Otter activity at a Co Armagh lake could be harmed by building a new £45 million college campus on its shoreline, the High Court was told.
Lawyers for a grandmother who lives close to the parkland site claimed it is currently used by the aquatic mammals with European protected species.
Clare McCann, 65, is challenging the decision to grant planning permission for the new Southern Regional College at the south lake in Craigavon.
Armagh Banbridge and Craigavon Borough Council gave the project the green light in January 2019.
Campaigners opposed to the campus being built in the area claim it will reduce green space in a public park, and lead to an annual influx of thousands of students.
Mrs McCann is seeking a judicial review amid concerns about the impact on wildlife and residents.
Her legal team contend that the planning approval was irrational and breached legal requirements.
They also allege that the council failed to assess the impact on protected species, including otters, and did not carry out the proper habitats regulations assessment.
Based on local knowledge of otter activity in the area, they insisted that it was wrong to conclude the development will not cause harm.
Opening proceedings for Mrs McCann, barrister David Scoffield QC said his client now brings her grandchildren to the park she has enjoyed for decades.
"It has a number of special memories for her, it's an important feature in her life," counsel said.
"She enjoys the water and wildlife which is there, she is aware of otters in the lake."
In a case set to last for three days, Mr Justice Huddleston will also hear challenges to the planning policy and alleged breach of statutory duty.
Outside court Mrs McCann and her solicitor, Claire McKeegan, claimed the land should never have been considered for a new college.
"It's going to be devastating for me if its built," the grandmother said.
"When we discovered there were otters there it brought us such excitement. They are so endangered and they have to be protected."
Kelly Laverty of campaign group Save Craigavon Park and Lakes further claimed development will impact on an area scarred by deprivation and suicide rates.
She added: "If you were to put Belfast Metropolitan College in the middle of Ormeau Park there would be uproar. This is exactly the same."