A lengthy and complex shoreline-protection plan under review in Washington state would ban new covered moorages and boat houses and force significant and costly changes in some existing waterfront structures. Some facilities unable to comply likely will disappear.

The state’s goal is to protect and enhance the shoreline by encouraging the growth of 29 species of sea grasses and small fish and other marine life that thrive along natural shorelines and which are part of the food chain of larger fish, such as salmon, seals and orcas, said Peter Goldmark, the state’s commissioner of public lands.

Existing covered marinas eventually would be required to replace portions of solid rooftops with translucent panels to increase the amount of light falling on the water. Walkways in marinas – now usually concrete or wood – would be replaced with grated walks, again to let sunlight reach the water. Creosoted timbers, used as piling in moorings and in breakwaters, would be replaced with concrete or steel components.

The regulations have been drafted by the state’s Department of Natural Resouces (DNR), which manages 2.6 million acres of waterfront lands in the state. That includes lakes, rivers and tidal waters. About 4,000 businesses, marinas, boat yards, individuals and tribal groups occupy approximately 12,000 acres of shoreline under state leases and would be affected by the proposed regulations.

Public comments will be accepted until December 4; the department expects to adopt shoreline habitat-protection regulations next spring after reviewing comments.

The department’s Aquatic Lands Habitat Conservation Plan has been years in the making and focuses on shoreline deemed threatened or endangered under the federal Endangered Species Act. The state agency said its work has undergone significant scientific review, beginning in 2006.

Marinas, boat repair yards and other waterfront structures on or over DNR shoreline operate under 30-year leases with the state. Under the new regulations operating conditions and construction standards would become terms of leases and applicants will be required to meet new standards within 20 years or as conditions of lease renewal.

“For existing uses, changes do not need to happen now or all at once,” DNR said. “It is okay to develop a plan to spread changes out over the length of the lease.”