A cafe owner facing a 51pc hike in her annual water bill has denounced the increase as “very unfair”.

Colette Kohler is one of thousands of small-business owners throughout Ireland who have received letters from Irish Water about a new tariff regime for those whose water use is not metered.

Her annual water bill will rise by €170 to €503 on October 1.

“It’s very unfair on small businesses like mine to be facing such a big increase after we were forced to stay closed for so long by the pandemic,” said the 61-year-old mother of four. 

“They should give us a chance and not impose any increase in water charges for the next two years.”

Ms Kohler has been running the Scrumptious Café on Philipsburgh Avenue, Dublin, for the past six years and employs three part-time staff.

Irish Water told the Sunday Independent that hundreds of different water tariffs around the country were being harmonised into a simpler system that will mean charges could go up or down for unmetered business customers.

Ms Kohler said: “It’s so unfair as we’re only starting to pick up business now. For us, outside dining isn’t working when the rain comes.

“I’ve had a lot of bills and I shouldn’t have to pay such a big increase for water. We’ve lost over a year of business from the restrictions. Irish Water should hold off any increase for two years to give us all a chance until we find our feet. I was shocked to get this bill.”

She added that another business near her is also facing a €170 increase in its water in water bill.

Irish Water said there has been no increase in charges for unmetered businesses since 2014 and even longer.

The harmonisation of bills will mean nearly half of all such customers will see a decrease in their bills.

Around 4pc of 180,000 business customers have unmetered water supplies.

The Commission for the Regulation of Utilities approved the tariff harmonisation, and the new charges were due to begin in May last year, but were deferred twice because of Covid-19.

Yvonne Harris, head of customer operations at Irish Water, said: “Irish Water understands the continued challenges faced by businesses. Our aim is to ensure that every business across the country is provided with a clear, transparent, equitable charging regime regardless of location.

“Currently, there are over 500 different tariffs, with customers in different local authority areas paying different charges. The new framework will standardise charges across the country while recovering the cost of providing water and wastewater services to non-domestic customers.

“To ensure the changes are clearly communicated, we are currently writing to all customers, outlining what the changes mean for them.

“The vast majority of customers will see either a decrease or an increase of less than €250 per annum, in their annual bills.

“For the minority of customers who will face larger increases in their annual bill, Irish Water will put in place a number of important support measures.

“Connections that see an increase of €250 or more will be gradually transitioned to the new tariffs over three years.

“For connections that will face an increase of €750 or more, we will automatically apply a 10pc cap to their annual bill increase in any one year.

“Throughout this process, both Irish Water and the Commission for Regulation of Utilities have examined international best practice and consulted with representative groups and individual businesses across the country.

“This approach has greatly helped in developing charges that are clear, simple and fair to all.”