HONOLULU — A Honolulu city agency has proposed removing the popular Haiku Stairs hiking staircase that spans Oahu island's Koolau Mountains.

The Honolulu Board of Water Supply said it could cost about $1 million to remove the staircase with 3,922 steps that attracts 4,000 people yearly, The Honolulu Star-Advertiser reported Tuesday.

While it is extremely popular, the access that the staircase allows has been a cause of injuries and costly rescues of hikers, officials said.

Work to remove the stairs along the side of the Koolau Mountains in Kaneohe could begin next year and finish in mid-2022, officials said.

The water board owns most of the property where the stairs are located and said it spends $250,000 a year trying to deter trespassers from using them.

"Managing Haiku Stairs draws BWS staff, financial, and other resources away from our core mission to efficiently and effectively meet the water demand of our customers," said Ernest Lau, the agency's manager.

The agency cited safety and potential liability concerns due to the poor condition of the staircase's lower half.

The city spent $875,000 refurbishing the staircase in 2002 in anticipation of a land transfer from the Coast Guard, which ended public stair use in 1987. But the exchange was not completed and the climb remains an illegal adventure.

Honolulu's Democratic Mayor Kirk Caldwell said he would like the parks and recreation department to take possession, while also noting the need to "ensure the experience is made safer for hikers and first responders."