Project officer Cathie Kelly, 59, told a court how she fell as she tried to make it back to the safety of her office.
She sued the owners of the building - an old Victorian school in Greenock - claiming they did not take sufficient care for her safety.
The Court of Session in Edinburgh heard how a nearby rubbish dump was a magnet for gulls which nested on the roof of the old school and became aggressive when they had chicks.
Judge Paul Arthurson QC has heard of dashes in and out of the Pottery Street building using umbrellas and how garages in the vicinity fly helium balloons to protect their cars from droppings.
Previously there had been patrols using owls and hawks to try to get rid of the menace but these had stopped, claimed Mrs Kelly of Hyndland, Glasgow.
In a written ruling issued yesterday Judge Arthurson said: "I was particularly impressed with the evidence and demeanour of Mrs Kelly as she described the incident.
"This must have been truly terrifying for her."