Drainage The BorderTransportationSystem will be built in both very dry and very wet areas of the nation and thus attention must be paid to proper drainage of the traffic and rail lines.  The rail line are suspended above the highway and slower speed areas, and thus rain falling on the open track system will be concentrated as it falls upon the lower level areas.  The proposal is to capture this water and direct it to covered ponds or reservoirs where it can be later used for irrigation, purification, or factory uses.  This water collection will be by gravity flow, no pumping is needed, and with proper design of the railroad tower system will not add to the cost of the towers, the cost being only the collection tanks and the routing to the collection tanks and from the tanks to the users.  This cost can be recovered by fees on the water use, and by having private industry and farms pay for the various components of the storage and distribution systems. Index of ... BTL Reservoir Liners Dams and Reservoirs - MIT Rain and Precipitation - USGS Thinking about an irrigation reservoir - *.PDF VapourGuard Water Storage Tanks, up to 5,050 gallon