The developer hoping to build a five-storey block of 53 apartments next to Booterstown Bird Sanctuary in Dublin Bay says the development would be a "gain gain situation" for nature and residents.
Mr David Jameson, co-director of Ashcastle Developments Ltd, added that if planning permission was not granted "there are other options, but people can rest assured, something will be built on that site".
A decision on his company's application for planning permission to construct apartments, a car park and a public park is due from Dublin City Council and Dún Laoghaire-Rathdown County Council on June 2nd.
The four-acre coastal site adjacent to the bird sanctuary straddles the border between the two authorities.
While the application with Dún Laoghaire-Rathdown is for the development of a public park with 14 parking spaces, that with Dublin City Council is for 53 apartments "in five interconnecting blocks ranging in height from three-storey plus penthouse to five-storey plus penthouse" with more than 100 parking spaces.
Among over 80 objectors to the plans is An Taisce. It says the site is zoned as an amenity area, that the development would be too big, that it would have an adverse visual impact and that it would have a negative impact on the marsh.
Mr Oran O'Sullivan, general manager of Birdwatch Ireland, said he would have concerns about the "disturbance factor" to birds.
He said kingfishers, redshank, snipe, herons and in recent years egrets and Brent geese were regularly seen there.
Mr Jameson, however, says the development will do the birds no harm. He insists his company's plans will turn the site, now overgrown with scrub, into a high quality amenity.
"We have done a full Environmental Impact Statement, looking at the ecology, archeology, visuals. The plans will involve landscaping the site and then ceding 70 per cent of it to the local authorities as a public park. The authorities don't want it in its current state."
He says under the overgrowth there are rare Pyramidal orchids which will "die out" on the site if it is not taken in hand.
He said the proposed apartment blocks would face the marsh rather than the sea. "So it's only the gable end that people will see face-on from the Rock Road."
He said concerns about possible disturbance to nearby wildlife amounted to a "very tenuous argument".
"If you look at the number of articulated lorries, cars and motorbikes trundling by every day on one side, and the DART on the other, arguing 53 apartments is going to cause more disturbance than that is ridiculous."
He also said the apartments would be sited as far away from the marsh as possible, and they would be "very high quality".
"This is an opportunity for everyone to put the issue of this site and what's going to happen with it to bed for ever. I hope the planners give it a fair consideration. The site is an amenity site, but it's zoned with Z9 status, so residential use can be considered.
"If these plans are accepted the public will get a beautiful amenity and unobtrusive building.
