"The worst crisis of all time, in my view, is the critical global shortage of fresh water," says " Larry Edelson. In Money & Markets, the resource expert offers four water sector plays.

"The world's water crisis is now getting worse by the day. And the global financial and credit crisis is merely one reason why. Another is the ongoing modernization of major parts of the world, which is increasing demand for water, while at the same time polluting it.

"Yet another is major droughts around the world, including in our own back yard, where 60% of the U.S. is officially experiencing a drought.

"New technologies and techniques for better water supply management and improved conservation on the demand side could potentially avert a worldwide disaster. And as a long-term investment, water is one of my favorites. For both its tremendous social cause as well as its profit potential.

"Warren Buffett's Berkshire Hathaway revealed a new position in Nalco Holding (NYSE: NLC); it's my favorite pure play on water filtration," says Chris Mayer in Daily Wealth.

"With a $1.6 billion market cap, Nalco is a small-cap stock, but it's actually one of the world's largest water-treatment companies. Customers use Nalco's products and services to prevent corrosion, contamination, and the buildup of harmful deposits.

"Buffett picked up 8.7 million shares. That makes Berkshire the second-largest shareholder in the company, with a little more than 6% of the shares.It's easy to see what Buffett likes.

"It's no secret that the world is facing a severe water shortage; many experts, believe the next major war will be fought over water, not oil," says Marc Lichtenfeld.

The senior equity analyst for the top-notch growth stock advisory, Xcelerated Profits Report explains, "Desalination is likely the only way the world's water needs will be met. And one company that will benefit is Energy Recovery (NASDAQ: ERII).

"Just how severe is the shortage? Demand for fresh water will exceed supply by 50% in 2025, with one-third of the Earth's population living in countries with water scarcity. The bottom line is that if we plan to feed and provide water for everyone, we're going to have to find a way to use more water more efficiently.

"In a few years we'll be staring at new highs in the prices of many natural resources," says Larry Edelson, a specialist in resource-related stocks. In Real Wealth, he looks at two exchange-traded funds focused on food and water.

"Mind you, the U.S. and global economies will not get back to the growth levels we've recently seen, not anytime soon.

"But they don't have to for natural resource prices to soar again. The chief reason they will climb again: Massive, worldwide currency devaluations, especially in the U.S. dollar.

"Moreover, natural resources will get a huge boost from the massive infrastructure spending that is now commencing around the world. I expect two key sectors in particular to get a big boost, almost immediately - agriculture and water.

This post is part of a special report, A Dozen Ways to Play an Obama Building Boom.

"Stocks in the water sector could soon flood their shareholders with a deluge of profits," says value investor Nathan Slaughter. In his Half -Priced Stocks, he explains, "Even in the 21st century, UNICEF reports that a staggering 1.1 billion in emerging markets still lack access to safe drinking water.

"And here in the U.S., the EPA has said we need to spend $275 billion to replace aging facilities -- including 800,000 miles of leaky, corroded pipeline that haven't been upgraded since the 1800's in some places.

"We see an incredible opportunities for the companies trying to combat the problem, particularly those involved with water distribution pipes, treatment facilities, purification technologies and other critical infrastructure.

"My top play in the sector is Veolia Environnement (NYSE: VE), a global juggernaut with $45 billion in annual revenues, operating on every continent.

"From humble origins supplying water to Parisians over 150 years ago, Veolia has grown to become the world's largest water utility. Today, it provides water and sewerage services to 130 million people in nearly 60 countries worldwide.

"During times such as these, I like to focus on big companies with clean balance sheets that pay decent dividends," says Glenn Rogers.

Here, the contributing editor to Internet Wealth Builder reviews his current stock holdings for a trio of global favorites offering upside potential while still allowing investors to "sleep well at night."

"Diageo Plc (NYSE: DEO) is well down from my original recommended price but compared to the overall market they have performed respectably.

"Meanwhile, the company recently issued a statement confirming its previous guidance of profit growth of between 7% and 9% in 2008.

"The company reported that organic net sales grew 6% in the three months to Sept. 30 and that there has been no material change in the financial position of the group during the period. Buy, with a target of $90.

