On August 4th of 2013 I went in to place new caches at new locations and low and behold the two "missing" caches were right were they should be. Since I packed in 3 replacements and found two that were already there, now there are 5 along the ditch trail. And so we now have the Waimalu Ditch Quinter. As you walk in along the trail ALL 5 caches will be on your right. The trail to the cache was cleared by the Hawaiian Trail and Mountain Club on August 4th, 2013 and gets cleared once a year by said club.
In reality there is a 6th cache MUCH DEEPER in the valley. Check it out w/this ID number. GCZ0W5
Sometime around 1912 workers for the plantation in this area completed the McCandless Ditch to supply irrigation water to their sugar cane fields. The name McCandless Ditch really is inaccurate. It is really a system of tunnels with a few open ditches now and then. I’ll post a link to a map. What is amazing to me is that the tunnels run sort of parallel to the stream from a dam way back in the valley to a reservoir somewhere in the area of the Kaonohi Playground. Every once in a while they would blast a side tunnel to the stream side of the main tunnel so they could get rid of the rock they were blasting to make the main tunnel. These side tunnels were later “bricked” up so the water would not escape and flow down to the stream. The Ditch/Tunnel system is approximately 3.2 miles long; again most of this is tunnel not open ditch.
Park on Onikiniki, which is at the high end of Kaohohi St in Aiea. Watch the No Parking signs or you'll get a ticket or worse get towed. If you are starting early in the morning, which is a good idea if you are going to do all the caches as it could take up to 6 hours round trip and you don't want to be there after dark, please be quite and don't disturb the neighborhood. Walk toward the gate. When you get just about to the wall you'll see a steep/muddy trail going down. GOOD LUCK! The trail is only steep until you reach the "ditch trail". From then the walk to this cache mostly level w/some ups and downs. The ground gets more difficult to walk on after crossing Small Waimalu Stream. Be careful as there are places w/a BIG DROP on your left in many places on the way in and on your right on the way out.
Now on to cache #4. Keep going past #3 and BEFORE you reach the bamboo patch your GPS should show you were to look. This cache is very much like #3 as it's inside the tunnel. Again beware of the low over hang and PLEASE be sure to hang the cache OUT OF SIGHT. And don't drop it over the wall, PLEASE.