Watering Holes, Grass Covered As one moves east along the BorderTransportationSystem route one will find more water sources to tap, and therefore there will be more water available for creating watering holes and grass areas. Valleys can be used for run off water collection from rain storms, the idea is to create lakes under a network of piers that are holding up towns, factories, and farms that are built on concrete platforms. This helps to prevent evaporation, and the used waste water can be filtered, purified, and sent back into the covered reservoir. Smaller ponds can be covered with a concrete roof that supports a grassy area for feed for animals and birds.  If near a community, the area can be used for growing plants. Index of ... Buried Reservoir Meets the Challenges of Residential Construction Reservoir Washington's water supply by covering reservoirs