"I have owned Knightsbridge Tankers (NASDAQ: VLCCF) longer than any other in my portfolio and it has never failed to pay a hefty dividend. The stock is currently trading at $17.40, thus yielding an incredible 17.2% based on a quarterly dividend of 75c a share.

"We see flowing profits from companies in the water sector involved with pipes, pumps, regulators and other equipment," notes Neil George.

In his industry-leading Personal Finance newsletter, the advisor offers a fascinating overview of three companies that help "utilities and other industries provide quality water service."

"Aging pipes are one of the most pressing challenges in the US and beyond. Studies show that in some municipalities, loss from leaky pipes accounts for as much as 10% of water consumption.

"Ameron International (NYSE: AMN) is a pipe manufacturer with operations on every continent. Earnings per share don't show smooth-line growth on a quarterly basis given the cyclical nature of construction. But it does show solid, year-over-year growth.

"There's some price volatility as investors are jarred with increasingly pessimistic domestic construction outlooks, but overseas earnings will continue to bolster the balance sheet.

"Watts Water Technologies (NYSE: WTS) manufactures pumps, valves and controls for a broad array of both consumer and industrial applications.

"Wealth building is about buying quality on the cheap; and you're not going to find the best water industry stocks at better prices than they sell for now," says utility sector specialist Roger Conrad.

In his The Utility Forecaster, the advisor reviews the three water stocks that earn a place among the core holdings in his growth portfolio: Aqua America (NYSE: WTR), Consolidated Water (NASDAQ: CWCO) and Southwest Water (NASDAQ: SWWC).

"All three of these water stocks posted disappointing first quarter earnings for very different reasons. However, all remain tapped into long-run, wealth-building opportunities.

"Aqua's first quarter results were by no means a disaster. But they lagged both last year's total and Wall Street estimates.

"Management blamed the slowing economy's impact on housing starts in what had been fast-growing systems, rising bad debt, lower commercial sales, delays in fully digesting acquisitions in the South and longer-than-expected timetables needed to win rate increases.

"One essential commodity that is often overlooked by investors is water," says Gregory Dorsey, contributing editor to Stephen Leeb's Income Performance Letter.

He explains, "It's absolutely vital and is in growing demand for many reasons. And we've found an excellent way for income investors to ride this trend -- Paris-based Veolia Environnement (NYSE: VE). Here is his review.

"Veolia is not your typical utility, but it's still a utility that every income investor should consider. Veolia is the world leader in the management of water and wastewater services for local governments, industrial and service sector clients.

"It's also a world leader in the design, construction and operation of facilities for water and wastewater systems. With a focus on managing the complete water cycle from extraction to treatment to waste, Veolia stands ahead of its competitors.

"But although water is the chief attraction for us, Veolia generates steady revenue and income from other businesses as well.

"Its Veolia Environmental Services covers the entire solid waste cycle, including urban cleaning services, soil and site remediation, collection, sorting, transfer, treatment and recycling/recovery and is the world's largest waste management company.

"Water is the sleeper investment of the decade," says Jim Powell. "Although the world is focused on energy, clean water is in far shorter supply in many regions. That's even true in many parts of the U.S."

The editor of Growth Stock Alert suggests, "A great deal of money will be made by today's earlybird investors who buy strategic water stocks." Here are his favorites in the sector.

"Unlike oil, there is no substitute for water. Some investors mistakenly think that water is a low value commodity that's not likely to deliver good profits. What the critics fail to consider is the equipment needed to
obtain, purify, transport and recycle water is very expensive.

"Calgon Carbon (NYSE: CCC) is my first choice in a water stock. The company is the world's largest supplier of
granulated activated carbon, the principal purification agent for water. The company also supplies complete treatment systems for municipalities and private organizations.

"The company has 16 operating centers and 23 sales and service offices around the world. A few years ago

, the company expanded its purification business to include industrial liquids and gasses. Rising concerns about greenhouse emissions and other pollutants are giving Calgon Carbon another boost.

"I also recommend ITT Corporation (NYSE: ITT), the world's leading supplier of systems that move and purify
water. The company's treatment equipment is sold throughout the world under the Sanitaire, Aquious and WEDECO brands.