Well hydraulics is based upon observations of problems and solutions on many wells. Clearly variable production with depth due to different velocities down the length of the well can result in excess sand pumping, excessive entrance velocities, enhanced biofouling and mineral encrustation, and also "unsafe" bacterial samples. The bottom parts of many wells are essentially dead zones similar to dead ends in water distribution systems. The lack of up-hole velocity leads to water quality problems and limitations in rehabilitation. At the bottom of the well where there is a possibility of more stagnant zones, the water will appear murky, cloudy or even black and yet, at this site, the biofouling and mineral deposits may not extend as far back into the formation. The suction flow control devices would be used to reduce the entrance velocities impacting the surrounding formations that carry the fines that lead to the mechanical blockage problems.