Complex sentence: Despite the promise of jobs and improved infrastructure the population balked at the proposal that would see the town replaced with a kilometer wide pit which would generate enough pollution to destroy the region's agriculture and contaminate the limited water supply.
Split into simpler sentences: Despite the promise of jobs and improved infrastructure the population balked at the proposal. They did not want to see the town replaced with a kilometer wide pit and were concerned that the mining operation could generate enough pollution to destroy the region's agriculture and limited water supply.