Nevada State Engineer Adam Sullivan, who is responsible for managing water usage and resources in the driest state in the country, has abruptly left the role.

Jenny Jackson, a spokesperson for the Nevada Department of Conservation and Natural Resources (DCNR), said in a statement Friday that Sullivan, who was also administrator for the Division of Water Resources, is "no longer serving," but did not answer questions about what drove Sullivan's unexpected departure.

"DCNR is very appreciative of Adam's service and wishes him well in his future endeavors," Jackson wrote. "The Department is now focused on strengthening Nevada's water management and ensuring a smooth leadership transition."

Former deputy administrator Chris Thorson is the new acting administrator for the Division of Water Resources.

The departure is unusual given that the state engineer often serves under multiple governors; the role requires expertise in complicated water laws and typically ends in retirement. 

Sullivan, who was appointed state engineer in July 2021 by then-Gov. Steve Sisolak (D), replaced the previous engineer, Tim Wilson, who retired after working for the state for 25 years. 

Previously, Sullivan had worked in the area of water resources for more than two decades and at the Division of Water Resources since 2009. He was best known for his involvement in court cases that led to a landmark state Supreme Court decision that established a precedent for the state to manage groundwater along with surface water and recognized the interconnectedness of groundwater systems.

The court fights demonstrate the enormous pushback the state engineer's decisions face from developers and other entities that want expanded access to water in Nevada.

Asked about ongoing litigation and the plans for the division, Jackson said in a text message that the division is "fully operational" and work will continue as usual.

Sullivan declined a request to comment.