Abstract: Examples provide catchment modeling for identifying destination locations eligible for last mile delivery from source locations, such as a store or fulfillment center. The catchment modeling system divides a catchment area associated with the source location into a plurality of geohash blocks within a polygon fence. The size of the geohash blocks varies relative to proximity of each geohash block to a fence point within a polygon fence. The plurality of blocks includes a set of inclusion blocks within the predetermined distance from the source location and/or a set of exclusion blocks exceeding the predetermined distance from the source location. Data compression via polygon merging is performed. The compressed data is cached for utilization during catchment delivery eligibility determinations. If a destination address is within the set of inclusion address or absent from the set of exclusion addresses, the destination is eligible for delivery from the source to the destination.