The water supply situation to 12.00am last night was as follows:
3rd January 2011
Production: 541.7Mld Demand: 516.7Mld
This means we gained 25Mld during the day. Storage at Stillorgan is at 603Mld this morning. On the issue of storage I would like to remind you of what we are trying to achieve. At the original briefing session with Councillors on 7th December 2010 we provided details in this regard. We advised that for the region (taking all of the reservoirs into account) it would be preferable to have about 1050Mld in storage but that the storage level in the Stillorgan Reservoir is the critical factor.
I set out hereunder what the situation was before the bad weather commenced on 22nd November 2010, the current situation (as at 4th January 2011), and what the preferred position would be should we face another extremely cold spell.
Reservoir 22nd Nov 2010 4th Jan 2011 Preferred Position
Stillorgan 702Mld 603Mld 700-750Mld
The experience at the beginning of last year highlighted the need to be able to deal with surges caused by either extremely cold weather or the very quick thaws that can follow. By having over 700Mld in storage at the end of November put us in a much better situation for dealing with the severity of the cold spell before Christmas and the post St Stephen’s Day thaw. The thaw cost us an unprecedented 130mld in two days alone. While the restrictions in the past week were severe the number of areas that had no water for over a day was much reduced on the January event. This is why it is so important to build up adequate storage. In effect we need to have an additional 100-150Mld in storage at Stillorgan.
Today is obviously an important day as many businesses are returning to work after the Christmas break. Taken with the decision to reduce the hours of restrictions and to commence staggered cut offs in those areas worst affected, a picture should emerge by Thursday as to how quickly we can get back to a more normal pattern of usage. Subject to how the situation develops, it is our intention is to be back to pressure reductions only by next Monday 10th January 2011. The base hours for restrictions over the next few days are set out below.
Tue 4th Jan (pressure reductions and cut offs) – 7pm to 7am 5th Jan
Wed 5th Jan (pressure reductions and cut-offs) – 7pm to 7am 6th Jan
Thurs 6th Jan (pressure reductions and cut-offs) – 7pm to 7am 7th Jan
John Tierney, City Manager