Denverites planning a trip to the zoo should check the calendar before heading out during the next month.

Denver Zoo Conservation Alliance said it will be closed on nine select dates between Feb. 18 and March 5 as it replaces an aging water main.

Denver Zoo said the closures will take place on Feb. 18-20, 25-26 and March 3-5. The closures will not impact weekends.

“This critical improvement is made possible by $3.2 million in funding from the City and County of Denver to improve our water infrastructure and prevent future leaks and losses and make even more progress towards our ambition sustainability goals,” zoo officials said in a post on its website.

The zoo estimates the current water main is more than 50 years old.

Zoo officials said they would also be working on other projects to enhance the visitor experience, such as upgrading pathways, during the closures.