Gov. Jerry Brown recently declared a drought state of emergency. His proclamation gives state water officials more flexibility to manage the supply throughout California under drought conditions.

This announcement should not come as a surprise to Southern Californians, being that we live in a semi-desert region. The average rainfall in the region is 13 inches. However, rainfall in 2013 was a mere 3.6 inches, making it the driest year on record.

The declaration has caused a bit of panic and rightfully so. Cities, businesses and residents rely on water for economic growth and sustainability and to preserve public health.

Orange County's gross domestic product is $188.9 billion and its taxable sales are $51.7 billion, making it the 39th largest economy in the world.

So do we have enough water supplies to get us through this drought and support our vital economy? Will there be mandatory restrictions? Will our water rates go up?

I am pleased to say Orange County will weather these dry conditions better than other California regions, thanks to many of you who have supported investments in local water infrastructure projects and have made personal commitments to implement water-use efficiency measures in your homes and businesses.

Thank you for having the foresight to make these investments and change water-use habits. Despite increases in our local population, total water demands for our region have remained relatively stable, which shows we are becoming more efficient in our water use.

You are about to see some of the benefits of these past actions, but we are still not completely out of the woods.

So how good of a position are we in and how long can we hold on? North and central Orange County are in a unique position, having a local groundwater basin. Groundwater levels are falling quickly but are still within their normal, historic operating range.

In California, we are expected to experience droughts three out of every 10 years. Knowing this probability, the Orange County Water District saves reserve funds to prepare for and respond to drought conditions.

The district spent $44 million, from accumulated reserves, in fiscal 2011-12, purchasing 92,000 acre-feet — one acre-foot of water is enough to serve two families for a year — of imported water from the Metropolitan Water District of Southern California.

This helped to refill the groundwater basin despite less than average Santa Ana River flows. This strategy put Orange County in a better position than other regions.

When full, the groundwater basin, as a reservoir, holds about 500,000 acre-feet of water. We began the year with about 210,000 acre-feet in storage. If we have another dry year, we expect our storage levels to fall to about 140,000 acre-feet as of June.

Storage levels have been this low in the past. However, seawater intrusion from the Pacific Ocean can become a bigger threat with the lower water levels. Additionally, little water storage is available in case imported water supplies are significantly reduced. OCWD is currently spending its remaining water reserve funds — about $22 million — on additional MWD imported water this year while it is available to help counter the effect of reduced rainfall on the groundwater basin.

In addition to saving for a not-so-rainy day, continuous planning, designing, building and operating of cost-effective water infrastructure projects have been core functions of OCWD for more than 80 years. The community's investment in water infrastructure is fundamental to our region's ability to sustain itself in drought conditions.

With community support, OCWD recently invested $142 million to expand the Groundwater Replenishment System, an award-winning water purification system that takes treated wastewater from the Orange County Sanitation District and purifies it to meet or exceed drinking water standards.

The expansion, which will be completed in early 2015, will produce an additional 30 million gallons a day and 32,000 acre-feet per year, taking groundwater system production to 100 million gallons a day. In addition to being drought resistant, groundwater system water is about half the cost of imported supplies and is controlled locally, saving cities in our service area millions of dollars annually. The expansion will allow stable pumping from the groundwater basin.

Other investments made by local water agencies, such as the Irvine Ranch Water District and Mesa Water District, to construct wells and treatment plants that access isolated pockets of groundwater, have also reduced our region's need for imported water. And MWD's local agency, the Municipal Water District of Orange County, has implemented water conservation programs that have helped make the region more efficient with the supplies we receive.

While the Groundwater Replenishment System, successful groundwater management, local infrastructure and conservation have made the region significantly less vulnerable to drought compared with other cities in California, we need to continue to do more to protect and maximize water supplies not only in Orange County but throughout the state.

We need to maximize water reuse and tap into the 1.3 billion gallons of treated wastewater from our sewer systems that get lost to the Pacific Ocean every day in Southern California. We need to continue to practice water-use efficiency year-round, not just in times of drought. And we need to explore other possible solutions, such as ocean desalination and water transfers.

Orange County can breathe a little easier than other communities because of past efforts, but as weather patterns continue to become more extreme, we need to keep planning and investing in our water infrastructure if we want to continue to have a reliable water supply.

SHAWN DEWANE is president of the Orange County Water District Board of Directors.