Today would be an "easy" day. Gene would take Jane, Stanka and me on a tour of the lower Makaha water tunnels. Like the ones in Wai`anae Valley they were dug/blasted by the now long defunked Wai`anae Sugar Plantation, most likely early in the 1900's. The source or our information on the tunnels comes from a book titled "Geology & Ground-Water Resources of the Island of Oahu", by Stearns & Vaksvik written in 1935.
I you get a USGS map of Makaha and look carefully you will find tunnels marked on both the left and right banks of the stream. According to Stearns there are 11 tunnels in Makaha although he only describes 10. What is interesting is that if you take GPS readings off the USGS map and then look for tunnels 1-4 you will not find them. Dan and I tried a few months ago and could not find them. Gene used Stearns descriptions and found them a few 1000 feet deeper into the valley. Here Stanka and Gene check the print outs as they stand in front of Tunnel 1. It is only about 30 deep, but in January of 1932 it was discharging about 3000 gallons a day.
The entrance to Tunnel 1.