Is growth over?

Scaled-down developments that clear the water-supply hurdle must still meet tough new water-use standards. For instance, don't expect new homes to be built along the fairways of a new golf course or the shores of a man-made lake. The appliances in the new homes will be low-flow, and the pavement outside permeable to help replenish groundwater. State legislation that would have required developers to utilize all feasible water-efficiency measures in new construction and carry out other conservation measures in the surrounding community didn't pass earlier this year, but it undoubtedly will be back. Meanwhile, the Legislature is considering a requirement that all urban water agencies reduce their consumption by 20% within 12 years.

Agriculture, which consumes two-thirds of the delivered water in the state and remains a huge component of the California economy, is also feeling the sting of dwindling water supplies. Beginning with the MWD's reduction in water supplies, agencies throughout the state are pressing farmers to cut their water consumption by not growing water-intensive crops, investing in more efficient irrigation systems and even taking land out of agricultural use altogether. Pending state legislation would establish agricultural water conservation requirements.

The entire state economy ultimately will be affected by the water crisis. Yet it is unrealistic to expect that California's population and economy will stop growing. Accommodating that growth will require major commitments to reducing water consumption and increasing supply.

Unlike previous droughts, the current shortage of water is largely the product of long-term climate change because of global warming. This means that the shortage will not abate without major changes in how we consume water. The cheapest and easiest way to increase water supplies is conservation. Even small increases in the efficiency of agriculture's use of water can produce huge savings. Cutting back landscape irrigation, which accounts for more than half of urban and suburban consumption, is another option, as is treating and recycling water. Finally, rain and snowmelt can be collected and stored for future use.

As things stand now, California is rapidly approaching the limits of growth. Those areas of the state with limited local water supplies already are off-limits for development, and those sectors of the economy that are big users of water, such as agriculture, are cutting back. We can extend the period of growth and prosperity by pursuing the measures mentioned above. What remains to be seen is whether that will just postpone the day of reckoning -- when we have done all we can do to cut consumption but demand still exceeds supply. At the point, California will have reached the limit of its growth.