They can reduce that risk by having very long tubes that can be re-positioned from the surface using ships to take water from different locations while the curr

They can reduce that risk by having very long tubes that can be re-positioned from the surface using ships to take water from different locations while the currents replenish the other locations. Or just have several tubes to draw from. Like rotating a pasture. No doubt they will need to actually monitor and plan for this or they will likely create a disaster.