Getting Mega Bucks with the Help of GIS

Apollo Teng, DIST

(This article appears in GIS News, Vol. 5 No. 3, April 1999)


Using some elements of the GIS databases and the geo-processing capabilities provided by GIS software, the DIST GIS Team has and are performing tasks that resulted in dramatic efficiency improvement over the traditional approaches undertaken by the County departments. The following highlights the projects that have impact to the revenues in the millions to the County or its citizens.


DIST GIS Team signed up the Local Update of Census Addresses 1998 program with Census Bureau. We reviewed 315,077 residential addresses provided by the Census Bureau and supplied back to the Bureau on January 6, 1999 39,423 NEW residential addresses (potentially representing 100,000 additional County residents). The Oracle property premise address table (maintained by DIST) and the multi-family addresses (maintained by M-NCPPC) are the two main input to the address matching steps. This represents a major step toward the goal of complete census count. In terms of federal revenue sharing and the various federal entitlement programs (which are typically based on total or sub-groups of population), these additional residents to be counted are quite significant. (One Census source put the average per capita revenue sharing to be $1,000.)

County Office of Planning Implementation organized the inter-agency LUCA working group and helped coordinating the LUCA activities between the County and municipalities. State Office of Planning presented to the working group their approach to LUCA program—identifying high growth areas and areas with large differences between Census addresses and local lists. DIST separated out addresses for the municipalities for their review effort. DIST also generated comparison plots showing TIGER/Line 97 and County’s up-to-date GBF/DIME for the cities.

DIST GIS Team has accepted the invitation from the Census Bureau to conduct LUCA 99 later this year. This would give the County another opportunity to update the Bureau’s (residential) mailing list for the County so that the goal of Complete Census Count can be achieved.

Agricultural Preservation

For the second year in a row, DIST GIS Team provided the GIS support for the Rural Legacy programs administered by the Agricultural Services Division of the Department of Economic Development. We not only submitted all the necessary hard-copy maps, but made the digital version available to State Department of Natural Resources, Office of Planning, and M-NCPPC for their review purposes.

The County obtained $3.7M from the State last year for the purpose of purchasing easement from prime farmland parcels targeted for preservation. Montgomery was among the top counties receiving such funding from the State. DED applied for funding to the tune of $2.5M this year.

DIST is nearing completion of developing a modeling application. This will allow the AP planners to perform quick (economic) analyses (a couple of minutes) on parcels that are candidates for AP. Previously the AP planners spent a couple of days (if not more) to do similar analyses for a land parcel.

Allocating MVA Rebates

For the third time DIST GIS Team is processing the annual MVA registration file for the Department of Finance. This is to allocate 629,964 registrations to County and the municipalities within the County for the State MVA to disburse the rebates. Using GIS technology (specifically address matching and point-in-polygon evaluation), we accomplished the task in about three person-weeks during the past two years. (Previously Finance had to spend well over six person-months to accomplish the task.)

For processing this year’s file, initial machine matching of the addresses yielded 96.6% match rate. The bulk of the analyst time will be spent on interactive correcting fallout addresses and matching the 19,000+ fallouts. The GBF/DIME and Municipalities coverages are the databases supporting this project.

The State rebate is based on the number of registered vehicles and the number of state route miles within the jurisdiction. On average, it is about $40 per registered vehicle. For 1998, 514,671 of the 616,275 registrations were outside the municipalities, but within the County. This translated to that County received about $20M from State as rebates.