Water Well Conditions: What You Need To Know: And Why: Inside Diameter of Well Casing Determines the type and size pump that can be installed A factor in determining well storage capacity Well Depth Determines how deep you can place the pump or jet assembly Helps determine Vertical Lift A factor in determining well storage Static Water Level (How high does the water rise in the well when system is not in use?) A factor in determining well storage capacity Well Yield Helps determine total well capacity (Available from the Well Driller's log, or by test pumping the well.) Helps determine Discharge Capacity under Peak Demand Conditions Storage Capacity Helps determine whether water supply is adequate to satisfy Peak Demand conditions