There is no standard dimension for the width of ancient Hawaiian fishpond walls.

Some are as little as 6 to 8 feet wide at the base. A rare few are more than 20 feet wide at the base.

The wider walls tend to be found in areas faced by stormy seas, places where the strength of a sturdy, wide base is needed to protect the fishpond wall and the resources within.

Narrower walls are found where the water is calm and minimal strength is necessary. On a pond in which one side faces the prevailing seas and the other is more protected, the windward wall will often be wider.

In the national debriefing after Hurricane Katrina's breaching of the dikes in New Orleans, lots of folks are pointing fingers: "You knew a huge storm would break the dikes, so why didn't you spend the money to upgrade them?"

It may be a function of human nature that we don't act on the warning nearly as readily as we act on the actual catastrophe.

One assumes that Hawaiian pond builders lost some walls to storms before they began fortifying them.

Some national officials are pointing to the great dikes of the Netherlands. But even the Dutch didn't build their dikes to these standards without a powerful incentive. A storm in 1953 breached the existing dike system, costing the European nation nearly 2,000 lives.

It was after that storm that the Netherlands decided it could not rely on dikes that can survive only an average storm. They decided on a standard aimed at surviving not a 100-year storm, or a 1,000-year storm, but a 10,000-year event.

It's a heck of a standard and an expensive one. And now, in view of global sea level rise, a standard that will require further upgrading of dikes. They'll need to be higher and wider.

The Netherlands also has experience with a less technological solution. In some areas, they have protected dune lands extending a mile or more in from the shoreline, preventing development in the dunes. The dunes naturally protect low-lying inland areas from storms, and also serve as an important recreation area.

In Hawai'i, many of our coastal dunes have been flattened and developed, and the sand carted off. In many shoreline areas, properties have been built to within a few dozen feet of the vegetation line. Ultimately, it may be wiser to protect coastal environments — and to let them protect inland regions. The alternative may be vast, expensive, dikelike armored coastlines.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.