More than 90 percent of Hawaii's dams are considered "high hazard" dams, which means if they fail it could result in the loss of life.
The state Department of Land and Natural Resources says many of Hawaii's dams were recently classified at that level because of the increase in development with more communities being built downstream.
The state and its partners say there are many challenges when it comes to inspecting all 132 state dams, such as limited manpower, limited funding, and cooperation from the community.
The Board of Water Supply, which has managed the Nuuanu Reservoir for decades, joined DLNR inspectors on Thursday to check the structural safety of the dam and the growth of the surrounding vegetation.
"This dam has never flooded. When we had the 40 days of rain, it never even got remotely close to the top and we absolutely had no problems with that," said Kathleen Pahinui, BWS information officer.
DLNR says it's required to inspect each reservoir and dam every five years, but after receiving part of the blame for the tragic 2006 Kaloko Dam break that left seven people dead, it says it tries to hold inspections every two years.
The state also encourages private dam owners and operators like BWS to conduct their own routine inspections.
"We have pipes that monitor the water levels and we can also monitor them remotely from several computers back at BWS main offices. But we're very religious about watching and making sure the levels of the dam stay under any need for concern," said Pahinui.
While every high hazard dam owner is required to have an Emergency Action Plan with DLNR, the department says not all of them currently do.
There are also challenges with trespassing.
Nuuanu Reservoir is located near the Lulumahu falls trail and hikers can often be seen walking on private property. Signs that say "No diving or jumping" are posted.
"It is a structure. It is an area being kept for stormwater control to prevent flooding and to manage stormwater when we do have heavy rains so its not a playground and not for recreation," said Pahinui.