Given what we've faced in the past decade in terms of drought, and adding the future uncertainty posed by climate change, it's safe to say that 50-year predictions include a large measure of hopefulness.

However, we are very fortunate to live in a state that has a long history of dealing with water issues in a robust and forward-thinking manner. The decades-long push for the Central Arizona Project, the Arizona Groundwater Management Act and our evolving commitment to water conservation have set a strong foundation to build upon to meet our future water challenges.

Arizona's water supplies will become more diverse as we begin to use currently underutilized resources. Probably chief among these are our wastewater supplies. The technology to fully recycle this water already exists and the costs are dropping. By 2062, potable reuse, probably through managed recharge and recovery, will be standard.

Other resources include poor-quality-groundwater supplies. Desalination of water is energy intensive, but it is likely that renewable-energy sources will mature in the decades to come, giving us the capability to economically treat and use brackish ground and, possibly, sea water.

We have used more than 7 million acre-feet (nearly 2.3 trillion gallons) of excess Colorado River water to augment or replace groundwater use since 1996. We will recover these stored resources when needed.

Conservation continues to gain momentum throughout Arizona. Through innovative technology, but more important through individual and community commitment, we will increasingly rely on rainfall and storm water to meet our outdoor water needs. Retrofit of older homes and commercial sites, and increasing water efficiency in new construction, will drive per-personal demand to new lows.

While climate change will present many challenges, water managers, politicians and scientists are now seriously and collaboratively discussing and researching what we can do to mitigate impacts to our water supplies.

Collectively, we have the capability to protect our environment, quality of life and economy, provided we continue down the path we've begun. I have high hopes that while we face major challenges, Arizonans will make the right choices.

David Modeer is the general manager of the Central Arizona Project. As the former director of Tucson Water for 10 years, he successfully guided the utility through one of the most difficult periods in its century-long history.