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<br />Land'. End
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<br />(2~27 78
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<br />Basalt cap's shape on Grand Mesa shown in drawing
<br />,..USGS plans to drill to see if water trapped within
<br />
<br />USGS prepares fordrining
<br />proposed on Grand Mesa
<br />
<br />, By William H. Nelson
<br />Sentlnelstaft writer
<br />
<br />A U.S, Geological Survey team will
<br />,spend winter and spring preparing
<br />for the, proposed drilling through the
<br />basalt cap formation on Grand Mesa.
<br />,Drawing specifications, inviting
<br />bids, and other details are included in
<br />the work to be done,
<br />Drilling will start in summer after
<br />snow has melted,
<br />The objective of the program is to
<br />find if theories are correct that high
<br />quaUty ,water is trapped in fractures
<br />of the rock and in layers of rubble
<br />sandwiched between the layers of
<br />- basalt.
<br />There are beUeved to be eight lay-
<br />ers of basalt with seven layers of
<br />rubble, Geologists who have studied
<br />'Grand Mesa beUeve a river flowed
<br />from west to east-opposite of the way
<br />Kannah Creek now flows-When lava
<br />from deep in the earth came to the sur.
<br />face, it spread westward over, the
<br />river valley,
<br />
<br />The basalt from the lava weathered
<br />and broke into rubble. Then another
<br />flow of lava covered the area. This
<br />was repeated six times, There are be-
<br />lieved to be eight layers of basalt and
<br />seven of rubble.
<br />The water is beUeved to be trapped
<br />in the rubble and in the fractures in
<br />the basalt.
<br />Beneath the basalt and rubble is an
<br />impervious claystone. Impervious
<br />means water does not seep into it or
<br />through it.
<br />There will be at least four wells and
<br />Possibly as many as eight, depending
<br />
<br />upon how far money ,aliocated to the
<br />drilling goes, Some of the welis will
<br />be for test pumping of water and some
<br />will be observation wells to observe
<br />how niuch the water drops from the
<br />pumping" ,
<br />U,S. Geological Survey has appUed
<br />to the Four Corners Regional Commis-
<br />sion for $90,000, about half the cost of
<br />the project.
<br />This would be 200 billion gallons of
<br />water. As much as 640,000 acre-feet of
<br />water may be trapped in the rubble
<br />and fissures, It is probably renew-
<br />able. That is, water from rain and
<br />melting snow soaks intothe formation
<br />in spring and summer. In dry years,
<br />there would be less water, and the
<br />level in wells might drop, oniy to rise
<br />when there is' a heavy snowpack on
<br />the mountain.
<br />The basult and rubble layers are
<br />about 400 feet thick at the west end of
<br />the mountain and are, believed to be
<br />much thicker in the eastern end,
<br />Four ground water specialists are
<br />stationed at the USGS office in the As-
<br />, pinall Federal Building, Fourth and
<br />Rood. They are Ralph Patt and Tom
<br />Giles, hydro-geologists; Briane Adam,
<br />Umnologist; and Kim Goodard, geo-
<br />chemist. Limnology is the study of
<br />lakes, pondS and streams.
<br />The team is also doing work on un-
<br />derground water sources in San Mi-
<br />guel and North Fork of the Gunnison
<br />areas.
<br />Some of the water from the basalt
<br />formations may find its way into some
<br />of the lakes on the mesa, but some
<br />may be in what geologists and water,
<br />speciaUsts cali a closed basin. Water
<br />remains ill a closed basin exceptior
<br />
<br />some that evaporates through frac-
<br />tures unless it is pumped out.
<br />'Patt wouldn't conjecture on how the
<br />water would be used or by whom. He
<br />said the job oUhe USGS team is to lo-
<br />cate the water and let water users,
<br />other government agencies, and the
<br />courts decide on the use,
<br />But with energy development,
<br />USGS took the position the source
<br />should be explored for possible use in
<br />energy and other development.
<br />The matter of who could tap the wa-
<br />ter and who could use it could be the
<br />subject of court decisions and negotia-
<br />tions, The federal government claims
<br />what is called reserve rights, These
<br />are rights to water dating to the crea.
<br />tion of a national forest such as Grand
<br />Mesa. Oth\'l reserved rights involve
<br />water for National Parks and
<br />monuments.
<br />Under Colorado law, there is a dif-
<br />ference between water trapped in a
<br />closed basin and water that is tribu-
<br />tary to a surface stream.
<br />The USGS study may provide sO,me
<br />answers to the question of whether or
<br />not the basalt formation would be con-
<br />sidered a, closed basin.
<br />It is possible the basalt formations
<br />might be tapped by horizontal tunnels
<br />into the rubble, This would eUminate
<br />at least some pumping, '
<br />The Grand Mesa exploration could
<br />provide information useful in tapping
<br />other basalt formations near Glen-
<br />wood Springs, Steamboat Springs and
<br />Colorado Springs, Places using wa-
<br />ter from basalt formations include
<br />Hawaii, east Central Washington, In-
<br />dia, Saudi Arabia, the Canary Isalnds,
<br />and the Soviet Union.
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