In a submission to the NSW Heritage Council, the council's general manager David Farmer said a proposal to add Wollongong Harbour to the State Heritage Register could delay a number of yet-to-be completed Blue Mile projects - several of which were partially funded by state and federal grants and must be completed under tight time frames.

A council spokeswoman told the Mercury the heritage listing would add a separate approval process to many of the works, which meant "funding allocated to these projects, either through grants or council's budget, may not be spent in time."

While supporting the Heritage Council's listing of the harbour precinct, Mr Farmer urged it to grant several "site specific exemptions", arguing the Blue Mile projects had already been subject to the council's "rigorous internal heritage assessment process."

Works that risk being delayed include a concrete footpath along Cliff Rd connecting North Beach to Belmore Basin, to which the Federal Government contributed $2.9 million, and a cliff-top walk along the southern corner of Flagstaff Hill that received a $275,000 state grant.

Both projects are midway through construction.

Mr Farmer also expressed concern about the roll-out of the Flagstaff Hill heritage trail, work on which was expected to proceed this winter.

A heritage listing could push construction into the peak summer period and force the council to wait another year before starting the work, he said.

The submission also requested exemptions to permit special events such as New Year's Eve and Australia Day celebrations and allow for ongoing maintenance along the foreshore.

The submission acknowledged the potential of the heritage listing to attract extra visitors to the harbour and noted the new funding opportunities it would bring.