WATER SUPPLY in the greater Dublin area is on a knife-edge, with demand likely to outstrip available reserves within a few years, according to a report prepared by consultants for seven local authorities.
The capital has no strategic reserves of water when it should have 10-20 per cent reserves at a minimum, while existing sources are operating near sustainable limits, the report by consultants RPS-Veolia JV states.
Dublin city councillors this week approved the consultants’ main proposal to bring excess water from the basin of the Shannon river to meet needs in the east and midlands.
The decision was taken by the council’s environment and engineering strategic policy committee (SPC) following a presentation by the consultants working for the Dublin Supply Project.
It is expected to be confirmed by the entire council later this year and will then go to An Bord Pleanála following a six-month consultation period.
The plan, the first major water supply project since the Liffey was dammed at Poulaphouca and Leixlip in the 1940s, will cost €470 million to construct over 10 years, with annual operational costs ranging from €8-15 million.
The report says the Dublin region is again approaching the stage where new long-term, secure and sustainable supplies of water are critical to its development and to the performance of the State.
“It has to be done; there is no other way,” said Fine Gael councillor Naoise Ó Muirí, who chairs the environment and engineering SPC.
The cost of operating desalination plants was too high, while international experience showed it was very difficult to reduce leakage below 20 per cent, he added.
There are currently four main water treatment plants in the greater Dublin region, which includes Kildare, north Wicklow and parts of Co Meath in addition to the capital. Their maximum output is between 540 and 550 million litres per day, while under normal circumstances demand is between 530 and 540 million litres per day.
The lack of space capacity in the Dublin system contrasts with Paris, where three treatment plants operate at just 60 per cent capacity.
The report says the fragility of the situation was starkly illustrated when increased leakages caused by last January’s cold snap led to restrictions in supply.
Leakage from the system has been reduced from 42 per cent in 1996 to 28 per cent in 2002, but the report says that the maximum supply levels will be reached in the 2020s despite further efforts to reduce leakage.
The report also points out that customer leakage losses average 65 litres per property per day, broadly comparable to the UK. It says this figure could be halved following the introduction of water metering.
“If a new source is not provided, the consequences would be supply restrictions of increasing frequency with impacts on social and economic interests combined with constraints on new development including employment generation in the region,” it warns.
A number of multinationals with plants in the region, such as Diageo, Intel and Wyeth, have expressed concern about the security and/or quality of water supplies, it is understood.
The report considered 10 different supply options, seven of them with the Shannon as the source, as well as a number of sites for desalination.
The preferred option, which involves taking the water from a point north of Lough Derg and piping it to a reservoir at a cutaway bog at Garryhinch, close to Portarlington, Co Laois, where it would be treated and distributed, involved the minimum cost, according to the consultants.
The Shannon proposal has met strong opposition from communities in the region, and local and national politicians.