THE PROPOSED WYNN RESORTS hotel and casino in Everett will feature just 10 slips for boats to pull up and dock. The number seems small given all the concerns about automobile traffic congestion at the resort, but Wynn Resorts officials said they think the number should be sufficient.

The number of boat slips became something of an issue on Thursday at a hearing challenging the state Department of Environmental Protection’s award of a permit to Wynn Resorts to build its facility on tidelands along the Mystic River. The challenge by Somerville has stopped construction of the gambling resort in its tracks, and led to some bad blood between Somerville Mayor Joseph Curtatone and Wynn Resorts chief Steve Wynn.

One of Somerville’s witnesses, marine surveyor Thomas Hill, testified that boaters would flock to the resort and could present problems for law enforcement officials patrolling the Mystic River. “Boaters are a curious lot,” he said.

But Wynn Resorts lawyers said traffic congestion was unlikely because there will only be 10 boat slips at the resort. They said boats, including water taxis operated by Wynn Resorts,  will be able to pull up and drop off passengers, but only 10 boats will be able to park at any given time. All other boats will be turned away.

Another Somerville witness, consultant Robert Golledge, a former commissioner of the Department of Environmental Protection from 2003 to 2006, said he felt regulators should have demanded more mitigation measures from Wynn Resorts in return for a permit lasting 85 years.

Hearing officer Jane Rothchild said she will make a recommendation to Martin Suuberg, the current commissioner of the Department of Environmental Protection, who will make the final ruling on the permit appeal. A decision is expected this summer.