You don't know what you've got till it's gone — or at least very expensive.

That variation on a song lyric applies universally, but it's especially true in a consumer society like America, where we are accustomed to living in a land of plenty. It took $3 gallons of gas, drawing close to that $4 mark, to shake us up. Hawai'i felt the same squeeze, and the collective panic pushed the state to adopt an energy initiative aimed at stemming our fossil-fuels appetite.

The same sense of urgency is lacking, however, in our use of electricity and water, two other critical needs whose importance becomes clearest when they're in short supply.

Recurrences of blackouts such as the ones that peppered O'ahu recently are likely as summer heat drives up our hunger for air conditioning, and long showers and water-sprinkler indulgences will be sought to cool things down for our lawns and ourselves.

The fact is, the more houses are built, the more our collective usage of power and water will rise. That's why people — led by their state and city government authorities — must encourage a broader conservation ethic, and not only at times when a shortage is apparent.

To some extent, a change in the culture is already beginning. Hawaiian Electric Co. has been pursuing the use of renewable-energy sources for its power grid, though probably not at the pace that environmental and public-interest groups would like to see.

Both the power and water utilities have disincentives for wasteful practices built into billing schemes, and encourage conservation in other ways. But government could play a larger role in seeing that conservation is practiced as a matter of course.

For example, while public buildings are being retrofitted for greater energy efficiency, water efficiency should be part of the review as well. Have water-conserving plumbing fixtures been installed?

Some private, large-scale users, such as hotels, have been taking similar steps on their own, but more should be done to encourage them.

The state and counties should lead by example.