Along what used to be a lakeshore boulevard, worn-down snack bars and dressing rooms are testament to the days when people from across Iran would come to water-ski on the lake or cover themselves in its black mud, which is said to have healing powers.

About two decades ago, a local villager, Mokhtar Cheraghi, began to notice the water line receding. “First a hundred meters, then two hundred meters. After a while, we couldn’t see the shoreline anymore,” he said, standing in what was once his thriving cafe, Cheraghi’s Beach. “We kept waiting for the water to return, but it never did.”

Most people in the area blame the half-dozen major dams the government has built in the region for the lake’s disappearance. The dams have greatly reduced the flow of water in the 11 rivers that feed into the lake. As an arid country with numerous lofty mountain chains, Iran has a predilection for dams that extends to the reign of Shah Mohammed Reza Pahlavi.

Dam construction was given renewed emphasis under Mr. Rouhani’s predecessor as president, Mahmoud Ahmadinejad, who as an engineer had a weakness for grand projects. Another driving force is the Islamic Revolutionary Guards Corps, which through its engineering arm, Khatam al-Anbia Construction, builds many of the dams in Iran and surrounding countries.

Half an hour’s drive into the mountains above the city of Urmia stands the mighty Chahchai Dam, collecting water that would otherwise have reached the lake. The dam, finished during Mr. Ahmadinejad’s first term, now holds a huge lake itself, which local farmers use for irrigating their lands.

“Some of Urmia’s water is here,” said Mr. Ranaghadr, raising his voice over the howling winds that blow down from the surrounding snowcapped peaks. “The people here need water, too, is what they say.”