The Trail Tank
The Trail Tank, located on our upper Ridge Road above the Hunters Camp, has been a functioning water resource for a long time. By the early 1990s, however, we saw clearly that its front side was gradually eroding, and its basin had filled to a considerable extent with silt. This meant that it overflowed regularly, not a problem since its spillway, on the West side of the tank, is bedrock.
Looking upstream, the eroding face of the dam could be seen in 1994, amidst mesquite trees reflecting the age of the tank:
From upstream, the silt-filled shallowness of the tank is evident. It often had a substantial growth of tumbleweed.
Still, it regularly received water, and cows were able to graze in these uplands occasionally when it filled (below, looking upstream):
In July of 1998, Ferron Bingham reconstructed the tank with his bulldozer, and it immediately filled with water (note the spillway beyond the men, mostly beyond view -- this is a bedrock spillway, making this a very stable tank):
Since it was largely composed of new earthen fill, the new tank lost its water at a fairly rapid rate -- the original waterline can be seen above the later one as of late August 1998 (below):
This led some of us to experiment with digging Bentonite into the basin of the tank during the winter of 1999: Below, the central part of the tank has been finished, and bags of Bentonite lie around the edges before being broken open, then spread with a rake:
Below, the Bentonite is being spread along the face of the dam, prior to being dug in with the rototiller (and then tamped down by pickup truck wheels run over the surface repeatedly):
and since that time the tank's water retention has definitely improved, enabling the cattle to graze and other creatures to rest in the Northeast sector of our grazing lease when the rains allow:
But even with the Bentonite slowing water infiltration, in the absence of rain this tank gradually dries by evaporation, as shown by this photo from January of 2001: