Leon Sollenburger has worked with soil for decades. From Pearl Harbor to the North Shore, he’s worked on everything from the former Del Monte lands in Kunia to the former Dole lands north of Wahiawā and yes—Ho‘opili too.
So respected is Sollenburger’s opinion on soil that he was appointed to the advisory committee for Important Ag Land (IAL) designation on O‘ahu. IAL designation protects agricultural land from being converted to other land use designations. In the 1970s the State began to require each county to designate its IALs. None of the counties has ever complied with that rule, including Honolulu county, until now. On O‘ahu, we are finally in the process of designating these IALs. If it were up to Sollenburger, Ho‘opili would be priority one for IAL protection in Honolulu county, but unfortunately it isn’t up to him.
“The first night the advisory committee met we were informed, in no uncertain terms, that no land within the Urban Growth Boundary (UGB) would be considered for IAL,” says Sollenburger. “That specifically excludes Ho‘oplili. So, when you hear that Ho‘opili is not ‘Important Agricultural Land,’ that’s the reason why.”

A place like no other in the State
There’s no doubt that Ho‘opili is important ag land, even if it isn’t IAL.
“I personally think that this is some of the most productive agricultural land in the State and if there’s any piece of ground that ought to be designated as Important Agricultural Land, it should be this piece,” says Sollenburger. “But it is not eligible for consideration.”
So what makes Ho‘opili such a unique place?
“There are lots of places on O‘ahu that have good, level soils,” says Sollenburger. “There are lots of places on O‘ahu that have water. There are lots of places on O‘ahu where various crops will grow. Ho‘opili is unique because it has a combination of those factors that no other place on O‘ahu, and really very few other places in the entire state, can put together in one package.”
1. Ho‘opili is flat. It’s easy to work with large equipment on and most of the land there can be put in to production of agriculture.
2. This is a part of the island with very little cloud cover. In the list of requirements to grow a crop, sunshine is right there at the top. However, this does mean that irrigation will be required for Ho‘opili.
3. Water is the next ingredient. While it’s true that rainfall is lower here than it needs to be, the water table at Ho‘opili is not all that deep. Therefore a supply of good quality clean water can be put into use here at a reasonable cost through wells which wouldn’t need to be all that deep.
4. There is one more factor to consider, and it’s a factor that Ho‘opili beats nearly every other piece of agricultural land in Oahu on: Its proximity to the markets. The Wai‘anae coast, the North Shore and Waimānalo are all much farther away from Honolulu. Farmers in these areas have to factor in the cost of transportation, gas and time stuck in traffic (which is time away from making the fields productive).
“Let me repeat something I said to the Land Use Commission,” says Sollenburger. “If we have the most fertile soil we could ever ask for, abundant water, but we don’t have sunshine, we’re not going to get a good crop. You can’t compensate for the lack of sunshine by adding more nitrogen fertilizer. You can’t compensate for lack of nitrogen by adding more water. None of those things will substitute for the other. You have to have the whole package and Ho‘opili represents that whole package.”
Currently there is a PR campaign underway on the part of the landowners, D.R. Horton-Schuler, to convince us that part of Ho‘opili will be set aside for agriculture.
“If you look at the map, the areas that are being designated for ag-use in Ho‘opili are the gulches,” says Sollenburger. “These areas are not suitable for agriculture and setting them aside as such is really a sham.”
These areas are too steep to drive a tractor on. At the bottom of the gulches, where it’s flat again, you encounter rock, not soil. The only way to grow plants in the gulches would be with terracing, or green housing or some other hydroponics system that would control light and water levels and keep them adequate (all of which are expensive choices).
“That’s not really agriculture, and it’s certainly not cost-effective when you compare that to open field production,” says Sollenburger.

Water concerns
Every single piece of land that was proposed as replacement ag-land for Ho‘opili during the Land Use Commission’s hearings is at a higher elevation, has higher cloud cover and, in most cases, has less available high-quality water.
Practically every piece of ag-land from Wahiawā to the North Shore is irrigated with water from Lake Wilson. Lake Wilson is an artificial lake outside Wahiawā that captures water from two streams that come out of the mountains.
“It would be good, clean water, except for one thing,” says Sollenburger. “The Wahiawā waste-water treatment plant discharges its effluent into the lake.”
That effluent is classified as R2, a category of waste-water that is acceptable for certain forms of agriculture, but has restrictions on what it can be used for. It can be used to grow plants as long as the part of the plant that is used or consumed does not come in contact with the water.
“For example, you can use it to grow banana trees or sweet corn,” says Sollenburger. “In either case the water is applied to the ground while the harvested part of the plant grows above ground. You could not use it to grow potatoes, carrots, onions or anything that grows below ground.”
Any water supply that has any part of it contributed from an R2 source renders the entire water supply R2. From Wahiawā to Hale‘iwa—all that land is watered by Lake Wilson and therefore considered off limits to many different kinds of vegetable and fruit production.
Ho‘opili has clean ground water that can be extracted cheaply. Ho‘opili has tons of sunshine year-round. And for a farmer working in irrigated fields, that’s a huge advantage. In other places, even Kunia, during the winter the rainfall can be sufficient to make it almost impossible to farm those fields for weeks or even months at a time.
“I don’t care who farms it. I don’t care what they grow on it either. That doesn’t really matter,” says Sollenburger. “What matters is this: A productive piece of soil, with water and infrastructure, has the potential to grow just about anything. And in years to come, that potential is what we need to save. If that potential is gone, it is gone and you’ll never get it back.”