the Scheme in place, the need for transfers would be about 19,000 million litres on average in an 18 month period.    This is because if nothing is done and the additional reservoir and pipeline capacity is not available, then transfers of water from Norfolk would be relied on more frequently in the future to meet rising demand for water in Essex rather than from water stored in an enlarged reservoir.

Denver and Wash Stakeholder Meetings

As part of ongoing communication between Essex & Suffolk Water and the community who might be affected by the Abberton Scheme, three  meetings have been held in King's Lynn in November 2005, May 2006 and June 2007 to discuss the proposals and the investigations that have been carried out..

The meetings gave stakeholders potentially affected by the changes to the Denver licence the opportunity to ask questions and comment on the proposals.