Various parking options are available around town. A screened fence surrounds the spring, but cutouts have been provided to allow viewing of the spring and small informational signs have been posted at various locations on the fence.
The city of Paso Robles pretty much owes its existence to hot springs. Throughout history and prehistory, people have come to the area to make use of the various hot springs around town. For a while in 1860s the area was one of California’s premier health resorts. Currently there are still a couple of hotels that are located at hot springs and another property allows inexpensive public access to their hot springs.
Apparently, a geothermal source some 400 feet below the surface is the source that heats the ground water. The exact nature of that heat source has not been fully described in the references I have.
The faults in the area are thought to play a significant part in the movement of the ground water in the area, creating the area’s hot springs. The springs and wells found in downtown Paso Robles may be controlled by an inferred fault that runs through the south end of town from the Rinconada Fault. This fault likely allows artesian (water under pressure) to flow up to the surface as springs.
The hot springs in the area also have a significant amount of hydrogen sulfide, the rotten egg smell noted around the spring. This compound is considered a contaminant should it reach the sewage treatment plant or the Salinas River. This is one of the challenges still facing the city in developing a final solution for the restoring the parking lot.
In addition to hydrogen sulfide, the hot springs are generally more saline that nearby cold springs and wells. While a cause of the added salinity is not proposed in the references, it could be from the ability for hot water to dissolve more salts than colder water.
Prior to December 2003, this spring did not exist. The epicenter of that earthquake was miles away on the coast, but shook up the area enough to alter the ground water flow along the subsurface faults forming this spring.
Unfortunatley, the paper signs that were attached to the fence appear to have been removed so you can't find the answers to questions 3 and 4. Logging requirements:
Send me a note with :
- The text "GC1FDYE Paso Robles Sulfur Hot Springs at City Hall" on the first line
- The number of people in your group.
- Find out what caused the large hole in the parking lot.(sign currently missing)
- How has the flow of the water from the spring changed since the earthquake? (sign currently missing)
- Estimate the depth down to the level of the spring water.
The above information was compiled from the following sources:
- Chapman, Chase, Youngs; Geophysical Survery, Paso Robles Geothermal Area, California, Part of the Resource Assessment of Low- and Moderate-Temperature Geothermal Resource Areas in California, Part of the Second Year Report, 1979-80 of the U.S. Department of Energy – California State – Coupled Program, November 10, 1980
- Informational Signs Posted at Paso Robles City Hall Parking Lot.