For almost a year now, the Israeli public has been the target of a highly effective public relations campaign by the country's Water Authority. Stark images of desiccated humans cracking like hardened desert soil, along with the more comely admonitions for abbreviated showers from supermodel Bar Refaeli, reinforce existing perceptions that Israel's chronic water scarcity is getting worse.

It is. The campaign sets the stage for the promulgation of a series of important water conservation regulations, from bans on sprinkling lawns to cuts in agricultural water allocations. In the face of a critical crisis, it is good to know that one government agency is launching a comprehensive strategy intended both to expand water supply (through new desalination plants along with upgrading of wastewater treatment and recycling) and reduce demand.

Recently, though, skeptical voices have raised questions about the campaign's legitimacy and the actual severity of the present situation. Haaretz columnist Akiva Eldar wrote earlier this week ("Nonexistent water," May 19) how, "The national brainwashing over the Kinneret's wretched waters spits in the face of all humanity, while pretending that the spit is (lack of) rain." Eldar attacked present policies as excessively draconian, referring to a letter written to the minister of infrastructure by researchers at the Technion's Grand Water Research Institute. The latter claim that 100-150 million cubic meters of water could immediately be added to present supply by a series of simple measures, including better utilization of industrial wastewater, changes in the way road and earth works are undertaken, better utilization of recycled effluents and broader use of "grey water" from domestic sinks and showers.

Israel, for years a world leader in water-saving technology and policy, must remain open to any and all innovations. Indeed, when the Australians developed a toilet, in the late 1990s, that used less water per flush than those sold in Israel, water authorities were quick to impot the thriftier standard. New suggestions for water savings should be considered at a time when real sacrifices are being made for a reasonable national hydrological balance.

It is important, then, to remember that Israel's present crisis is largely a result of complacency among treasury officials, who systematically stalled and stymied numerous government decisions to dramatically expand the construction of desalination facilities. No serious water professional in the world doubts that a substantial increase in local water supply is imperative. The involvement of the Technion experts is certainly welcome, but their suggestions must not be used as an excuse to avoid critical, immediate investment in infrastructure. While additional conservation measures may make a small contribution to national efforts, they will not change the grim basic facts about Israel's water situation:

- Average annual rainfall in Israel has fallen by over 10 percent during the past 16 years. For a fifth consecutive year, this winter Israel experienced drought conditions, with only 85 percent of average rainfall reaching the north, and 75 percent falling in the center and the south. Climate change, it appears, is no longer a gloomy projection by Al Gore, but a new hydrological reality.

- Israel is operating near or below the "red lines" that demarcate maximum safe extraction from major water resources. There is a high likelihood that, despite considerable cuts in allocations, water will continue to be pumped below those levels, at the risk of salinization of the remaining fresh waters. The Kinneret is indeed at its lowest point in recorded history.

- While the permanent nature of the 1995 Oslo II interim water agreement has conveniently allowed Israel to ignore the drastic situation among its neighbors, the crises facing Jordan and the West Bank are critical. Average Palestinian per capita consumption levels are 50 liters per day - substantially lower than the World Health Organization's recommended minimum of 150. A final, equitable peace accord will have to provide them with supply commensurate with minimal international standards - which translates into conceding a sizable proportion of present Israeli water supply. Desalination is the only feasible option with the potential to expand the pie and ease the hydro-hysteria that characterizes so much of this discourse.

- Israel's streams remain the country's environmental orphans. Despite decades of efforts, not a single river has made meaningful progress toward restoration. The absence of minimal flow rates is one of the main reasons for the streams' abominable conditions and decimation of aquatic habitats. If we are ever going to do justice to Israel's ecological systems and surface water resources, we will need more water. Much more water.

A closer look at the figures in the Technion professors' letter reveals considerable imprecision in basic facts and figures. For instance, Israel's Water Authority points out that the amount of water wasted on construction and unutilized wastewater is in fact much lower than that presented. But nitpicking over percentages misses the point. Instead of rekindling the old debate over the need for desalination, the academic community should focus on responsible implementation.

The Ashkelon desalination plant has energy demands commensurate with a city of 45,000 residents, and relies on fossil fuel-based electricity, at a time when Israel has to find ways to restrict greenhouse-gas emissions. Hence, finding clean, renewable energy sources for the new desalination infrastructure is a paramount challenge. In addition, we need to create clearer water quality standards and monitoring for the waste products of the desalination process - and of course minimize encroachment on the available beachfront. Australia has begun to require that new desalination plants rely on renewable energy. So should we.

During the 1950s, Israel's investment of $175 million in the National Water Carrier devoured 80 percent of investment in water infrastructure and a significant fraction of available foreign currency. This astronomical sum (at the time) was an investment that provided a sound agricultural basis for a young nation's economy and a reasonable level of national food security. Today, Israel is asked to make a far smaller commitment to tomorrow's sustainable water supply and maintaining a healthy farming sector. Just as our generation enjoys the sacrifice of a founding generation that understood the importance of water for a dryland nation, it would be proper to provide our children's generation with a sound hydrological future. The alternative is a continuation of the boom-bust allocations, inevitable over-pumping and irreversible damage to water resources. The government has finally begun to implement a strategy for expanding water quantity. Our job is to ensure its sustainability.

Prof. Alon Tal is on the faculty of the Jacob Blaustein Institutes for Desert Research, Ben-Gurion University.