How to Read the Well Data: The first selection below is a map showing the locations of
all the District’s water level monitoring wells. If you want to look at a
monitor well in the area you live, consult the map to find the closest well,
then select the corresponding well from the list below.
It is best to view the well data using an Excel
Spreadsheet. Once you open the spreadsheet you will see tabs below and
columns and rows of numbers. The first tab at the bottom is labeled
“Monthly Data”. Most District wells are monitored each month (though
there are exceptions). The first column in this tab shows the date that
the measurement was taken. The second column shows the depth in feet to
the water level. Since it is measured below the surface, the numbers are
shown as negative. The last column is the water level relative to sea
level. For example, if you are taking a measurement for a
well that is 200 ft above sea level and you measure the water level at -50 at
the site, then the measurement of the water level relative to sea level is 150
ft. We call this the elevation of the water level and it is a way to
normalize all the measurements of water level from the effects of local hills
and valleys.
The “Monthly Data” tab will have two graphs. The upper
graph shows the change in water level through time as a measurement of feet
below surface. This graph is always in blue. The second graph will
look identical, but it is showing the changes in water level relative to sea
level. This graph will always be in red. You may notice that some
well’s water levels swing wildly from month to month, whereas others stay
relatively constant. This is usually the effect of seasonal irrigation and
the relative location of that monitor well to large irrigation wells.
You will notice that some wells have lots of measurements
and some only have a few. The District started with only a handful of
monitor wells, but has been adding several each year.
A second tab at the bottom is called “Pertinent Info”.
In this tab is the reference name of the well, the corresponding state well
number (if one has been assigned), the physical address and the location from
latitude and longitude, the well depth and the elevation of the well.
Where there is information provided, this page will also show the screened
intervals (i.e. the sections of the well open to the borehole of the well).
A third tab is present on many wells and is entitled “Annual
Data”. The same columns that are present on the first tab are present
here. However, only annual measurements are shown. The annual date
referenced is the day closest to the start of irrigation season each
year. This will usually be the March or April measurement if
present. This chart takes out the seasonal effects and shows longer term
year-to-year changes in the aquifer’s water level. The corresponding
chart shows the change through time of the water level relative to sea level
(red line). If a well you are looking at does not have this tab, it is
because the well has not been measured long enough to have sufficient data to
show annual changes.
The District will update these charts every couple of months
as new data comes in. Check back periodically to see how the aquifer
water levels are changing.
