In a letter to Mr Guterres and the UN Security Council, released on Thursday, Syria's Deputy UN Ambassador Mounzer Mounzer wrote that residents along the Euphrates River in Iraq could also be affected by the "systematic sabotage of infrastructure."
"The total destruction of these dams that are being targeted by the air strikes will wash away and flood cities, towns and villages, endangering the lives of hundreds of thousands of people living in those areas," Mr Mounzer wrote.
The international coalition and the Pentagon were not immediately available for comment. The US-led coalition has been carrying out air strikes in Syria against ISIS terrorists since September 2014.
The United Nations last month warned of catastrophic flooding in Syria from the Euphrates dam, which is at risk from high water levels, sabotage by Islamic State and further damage from air strikes by the coalition.
The Russian-backed Syrian army has advanced rapidly in recent weeks to the western banks of the Euphrates River.
Syrian President Bashar al-Assad, in an interview broadcast on Saturday, called US forces in the country "invaders" as they were not there with the government's permission.