The San Marcos River Foundation attended the Work Session October 15 regarding a concept proposal for a county park around Cape Road. There are many positive aspects to the plan. First, the county has spurred a much-needed conversation regarding what to do with the river park land on the east side of San Marcos. The proposal includes 2 new locations for parking away from the river, recognizes pedestrian safety concerns on Cape Road, could potentially incorporate the pond east of Cape Road for additional park space, has educational opportunities and identifies potential river access points. We are pleased to see the city finally addressing park solutions in this area but we need to point out our concerns:
Mitch Wright (the consultant hired to create the plan) mentioned several times that the water level in the mill race needs to be raised so that people could get in and out easily and reduce stagnation. This involves even more water being diverted away from the natural river channel which is quite alarming. Even during high flow years stagnation occurs, and water rarely, if ever, reaches the sidewalk.
The plan specifies that the dam would be built to its original form, a Crib Dam, allowing more flow through it. Increasing flow through the crib dam and putting more water in the mill race does not seem feasible. There is a finite amount of water available to go either direction. Especially in low flow years.
The plan located 3 major swimming spots: one above the dam, one in the mill race and one where the mill race empties back into the river. Some have said that if the dam were removed, the river channel would not be suitable for swimming. The thing to remember is that rivers have natural riffle-pool sequences (based on the grade of the river bed at each location), and restoring the river channel will allow those processes to continue. This happens all along the San Marcos River. There could be access points built to the suitable swimming spots that the river would naturally create if the dam is removed.
It was mentioned that the county park would not be a tubing park; that it would be for hikers, swimmers and kayakers. There are no laws that preclude tubing on Texas waterways. There is a delicate balance with the number of people in any stretch of river and there are definitely places on the river where this balance is not being met. The county proposal to discourage tubers may not feasible.
There were no clear answers about who would pay for the management and maintenance of the park. Rebuilding the dam will be costly, and the county or city will have to maintain and repair it after each flood. We are currently seeing this at Rio Vista. We think these details need to be addressed. We also want to have the county’s position clarified should US Fish and Wildlife Service (USFWS) and the Army Corps of Engineers recommend removing the dam. It is not clear if the county will want to be involved in developing this park or if it is contingent on having the dam rebuilt.
It was stated multiple times in the work session that USFWS was unsuccessful in getting a permit to remove the dam. What actually occurred was that the deadline passed to use the grant funds. Those same USFWS grant funds could be applied for again.
We agree that USFWS, along with the Army Corps of Engineers will be the permitting agencies for the dam. Permitting will determine everything. Council asked that city staff find out the opinions of those agencies before deciding which way to go regarding the dam. If those questions could be answered without a full application, then the information obtained could prevent wasted time and money. Our concern is that there won’t be an answer before an official permit is requested.
The city council was very interested in working with Hays County on a plan, since the parks really do need to be addressed, but the council is still not united on whether to keep the dam.
Why is Capes Dam Different than Other dams on the San Marcos River?
We get this question a lot. Not all dams divert water in such large amounts as Cape’s Dam.
There is approximately 3500 feet of natural river channel that has less water flowing in it because of the diversion to the mill race, starting at Capes Dam and finishing where the mill race dumps back into the San Marcos River. This is 2/3 of a mile that is deprived of its full flow.
1/3 of the River’s water is diverted to the mill race during normal flow times. That percentage goes up as the water drops. This is very concerning for future droughts we will have.
In addition, water in the mill race seeps under Thompson’s Island, compromising its integrity over time and during flood events.
Ultimately we want to see the park area east of i35 open to the public. There need to be adequate amenities including restrooms, parking and patrolling. This can be accomplished with the health of the river in mind.
