Tanks but no tanks - developer launches plans for drainage ponds to help alleviate flooding

THE developer behind a major housing scheme in Antrim has scrapped plans for attenuation tanks to help prevent flooding and instead has submitted a pre-application notice to Antrim and Newtownabbey Borough Council to provide ‘basins’ instead.

Antrim Construction Company was granted permission to build the sprawling Belmont Hall project on the banks of the Six Mile Water in 2018.

Planning permission granted for the 393 dwellings at Belmont Road contained a condition which advised that ‘the surface water drainage regime...should be carried out in accordance with the proposed attenuation tank...to be completed and made operational prior to the occupation of any dwelling associated with each phase of development’.

But as yet, the attenuation tanks - which trap rainwater and release it incrementally back into the watercourse - have not been installed.

That was news to homeowners like Dawn Aiken, who has a property in Riverside which has flooded a number of times, most recently in early November, with the level of the Six Mile Water rising perilously close again at the end of December. Both incidents also left the road outside impassable - a nightmare for residents of the historic one-way street.

A spokesperson for Antrim and Newtownabbey Borough Council told the Antrim Guardian: “The Council has been advised that attenuation basins are being created at Belmont Hall and is now in receipt of a PAN (pre-application notice) from the applicant regarding the submission of a Major Planning Application to provide attenuation basins as an alternative to installing tanks.”

Documents lodged just before Christmas show that Antrim Construction Company is indeed planning: “Two drainage attenuation basins and associated infrastructure, compensatory flood storage area, public open space, landscaping and associated site works.”

Ms Aiken met with DUP Antrim Town councillor Paul Dunlop and a planning officer at Antrim Civic Centre last week to voice her disquiet.

There was also due to be a site meeting in Riverside last week with the Department for Infrastructure and DUP South Antrim MLA Trevor Clarke, but this did not take place.

She has asked for a hydrology report, while Mr Dunlop said that Riverside residents have his ‘full support’.

Ms Aiken said: “I feel a bit let down to be honest. Residents were promised that these tanks would be put in and would be an answer to the flooding and it hasn’t been done, and yet I am only finding out about it now.

“It is my understanding that the Rivers Agency doesn’t actually agree with these basins or ponds because of the level of maintenance required, they prefer tanks - the Rivers Agency won’t maintain these ponds, so will the developer?

“The last flooding incident left my property under four inches of water. During the previous flood, UUP councillor Paul Michael helped get a tanker in and the road was siphoned, but this time, that didn’t happen and people were stuck in their homes all day.

“These floods are definitely getting more frequent, the more that building happens up stream, the water has nowhere else to go, and we are at the bottom of the river before it enters Lough Neagh and so we get hit. We need protection and I thought we had it - but we didn’t.”

Ms Aiken has also asked for another exit to be created to allow emergency access to Riverside in the event of flooding.

The Six Mile Water Trust environmental group said it favours sustainable drainage (SUDS) as they are more environmentally friendly, ‘by using open swales, ponds, reed beds etc which favour wildlife, birds, insects and can create a pleasing visual aspect’.

Jim Gregg from the organisation said: “DFI Rivers agency has not embraced the environmental benefits and continues to use hard engineered systems, underground pipes, ducts, tanks and hydro brakes.

“The problem with these, is they also require maintenance as they will block with sediment and if contaminated will become septic time bombs and leach toxins into the receiving water course and do nothing to help the natural environs for wildlife and visual aesthetics.

“The Belmont Road development is not the main threat to Antrim town flooding - it starts much further up the catchment at Ballyclare, whereby all those additional homes add a significant increase in water volume entering the Six Mile Water, every drop of stormwater enters the river as well as treated sewage via the Waste Water Treatment Plant at Ballyclare.

“For example, average wastewater leaving a home is estimated to be 80/100 gallons per person per day, multiplied by the population living in Ballyclare, which amounts to a considerable amount of water that enters the Six Mile. Add to that is the draining of Hydepark Dam which did act as a natural attenuation during flash flood events and the increased development adjacent to the Ballymartin a major tributary of the Sixmile.

“These are issues that we as a Trust have raised with planners and were dismissed. You only have to look at the reason the Antrim town boardwalk development was cancelled. I am on record as stating Antrim Town will be renamed ‘Atlantis’.”

Back in 2018, David Magee, Building Director for Antrim Construction Company said: “As part of our planning application we have undertaken an extensive Environmental Impact Assessment and taken steps to mitigate for flooding and to protect habitats.

“Our proposed development is not within the one in 100 year flood plain, but we will invest £0.5 million in a flood attenuation system to ensure run-off from the river is slowed below natural green-field run-off rates to add protection to the river.”

At a launch event in Antrim’s Old Courthouse five years ago, the company presented their plans to local residents, insisting it had innovative plans to catch and store rainwater before releasing it slowly back into the river.

Back then, the Antrim Guardian said: “Initially part of the plans was an underground attenuation tank which would disperse water slowly back into the Six Mile in the event of heavy rain, but the firm is now exploring using a field bounding the site to build a lake and wildflower meadow instead.”

Ms Aiken added: “Public Consultation meetings prior to planning were held to explain that attenuation tanks were compulsory for Antrim Construction Company in order to meet Conditions of Planning as a vital part of flood prevention for Antrim.

“The original scheme of attenuation tank insertion needs to be enforced as a matter of great urgency rather than awaiting a new planning application.”

Since last week, Ms Aitken and Mr Gregg have met with the developers for an update and more on the story will follow next week.

The Antrim Guardian understands that Turley, agent for the developer, will be running a public consultation event at Belmont Hall early next month and that leaflets with a feedback form will be issued to properties in the vicinity.

It is understood that this event will take place at Belmont Hall on February 8.

A website and phoneline will also be set up.

Meanwhile, it is understood that Riverside residents also plan to object to plans for an ‘environmentally and economically sustainable’ social housing scheme for older people on Dublin Road, Antrim and accessed from Bridge Street.

Mainline Contracts has proposed a development of 48 units for active elderly residents (over 55), comprising 45 two-bed apartments and three one-bed apartments.