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Navigating Controversy
GIS is a crucial decision-making tool in planning the future of a former marine station
By Christine Henry Officials in Orange County, California, are in the midst of planning the reuse of the 4,700-acre Marine Corps Air Station, El Toro. A victim of the end of the Cold War, the base is being closed down by the federal government.
The Orange County Board of Supervisors, charged with the responsibility of planning the base's reuse, is in the final planning stages for the El Toro Master Development Program.
With the Marine Corps' base came existing aviation facilities. Plans call for turning the aviation side of the base into a new regional airport with international access. In addition to the proposed commercial airport, a variety of non-aviation land uses are envisioned including cultural and institutional uses, a small business park, two golf courses, and a 970-acre habitat preserve.
The county is relying on a cutting-edge GIS prepared by Psomas (Costa Mesa, California) as a major decision-making tool in its planning process. Psomas was selected because of the firm's extensive GIS experience including the mapping of noise contours at Los Angeles International Airport, a multi-agency GIS for a consortium of San Francisco Bay-area cities, an extensive GIS for the City of Los Angeles' Stormwater Division, and GIS applications for the Republic of Turkey and Sri Lanka. El Toro
A new commercial airport at El Toro would add substantial air travel capacity to the region. Air passenger traffic in Southern California is predicted to double by the year 2020 to 178.6 million annual passengers, overloading existing airports. It is estimated that the new airport at El Toro, with its existing two 8,000' runways and two 10,000' runways, could serve from 10-38 million passengers annually. Orange County's only commercial airport, John Wayne Airport, has a single 5,700' runway.
As can be expected, there is considerable controversy surrounding base redevelopment. Whereas proponents see the proposed airport as crucial to support the region's air travel needs and take the burden off Los Angeles International Airport to the north, opponents are concerned about jet noise, traffic, air pollution, and the influx of airport-related development.
The planning effort looked at several airport scenarios, each represented graphically thorough the GIS, which has become critical in supplying hard scientific evidence for the various scenarios, according to Daniel McCroskey, Psomas project manager for the El Toro GIS.
All scenarios called for keeping the existing runway configuration. Therefore, GIS became the key to keeping new commercial aviation uses lined up with the existing runways. All new data regarding property boundaries and all land uses imported into the GIS had to fit correctly into the existing runway configuration. This was essential in order to stay within the "policy implementation line" surrounding the base, which prohibits any residential land uses inside the boundary. The line follows the 65 CNEL (community noise equivalent level) for military uses, which has been in place for years.
The GIS includes sound contour data for military aviation uses compared to sound contours for the proposed commercial aviation uses. Using support data from noise consultants, Psomas translated noise information into engineering-compatible data and ensured the data was accurately aligned with the existing runways. McCroskey notes that the true bearing of a runway must be correct to less than a degree. "Any deviation from the true bearing could make a difference in which community is shown as impacted by the proposed flight paths," McCroskey says.
GIS provides a concrete, scientific basis for analyzing the net change in potential noise impacts, in turn lending a high level of scientific backing to counter the misinformation that surrounds a controversial project.
GIS exhibits also were used in the hundreds of public meetings held by county officials. The public exhibits were "well received," according to Craig Ramella of the Planning Center (Costa Mesa, California), the firm charged with planning the non-aviation uses in the base redevelopment. "GIS lends an air of credibility to anything you present." Although the exhibits conveyed complicated information about the impacts of various noise contours, they also were much easier for the public to understand, given their graphic nature.
With the help of GIS to evaluate the impacts of each scenario, the planners looked at concepts ranging from 12 MAP (million annual passengers) to 34 MAP. The final plan calls for the airport at El Toro to support 28.8 MAP by the year 2020. Juggling Land Uses
Urban planning issues abound in a project this complex. The GIS Psomas is building in support of the El Toro Master Development Program is critical in the "juggling game" required to come up with a final land use concept that balances aviation requirements against all the other land use requirements in the proposed development program.
Acreage and land uses added into the GIS enabled planners to calculate acreage and make comparisons in order to arrive at the appropriate amount of space for each use: from cargo and maintenance facilities, air terminals and an 85-acre business park, to a 970-acre habitat preserve, and an 880-acre open space component that includes a wildlife corridor, two golf courses, and a large regional park complete with equestrian facilities and ballfields.
McCroskey points out that "like a big jigsaw puzzle," any time planners moved or modified a land use, the GIS was recalculated to ensure all requirements for each type of land use were met. For example, the location of a lighted golf course for night play might conflict with the adjacent airport use. The proximity of a golf course water hazard to the habitat area might attract geese and ducks that would present a hazard to aircraft.
"In fact, a great deal of the GIS effort went into managing open space and habitat corridors," notes McCroskey. The GIS incorporates data on habitat-sensitive species areas and wildlife corridors that impact placement of other land uses. For instance, planners are using GIS data to design the golf course and park around the habitat crossing corridors. Data Repository
Originally designed as a planning tool, the GIS Psomas is building has grown into the overall data repository for the development program. The database also contains Marine base utility infrastructure and existing buildings, topography of the site, hazardous materials site classifications (updated with remediation efforts), an 18,000-acre subset of county parcel data covering 133,000 parcels surrounding the base, county-wide demographic information, traffic analysis zones, and more.
Based on ESRI's ArcInfo and ArcView architecture, the work effort includes: base mapping system, requirements analysis, GIS system, GIS data model creation; GIS application, analysis and Web enabling; and an implementation plan. Challenges and Rewards
According to McCroskey, it has been a challenge working with the large number of consultants on the base reuse plan-from marketing analysts, engineers and planners to golf course designers and landscape architects. "Each consultant requires a different level of data accuracy, but we must maintain the data level for the highest common denominator," says McCroskey. All data is calculated through the highest degree of surveying and engineering design methods. "The guy with the toughest requirements is our benchmark; so everyone else benefits."
One reward that McCroskey points to is being able to use cutting-edge software that did not even exist a short time ago. ESRI's ArcView 3D Analyst extension to ArcView 3.1 allows 3D modeling to exist inside a GIS mapping environment. "This software is really exciting. We can model the terrain by overlaying aerial photography over wire-frame digital elevation models to show topography in 3D." The 3D software allows visualization and analysis of natural features and how they impact the base. Exhibits relating viewshed analysis, ground profiles, and flight path elevation diagrams were produced to convey a typically complicated subject matter. The virtual reality environment is also being used to visualize existing buildings for parties interested in leasing base facilities (there is a lot of Hollywood interest in leasing hangars). As new buildings are designed, and existing buildings demolished, the model can be dynamically updated to reflect these changes. Marines Set to Leave
The Marines are set to leave the base in July, and this phase of the El Toro Master Development Program is targeted for completion by the end of 1999. Next will come facility design, the development of an infrastructure plan, and a transition plan for the Marine facilities.
GIS is providing a strong analytical and scientific foundation for the planning process underlying the Master Development Program and for the Environmental Impact Report that will be released later this year. It will eventually support the development process itself, once the necessary approvals have been obtained. Complete build-out of the airport and non-aviation land uses proposed for the former El Toro Marine Corps Air Station is anticipated by the year 2020. About the Author:
Christine Henry is a writer specializing in engineering, GIS, and planning issues. Her firm, Henry Woodward Communications is located in Manhattan Beach, California.
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