Orange County uses groundwater study for GIS

The Orange County Water Authority (OCWA) in southeastern New York State completed a landmark study of groundwater resources one year ago. The study is providing data for municipal planning and a well-head and aquifer protection program, and is also the basis of a county-wide GIS with applications from Emergency 911 service to economic development.

Orange County, which comprises 852 square miles and 42 municipalities is home to approximately 315,000 residents, two-thirds of whom are supplied with public water. Over the past decade, the county has experienced substantial growth in residential and commercial/industrial development, resulting in a significant increase in groundwater supply development and the need to identify long-term water resources.

In 1992, the OCWA launched its county-wide groundwater resources study. Completed in May 1995 by Leggette, Brashears & Graham, Trumbull, Conn., the study is the largest in scope to date in the state and one of the largest undertaken in the United States.

It includes existing groundwater information; an inventory of existing and proposed groundwater supplies; estimates of water demands to the year 2020; and an inventory of existing and potential groundwater contamination sites.

“We wanted to give a comprehensive information resource to the communities throughout Orange County that they can use to plan their water supply development and protection,” says Jay Beaumont, head of the OCWA.

The study determined groundwater is a feasible and favorable source for additional water supply development for the foreseeable future. It showed that the development of existing and new groundwater supplies across the county will be sufficient to meet the county’s water demands for at least 25 years into the future.

Data from the study are providing two important benefits, according to Beaumont. “First, we’ve pin-pointed on the maps the areas where we think there is a high probability of finding additional groundwater, and that information is proving valuable to all the communities as they start looking in the areas they want to develop,” I says.

For example, the town of Montgomery is using the study’s data to compare areas that are favorable for ground-water development with several sites the town wants to promote for commercial and industrial development. Orange County used the data to identify sites for two wells to supply water to a proposed jail site in Goshen.

Secondly, the OCWA is using the data to develop a well-head and aquifer protection program. Most of the communities in Orange County follow NYS Department of Health guidelines, which recommend a 200,foot sanitary radius around each well.

However, the state recommends monitoring and use of best management practices in a wider area. OCWA is studying 23 well fields to define the critical area for protection around each site.

Development guidelines will be set next. “Our goal is consistent well-head protection guidelines across the county,” Beaumont says. “We will use this data to educate community leaders as to the importance of protecting well heads, and how to do it.”

At the inception of the study, county officials decided the information would become the basis of a comprehensive GIS for a number of county agencies and departments. OCWA selected the Auto-CAD system, which will run on a personal computer platform.

“The county has determined that the best way to improve our economy is to make this information available to anyone who needs it,” Beaumont says. “We believe that in the long run, the secondary benefits of increased economic activity will more than compensate the county for the cost of developing this information.”

With this in mind, the OCWA staff met with colleagues in the planning, health, real property and tax map and emergency management departments to identify the mapping information they needed and incorporated these and additional mapping layers in the groundwater resources study.

Furthermore, the OCWA and the county are melding the groundwater study maps with maps of roads, streams, buildings and parcel boundaries that are being prepared for the county’s enhanced Emergency 911 system.

In another application, the GIS will enable a partnership that is marketing the county to prospective businesses to identify parcels of land that fit those businesses’ criteria. The maps will enable them to trace roads and determine distances from interstate highways.

Results of the groundwater study have allowed Orange County to better plan its water supply needs well into the future, and the study is quickly becoming a powerful tool in the county’s overall economic development strategy.