President Donald Trump is facing a water hazard that threatens to swamp his ambitious renovation plan for a Washington golf course: the Potomac River.

Trump, an avid golfer who’s been widely accused of cheating at the game, said on social media last month that construction work will begin September 1 to turn the East Potomac Golf Links into “one of the Greatest Golf Courses anywhere in the World.”

But the popular 18-hole public course sits on an artificial island that was created in the late 1800s and has since sunk at least five feet into the surrounding river, according to Mother Jones magazine.

“The island is sinking,” said Rebecca Miller of the non-profit DC Preservation League, which is suing to block the project. “It's made of fill dirt, and the waters are rising.”

Ed Stierli of the National Parks Conservation Association, a non-profit advocacy group, also told Mother Jones that when he saw the renderings of Trump's plan, “One of the first questions I had was: Are they completely ignoring the landscape here?”

“Unfortunately, what’s moving forward here is almost a replica of the type of thinking we’re seeing with the Reflecting Pool: An administration ignoring climate, ignoring science, ignoring the Park Service’s own plans,” he said.

Trump’s infamous $16 million renovation of the Reflecting Pool, which included coating its basin with “American flag blue” sealant, led to algae growth that turned its water bright green and peeling paint that federal prosecutors have acknowledged was the result of a “botched” job by the contractor.

A spokesperson for the National Park Service didn't immediately return a Wednesday inquiry from The Independent, but the White House said Trump had “built some of the greatest golf courses in the world” during his career as a developer.

“The President and his extraordinary team will redevelop this decrepit golf course in our nation’s capital to restore its glamour and prestige,” White House spokesman Taylor Rogers said in a prepared statement.

The project is the latest in a string of efforts by Trump to remake Washington to his personal taste.

They include demolishing the East Wing of the White House to make way for a massive, gilded ballroom and bunker, with toxic debris from the site dumped on the golf course grounds, according to testing conducted for the National Park Service.

Trump also wants to build a 250-foot “triumphal arch” near Arlington National Cemetery and a National Garden of Heroes with statues of 50 notable Americans.

In addition to the construction projects, Tuesday marked the first anniversary of Trump's deployment of armed National Guard troops to Washington, which is costing taxpayers an estimated $3 million a day and will continue through Inauguration Day 2029, according to NPR.

Trump hasn't disclosed the cost or funding source for his golf course plan, but a May report by Golf Digest said that just rebuilding an island seawall could cost more than $600 million.

The Trump administration took control of the course on January 1 by cancelling a 50-year lease held by the non-profit National Links Trust, which struck a deal to run Washington's three municipal golf courses during Trump’s first term.

The East Potomac course was shut down for renovations in May, but a federal judge ordered it reopened, leading to an agreement between the National Links Trust and Trump's administration that will allow the president's plan to proceed, according to Golf Digest.