(Martin W. Doyle is an associate professor in the Department of Geography at the University of North Carolina at Chapel Hill and a GSK Faculty Fellow at the Institute of Emerging Issues at NC State University.)

As spring rains wash away our short-term memory of the 2007 drought, the gubernatorial candidates should remain keenly aware of the water challenges that North Carolinians face in the coming decade: infrastructure, finances, and changing climate and land use.

First, water and sewer infrastructure is in desperate need of expansion and repair.

North Carolina's population will grow by almost 50 percent in the coming 20 years, while the number of people served by public water and sewer systems will grow more than 70 percent.

Both of these trends will create a substantial demand for more infrastructure. Yet our state's water and sewer infrastructure is not permanent, and a growing portion of the existing system is reaching the end of its expected lifetime.

Thus, there are competing and growing demands on water infrastructure funding: repairing and replacing existing pipes and equipment, or expanding to serve new customers. Combined, the North Carolina Rural Economic Development Center estimates the price tag of our water and sewer infrastructure needs to be in excess of $16.6 billion.

Second is the issue of where the money will come from.

In the past, funding for water and sewer infrastructure came from a mixture of federal, public and private financing -- loans and grants. Now, loans from private institutions are the largest source of capital for water and sewer infrastructure, with the state providing smaller and intermittent amounts of funding.

The new reliance on private financing has created a conundrum. Private lenders will only loan to municipalities considered credit-worthy, which is generally limited to medium and large municipalities with high credit ratings. Smaller municipalities must often rely on credit insurance to secure a loan with reasonable interest rates.

A potential side effect of the subprime mortgage crisis and associated credit crunch has been to make it harder for municipalities to secure funds for critical infrastructure. Municipalities with lower credit ratings may be forced to pay more to borrow money or, more likely, put off infrastructure projects.

Finally, changing climate and land use will only exacerbate our water problems.

Climate change means not just warming but increased precipitation and flooding as well. Ironically, it will also raise the likelihood of periodic drought as well.

Land use changes in North Carolina compound the problem. The dramatic spread of urbanized areas increases the intensity of floods and droughts.

Projections for future periods of precipitation and flooding are sobering. Even more so is the fact that our current infrastructure, built in the mid-20th century, was designed under environmental conditions that will no longer exist. It is now impossible for climate or land use change to be reversed in a reasonable time period, leaving adaptation as the only option to deal with this new climate.

Some water and sewer systems may need to be retrofitted or replaced; others may need additional infrastructure to provide some buffer capacity. At a minimum, our planned infrastructure expansion must be designed under this new reality of an altered environment. All of this adaptation will have to come at extraordinary and likely unplanned expense.

North Carolina residents showed a willingness to change their lifestyles in response to water shortages in 2007, and Gov. Mike Easley embarked on a public water conservation campaign, cutting water use across the state during a critical time. The next governor should harness this momentum to update the state's strategies and plans for the future.

Most importantly, the next governor must confront the need for large investments for our future water supply. Such actions will take decisiveness and long-term vision for the state, as well as continued commitment by residents in support of critical investments in our state's water infrastructure.