Water Supply Difficulties January 2010

For water supply purposes Dublin is treated as a Region covering the counties of Dublin South, Fingal, Dun Laoghaire Rathdown, Wicklow, Kildare and Dublin City.

2 of these collect, treat and deliver water to all 6. These being Dublin City Council and Fingal County Council.

Untreated water is collected and stored for treatment at reservoirs at Poulaphouca, Roundwood, Bohernabreena and Leixlip.

This untreated water is then treated at 4 water treatment plants as follows:

  • Ballymore Eustace on the River Liffey, operated by Dublin City Council
  • Roundwood on the River Vartry, operated by Dublin City Council
  • Ballyboden on the River Dodder, operated by Dublin City Council
  • Leixlip on the River Liffey, operated by Fingal County Council

Treated water is then delivered to consumers via large diameter watermains and a series of treated water reservoirs sited throughout the area to be supplied. The most significant of these include:-

  • Stillorgan Reservoir
  • Ballyboden
  • Balllycoolin
  • Cookstown
  • Belgard
  • Peamount
  • Woodtown
  • Rathmichael

The treated water reservoir at Stillorgan is the largest of these and is of vital importance strategically since a large part of the network is reliant on it for supply.

From these reservoirs watermains distribute supplies to the customers in all parts of the city in our case.

The average daily demand for drinking water in the Region for 2009 was 540 million litres per day.

During the recent cold spell of weather demand rose to unprecedented levels and peaked at 634 million litres on Sunday January 10th.

Storage levels of treated water reduced to critically low volumes as a result of high demand exceeding our ability to replenish stocks. This increased demand arose for a number of reasons including:-

  • Bursts on watermains
  • Bursts on supply systems on private property
  • Consumers leaving taps turned on in order to try to prevent internal plumbing systems from freezing.

This resulted in a serious reduction in the level of service that could be provided and many areas experienced a reduction in pressure or a total loss of supply.

Much of Dublin City’s water distribution network is old and in need of replacement. Old cast iron pipes are prone to fracture, particularly during and immediately after cold weather events. Some capital funding has been made available by Central Government to begin a replacement programme but there is a need for a commitment to continue to provide the funding that will be required to complete the task.

The vast majority of watermain leaks in Dublin City do not appear at the surface as water escapes underground. This makes finding them difficult.

The technology used to detect and locate leaks depends on noise created by water escaping from pipes in order to be successful. As water pressures are reduced the level of noise created by leaks is greatly diminished which presents difficulties for detection crews.

Treated water storage levels must be restored in order to allow an increase in pressure to assist in finding broken watermains.

In order to replenish storage all of the local authorities have had to impose severe restrictions on supply. This has caused great inconvenience to all consumers and for this we apologise. It will be necessary to keep some level of restriction in place for an extended period while delivering a reasonable, although limited, level of service.

The situation, as of Sun 17th January, is showing signs of stabilising and there has been a slight improvement in storage levels. This has allowed the raising of pressures which is providing some respite for customers and is also resulting in a significant number of bursts being detected. These are being repaired as quickly as they are being found with crews working long hours.

Demand peaked at 634 million litres per day on January 10th. This was reduced to 536 million litres by January 17th through a combination of customer co-operation, finding and fixing leaks and the imposition of restrictions on supply by all of the Region’s Local Authorities. The bulk of this improvement occurred over a weekend and weekday demands will be higher. It will therefore be necessary to continue to have restrictions in place and these will affect customers in all parts of the city at different times.

Treated water storage at the most critical of our reservoirs, Stillorgan, has risen from a low of 402 million litres on January 15th to 440 million litres on January 17th. This figure needs to rise to at least 550 million litres before consideration can be given easing the restrictions currently being imposed. Treated water storage at the other reservoirs is also recovering to more desirable levels.

Where broken mains occur, customers in the vicinity of the break will experience difficulties over and above any restriction in place as part of demand reduction measures being implemented.

Areas in the North of the City, particularly those on higher ground, will experience ongoing problems in the short term as efforts to improve pressures continue. Pressures tend to improve slightly overnight but reduce during the day as demand rises.

Severe restrictions being imposed on the Southside of the city will continue to be in place and customers will experience a reduction in service, including loss of supply, for periods until treated water storage levels improve.

Tankers are deployed to a number of fixed locations with others being mobile to serve new problem areas and to deliver temporary supplies to local areas with specific problems. Details of the fixed tanker locations are available on Dublin City’s website www.dublincity.ie which is updated a number of times each day.

Tankers fitted with pumps and fire engines, provided by Dublin Fire Brigade and the Civil Defence, are being used for supplying hospitals, nursing homes and schools.

Deliveries to the homes of the elderly or customers with special needs are being made where possible depending on the level of demand and the resources available.

Water Services have 50 of their crews, supported by office based staff, working to address the current difficulties as speedily as possible. These are involved in providing water tankers and standpipes to get temporary supplies to consumers including individuals, hospitals, nursing homes, schools etc. and to those with special needs. They are also working to detect and repair leaks on watermains and managing the distribution of the available water supply. Staff have been working virtually round the clock on behalf of customers and as result of their efforts and the assistance of those listed below the supply situation is stabilising and good progress is being made towards a return to more normal levels of service.

Assistance and support is being provided to Water Services Division by Drainage /Wastewater Services Division, Waste Management Division, Parks Department, Civil Defence, Dublin Fire Brigade, Defence Forces, Diageo, Area Offices, Press Office, the Customer Services Centre, the elected representatives and our colleagues in the other Local Authorities in the Region. We would like to acknowledge and express our appreciation to all of those who are supporting our efforts.