Sinkhole, also called sink, is a topographic depression formed when underlying limestone bedrock is dissolved by groundwater. It is considered the most-fundamental structure of karst topography. Sinkholes vary greatly in area and depth and may be very large.
A spring is the result of an aquifer being filled to the point that the water overflows onto the land surface. They range in size from intermittent seeps, which flow only after much rain, to huge pools flowing hundreds of millions of gallons daily.
A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Caves are large voids created by water dissolving the limestone.
A collapse sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. Sinkholes may form gradually or suddenly, and are found worldwide.
Dahlstrom location - Collapse Sinkhole
This sinkhole is overgrown with vegetation which hides it location. I believe this is a collapse sinkhole due to the large circular opening. Note the tree on right. It is leaning into the hole. This sinkhole is in close proximity to the other sinks at this location.
Sinkhole at Dahlstrom Location
Classic hill country sinkhole. Note the wire net cover to prevent people or livestock from falling in. The opening may qualify as a cave if one could enter it. Note the linear shape of opening. It is inline with the Balcones Fault segment nearby.
Sinkhole near Jacob's Well
Sinkhole near Jacob's Well
Sanunders Swallett (aka Sinkhole)
Sanunders Swallett is a well known sinkhole in the Blanco Riverbed. It is located in western Hays Co. Water from the Blanco River enters this sinkhole causing a noticeable reduction in the Blanco flow. This stretch of the Blanco is referred to a sinking stream or river since it looses water as it flows downstream. Water entering Saunders Swallett recharges the underlying Cow Creek aquifer.
Photo Reference: Karst Systems of Hays Co. & the Edwards & Trinity Aquifers. Presentation to Kinder Morgan, Inc. 2/10/19. Barton Springs/Edwards Aquifer District, Hays Trinity Groundwater District.
Is This a Sinkhole, Spring or Cave?
The familiar Jacobs Well is designated as a spring. But it also neatly fits the definition of a cave which is below the water table. Jacob’s Well spring contributes water flow to Cypress Creek.
Beginning of the Walking Trail with Fields of Native Wildflowers
Stone Wall Designed to Control Floodwaters
Uncapped Source of the Comal River
The wells on this property, the real source of the Comal, were capped in the 1930's to provide more control of water flow in the area the Klingemanns regarded as a messy swamp.
The cap was removed from one of the springs in 2016 and visitors can see the water coming out of the uncapped well area of the stream and flow toward Landa Park.
Path Along the Stream that becomes the Comal River
A good walking trail follows the creek from the one uncapped well along a wooded creek bank until the stream and Blieders Creek join to flow on past the Heidelberg cottages toward Landa Park.
Then the walking trail follows Blieders Creek for a short distance and arrives back at the area that will be the event center.