BOARD01250

• Board Meeting Date: 12/9/1964
• Description: Minutes
• Board Meetings - Doc Type: Meeting

We are only concerned with the unconsolidated
deposits that fall between these daah lines.
All this area, of course, is colored. Finally,
the transmissibility of the sand and gravel
aquifer. The colors depict the range of trans-
missibility values.

The transmissibility map is based on
pumping tests and well logs, which define the
saturated thickness and permeability of the
sand and gravel aquifer. Transmissibility
ranges from 50,000 to more than 200,000 gallons
per day per foot. The variation is caused by
differences in saturated thickness or in per-
meability (i.e., type of material and sorting).
This map can also be used to determine well
spacing and to estimate the potential yield
of irrigation wells. Areas are outlined where
large-capacity wells could be developed to
exchange ground water for surface water. For
example, in areas where a transmissibility of
200,000 prevails, a well could be pumped at a
sustained rate of 1,200 gallons per minute and,
conversely, in tra~smissibility areas of 50,000
to 100,000 the well yield would only be 450
gallons per minute.

The hydrology of the system will b~ cuper-
imposed on the framework of the model as
previously described. We will program the
information obtained from the water level
measured in a thousand wells. These wells
were measured in October 1963, May 1964, August
1964, and October 1964. For eac~ of these
periods, water-level-change maps have been
constructed. An example of the water-level
changes is between October 1, 1963 and May
1, 1964. Other change maps depict the changes
in water-level from May 1, 1964 to August 1,
1964.

The differences in water-level measurements
on these maps are shown by colors. Declines
in water level are shown in yellow, green, and
purple. The colors are interpreted as follows:
yellow, 0 to -2 feet: green, -2 to -4 feet:
and purple, -4 to -6 feet. A rise water level

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