The sea level is rising fast, and destructive storms are occurring more frequently, said Williams, who expects things to get even worse.
He and other shoreline advocates say the state should consider how to protect coastal areas from furious storms when they rebuild it, such as relocating homes and businesses farther from the shore, building more seawalls and keeping sand dunes high.
How to rebuild after the disaster is becoming an issue even as New Jersey assesses its damage.
The state's death toll from Sandy climbed to at least 14 while 1.7 million customers remained without electricity Thursday and earth-moving equipment made its way for the first time to hard-hit barrier island communities.
In some coastal towns, residents were getting their first look at the damage, but they were being barred from checking out their property on barrier islands.
Most passenger trains were still suspended and lines were long at gas pumps across the state. But there were some steps toward normalcy: State government offices and many schools reopened Thursday, and most New Jersey Transit bus routes resumed service.
The state's main focus was at the storied Jersey Shore, where houses were thrown from their foundations and parks and beaches were in ruins.
In his evening briefing Wednesday, Gov. Chris Christie reiterated that he wants to rebuild.
"I don't believe in a state like ours, where the Jersey Shore is such a part of life, that you just pick up and walk away," he said.
But the governor said homeowners in hard-hit areas should decide for themselves whether they want to rebuild or sell their property to the state for conservation. New Jersey has a program to buy flood-prone homes, but it's mostly been used for inland flood plains, not the shore.
The government, the Republican governor said, should not decide where rebuilding is and isn't allowed. On Thursday, state Department of Environmental Protection spokesman Larry Hajna said he expects building standards to be updated, as they have been after other major storms.
New York Gov. Andrew Cuomo, a Democrat, disagreed with Christie, saying that rebuilding after Sandy should include new ways to prevent damage from future hurricanes and storms.
Shoreline advocates say there are three ways to protect the shore from extreme weather: build more jetties and seawalls, keep beaches replenished and relocate homes and businesses.
The physical solutions can help protect homes and roads but also cut off access to the beaches or water. New Jersey is known for having a lot of protective barriers.
The U.S. Army Corps of Engineers says it's also moved more than 65 million cubic yards of sand for replenishment projects in New Jersey. The state government has done additional projects without federal assistance.
Environmentalists say moving sand can cause harm to the areas it's moved from and might not be a good match for its new location. The supply of usable sand also is limited, they say.
"It's like a bad drug habit," said Chad Nelsen, the environmental director of the Surfrider Foundation, a national organization dedicated to preserving beaches and oceans. "Once you start, you can't stop."
Still, it seems to work. Some residents on Long Beach Island on Wednesday credited high dunes and wide beaches built as part of replenishment efforts there for keeping destruction from being even worse.
The northern barrier island that suffered the worst damage from Sandy is the longest developed stretch of New Jersey's 127-mile coastline without the help of federal replenishment projects.
The federal government pays for much of the beach protection programs. Including state and local contributions, shore protection programs with federal involvement from Manasquan to Cape May have cost taxpayers $475 million since 1988. The state has a $25 million-per-year beach protection fund, much of which goes toward the federal projects, but some goes to other measures.
Peter Kasabach, executive director of the planning advocacy group New Jersey Future, says subsidies that encourage rebuilding as things were, including federal flood insurance, are problematic.
"We've built in places that we shouldn't have built and now those places are becoming even more hazardous and more expensive to stay in," he said. "As we grow and develop, we should make sure we don't continue to invest in those places."
He suggested bans on building in some sensitive beach areas, or requirements that homes be built farther from the ocean.
The Surfrider Foundation's Nelsen said he hopes that New Jersey communities at least consider rebuilding in different places, which he said has never been done on a large scale in a U.S. oceanfront.
"We're about to spend some ungodly sum of money to restore the coast," he said. "Let's make sure we spent it wisely."
Mulvihill reported from Trenton, N.J. Associated Press writer Wayne Parry in Mantoloking contributed to this report.