NI Water has said it will need more funding to provide the infrastructure required for economic development including new homes in the Newry area.
The council area of Newry, Mourne and Down is one of the locations identified by the company as places where housing and businesses may be unable to gain connection to sewerage systems, because NI Water doesn't have the means to fund them.
It has said that it needs to make a £2.5bn investment for the future but that its shareholder, the Department for Infrastructure, faces competing demands for the funding.
NI Water's Ronan Larkin updated members of Newry, Mourne and Down District Council on the funding needs for water infrastructure in the area. By 2030, Newry Mourne and Down District Council hoped to build nearly 15,000 new homes, while it also hopes to have attracted 9,000 new jobs.
The towns of Newry and Downpatrick have been identified as the main locations for population and economic growth. But Mr Larkin, NI Water's director of finance and regulation, said the company can only spend within its annual public expenditure budget and plans for water and wastewater can only be realised if they are funded.
He said that the company's top priority was providing safe drinking water.
But constraints in its capital budget meant that wastewater issues had "largely been left unaddressed".
"Our PC21 (price control for the five years from 2021) business planning process has identified 99 areas where new housing and businesses may be unable to get connected to our sewerage system throughout the province," Mr Larkin said.
And he said the funding made available for waste and wastewater infrastructure by the NI Government in the 2015 to 2021 PC15 "is not keeping pace with what Northern Ireland needs".
He added: "Significant investment is needed for wastewater and water infrastructure. NI Water knows Northern Ireland's growth ambitions, we know what needs done and we have the plan and the skills to deliver it.
"However, if funding continues at current levels there will be significant constraints on economic growth, damage to the environment and risk to people's health."