About six months ago I convinced my wife to join me on a hike to these pools and falls. She did not want to go at all, having been before and having arrived to a non-existent waterfall and nasty looking pools. She finally agreed to go with me and we set out for the short hike. We arrived to the Pacific Palisades subdivision and the start, somewhere around noon. We walked up the street and passed through the gate and down the dirt road. Near the end of the road we reached a water tank and kept going straight. My wife and I had both been on this trail numerous of times before and to our delight this was by far the best weather that we had ever experienced on this hike. We were just keeping our fingers crossed that the falls would be going and that the pool would be nice, so we could swim, being that it was a scorcher of a day. From what I remember the trail was very discernible and easy to follow. We stayed on the most obvious trail and eventually veered right and headed down into Waimano Valley. If we had continued straight we would have ended up on the Manana Ridge trail. I appologize for the crappy directions but I will add this to my list of hikes that I need to go back to and update with accurate and pinpoint directions (do check out the hikers guide to oahu by stuart ball for good directions and if you google waimano pool and falls, someone should have better directions for the first part of this hike).
Once taking the right and heading towards Waimano valley, we hit a massive hill, covered with banyan tree roots. This is "cardiac hill". Due to the insane steepness of this hill and the muddiness the usually comes along with the area, the walk down is slow and we found ourselves walking sideways most of the time. The trip back up this hill is not much better, and it is correctly deemed "cardiac hill". Once at the bottom of this hill, we took a left and followed the muddy trail downwards until we reached a few ropes to help us descend and then we veered right and crossed a stream onto a once again muddy trail. From here the trail was insanely easy for us to follow. We passed a couple of tiny rockfaces, slowly climbing down each, and then we finally reached a junction in which we turned left and shortly thereafter we reached the falls. I found that once we were in Waimano Valley, all of the major junctions were left hand turns, so as long as one remembers that, they shouldn't get lost once they are in the valley.
Once at the falls, we put our stuff down and took a tiny trail heading up to the big watefall. Getting down to it can be a little tricky, but there are ropes to help in the descent, but it requires going down a small but vertical rockface. Not the toughest thing in the world, but not the easiest either. Once down we hung out at the waterfall, taking pictures and taking a dip in the water. We then climbed down to a miniature waterfall and jumped off the rocks into the beautiful, deep swimming hole below us. We swam around and talked story for quite some time with the other folks who were hanging out at the falls on this day too. This place gets pretty packed on the weekends and you'll see a lot of locals jumping from the higher cliffs above. Be careful if you decide to attempt this. All in all this a great hike for a nice sunny winter day here in Oahu. If deciding to venture back to the falls in the summer, make sure it has rained a good amount lately, or you just might arrive at a stream with stagnant water and no waterfall.
Directions: From H-1, exit at the Pearl City/Waimalu exit. Turn right on Moanalua Road at the end of the ramp. As Moanalua Road ends, turn right on Waimano Home Road. Turn left onto Komo Mai Drive, driving through Pacific Palisades to the end of the road. A locked gate restricts vehicular traffic beyond this point. Park here, and proceed on foot through the pedestrian passageway adjacent of the gate. The road becomes the trail just past the water tank. (Driving directions are from ehawaii.gov)
The big waterfall after a period of very little rain
The big waterfall after some decent rain
The big waterfall after a torrential downpour
The deep swimming hole. Probably at least ten feet deep in the middle.