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~i603 12 Que s t ion: Will the Closed Basin Project turn San Lllis Valley into a dust Bowl? An~H....er: No, the operation of the Closed Basin Project will not turn the Valley into a dust bo~l. Th~ fears which many people have expressed on this suhject are based on mi~understanding. This misunderstanding focuses on two official ~tate- mente; about tilt" project. These official statements are: (1) "the Project will salvage water now being lost to evapotranspiration. and (2) "decreased plant vigor may result (from the operation of the project) in some areas. II SomE' people have interpreted these statements to mean that operation of the pro.jeet will result in the loss of existing vegetation from a V85t part of the. valley. That ie; not what the statements say, and it is not reasonable to believe this wi 11 happen. " " in the Closed Basin sump area, the water table is generally 2 to 6 feet below the surface. A. large amount ot 'Water evaporates from the project area every year. Pro.jeet facilities are de~igned to salvage some (not all) of this evaporated water by lowering the water tahle in the Closed Baisn sump area (only within the pr0ject boundary). A lower water table will reduce the amount of water transferred from the soil surface and from sOI:!e of the vegetation to the atmosphere. Water is transferred to the atmosphere fro~ leaves of growing plants (transpiration) and from the soil surface <evaporation) by a process called evapotranspiration. Plants in the San Luis Valley and the area of the Closed Basin (not including wetlands) are well adapted to low rainfall and moistur~ levels; however, they can and do use large amounts of water when it is available. The efficiency with vhich a plant uses soil moisture often decreases with too much available water. A point can often be reach~d wh~re high moisture levels reduce plant growth and survival. Where there a~e always very tligh water tables, the rate of plant growth will likely be less than if the water table and available water were 1001er. l.m/ering hi8h water tahles within pro- ject boundaries will not automatically result in the death oE all existing vegetation. Some plants will be adversely affected by lowering water tableS. Others will be helped and increased plant ~rowth will occur. r:vaporation of soil moisture can be very high when water levels are near or at the soil surface. The evaporation rate from a "et soil surface generally exceeds that transpired by plants under the same climate conditions. Redllcing water levels will decrease total water lost fro~ the soil surface and will often maintain gr?ater plant growth rates.