Waiakeakua Stream is a lesser known trail in the back of Mānoa Valley that leads to a couple of different waterfalls and pools along the river bed. The trail starts along the Pu'u Pia Trailhead and eventually makes a steep descent down an unmarked and slippery path to the valley floor. The trail then turns right along the stream, heading up an old staircase and along old water pipes. Hikers will pass by some deep river pools, and certain stream crossings can be high after the rain. Expect to get muddy and wet! The trail forks at the top of the first small waterfall, and the left fork snakes up the Mānoa middle ridge. The right fork continues along the stream, passing in and out of dense tropical forest plants. Here the trail can be difficult to follow at times because it is not consistently maintained. Keep following the river and reach another unmarked fork in the trail. This time the right fork leads uphill to a vertical waterfall. The left fork continues along the river, passing more pools and flumes. Toward the end of the trail, hikers will have to wade through the river and scramble up some boulders in the stream to reach a two-tiered waterfall that is usually flowing. The lack of ropes makes these falls a smart place to turn around, as ascending the slippery and loose rock can be quite dangerous. Follow the trail back the way you came, noting where to turn off at each junction, as following the stream too far down the valley will lead to the Seven Bridges, which is tresspassing on private property.
This hike is not to be underestimated. Pu'u Pia is a great family hike, but only experienced hikers should proceed to the valley floor. Be aware that changing weather conditions could cause flash flooding in the stream without warning. Respect the land and keep the trail clean and free of trash debris.