"Software shows possible effects of land development,  By Carol Kinsley

'…In Sussex County, where there are now 73,629 existing "dwelling units" — the figure has been adjusted to account for vacancy rates — the total capacity under current zoning laws is 1,034,852 units. The number is not time sensitive, Donley explained. That's the total capacity of the 950 square miles of the county…'

Community planners for coastal areas of the Delmarva Peninsula are using a new tool to answer the question "What if?" when it comes to growth issues.

At a recent workshop in Georgetown, members of a coalition called DAWN, the Delmarva Atlantic Watershed Network, said they were committed to the use of Community Viz, software that incorporates GIS (geographic information systems), computer mapping and community-specific data to provide a 3-D glimpse of the effects of plans for the future.

"It is a way to visually represent land use," said Dr. Bill Mc-Gown of University of Delaware Cooperative Extension. "It allows us to 'try things on' and see the consequences." Development of the software was underwritten by the Vermont Country Store to help communities plan better.

Planning is important on the Delmarva Peninsula, a comparatively undeveloped area surrounded by millions of people who live within a six-hour drive, explained McGowan. "This is a special piece of the world," he continued. "We need to think about who we are and what we want to be as a region." The region addressed by the workshop includes Sussex County; Worcester County, Md.; and Accomack and Northampton counties in Virginia. DAWN includes the Maryland Coastal Bays program; the National Oceanic and Atmospheric Administration (NOAA); Maryland, Virginia and Delaware Coastal Zone Management; and University of Delaware's Coast Communities Enhancement Initiative  (CCEI).

Dave Wilson of the Maryland Coast Bays program started DAWN with Ed Lewandowski, executive director of the Center for the Inland Bays. Recognizing the Peninsula as a region with its own biological characteristics, Wilson said it is important to try to keep the ecosystem intact.

The effort was begun two years ago with a brain-storming conference on planning for Delmarva coastal communities. Elected officials, planners and business leaders joined six months later, and early this year the Coastal Bays program got a $60,000 grant to further the regional effort.

At meetings like the one in Georgetown, held in each of the four counties, planners got a look at what "build out" will look like if every potentially developable lot has the maximum number of structures built on it. Presenting the visual "reality check" was Chuck Donley of Donley & Associates in Colorado Springs.

Depending on the data entered, the Viz software creates layers that show zoning or future land use, unbuildable areas, existing development and sewer service areas. Data can include prime agricultural land, rare or threatened and endangered species, aquaculture operations, submerged aquatic vegetation (SAV), wetlands, protected lands and even sea level rise. One key element that can be produced is the amount of nitrogen and phosphorus that would be generated by those dwelling in all of those houses. Limiting nitrogen and phosphorous loads are important to protecting water quality, and treatment of all that wastewater must be provided for.

Donley said figuring the ultimate capacity is simple math. The Viz software, however, computes all the other factors such as tidal and nontidal wetlands, flood plains, public lands and conservation areas to give a more accurate visual picture.

In Sussex County, where there are now 73,629 existing "dwelling units" — the figure has been adjusted to account for vacancy rates — the total capacity under current zoning laws is 1,034,852 units. The number is not time sensitive, Donley explained. That's the total capacity of the 950 square miles of the county.

The three other counties, with a combined area of 1,150 square miles, would reach total build-out at about 135,000 dwelling units. Donley noted that some landowners may choose to build fewer units than allowed. If the community does not like the future picture it sees, changes can be made to the parameters. Planners could choose to protect green infrastructure — large forested blocks, or prime agricultural lands. "The state knows it can't save all the green on the map," Donley said. One member of the audience commented, "If all that buildout happens, we'll never achieve TMDL (total maximum daily loading — a measure of nutrients going into the water)." "We have to preserve the areas that are protected now." The images from Viz will be introduced to a larger Sussex County audience, including the public, in the spring, McGowan said."