That “Dam” Clay Kellogg, Part 2

One Dam or Two?

After completing the Gila Bend project, as described in Part 1 of this series, Hiram Clay Kellogg’s dam-building skills were next put to use in Hawaii Territory. The design and construction of the Wahiawa Dam on Oahu in 1903-5 was probably his most significant achievement in the dam-building arena.

There is some contradictory information regarding this project, with a few sources implying or outright stating that Kellogg was construction engineer for two dams in Hawaii. There are three possible explanations for the confusion.

• Although officially named Wahiawa, the dam is also known as the Waialua for reasons that will become clear later in this article.
• It was constructed at a fork in the Kaukonahua River, backing the water up into two separate valleys to form what may have been considered two reservoirs, implying two separate dams.
• Kellogg was involved with another Hawaiian dam a bit later in his career, but in a different capacity, as we will see in Part 3 of this series.

By 1889 sugar cane had become a rapidly-developing crop on Oahu. Despite the fact that the Hawaiian Islands receive significant amounts of total rain, it falls sporadically onto volcanic soil that does little to hold it. For agricultural purposes, much of the terrain is practically desert unless the rainfall can be captured and held.

Initially the sugar plantations were dependent on irrigation systems that used massive pumps to lift rainwater up to 650 feet from artesian wells along the coast to the level of the plantations. This was a very expensive proposition and most likely required a great deal of maintenance. So the idea of building a dam became very attractive.

Leonard Grant (L. G.) Kellogg, one of Clay’s brothers, had settled in the colony of Wahiawa, which was primarily engaged in pineapple farming. He organized the Wahiawa Water Company with the purpose of providing drinking water and irrigation to the colony. The company constructed a ditch from a local water source to the colony.

In 1902, L. G. called in his mainland brother to survey the area as the site of a potential reservoir. He also turned to the Waialua Sugar Plantation to help finance a reservoir project and be a customer of the water after the dam was built.

Once the survey was completed, L. G. called on James Dix Schuyler, a prominent consulting engineer from Los Angeles. Schuyler recommended a dam structure that used a combination of rock fill (loose boulders packed together) and hydraulic fill (soil that is moved into place and compacted by water). Clay was hired to do the detailed plans for the dam and to supervise its construction.

Construction began in 1903 and was completed in 1905. The logistics of the construction were challenging. Railroad track was laid for bringing in the boulders for the rock fill portion from as far away as 6 miles. A high trestle was built over the dam site, and the rocks were dropped into place. The long drop compacted them so they held in place.

The hydraulic fill was an even bigger challenge. Normally, high pressure water is sprayed from pipes to wash the soil into place. But there was not enough water pressure available to do so. Worse, the volcanic soil was highly resistant to erosion and would not flow along like ordinary soil. Clay Kellogg needed to develop innovative methods on the fly to get the soil in place. These required a great deal of additional manpower, which was supplied by Japanese laborers working at wages of 8 cents per cubic yard of soil moved.

At its completion, it was the highest dam and largest reservoir in the Hawaiian Islands. The dam rose 98 feet above the stream bed, was 460 feet long and 25 feet wide at the crest, and 580 feet wide at the base. The original capacity of the reservoir was 2.5 billion gallons. It cost $300,000 to build, and was considered something of a bargain.

The dam is still in place today, although its reservoir, now known as Lake Wilson, is kept at a much smaller size and is used only for fishing and other recreation. Concerns over its age and gradual deterioration keep it under constant watch by safety authorities.

The size, prominence, and innovative qualities of the Wahiawa Dam led it to be included in at least two engineering textbooks, one written by James Dix Schuyler and the other by Edward Wegmann. (See sources below for full citations.)

The Kellogg collection at Heritage Museum of Orange County includes numerous items related to this project, including the photo used in this article and several copies of a printed prospectus for the project authored by Clay Kellogg.

Watch for the next installment of this series, in which Clay Kellogg returns to Hawaii as an engineering expert, tasked with resolving a politically-charged dispute over a leaking dam in Dam Politics.