The San Antonio Riverwalk was a popular theme during the Chamber of Commerce’s visioning session several years ago. The Riverwalk is an example of maximum development that also requires maximum flood control measures to protect it.
For Cumberland, it is not really a viable alternative. However, other flood plain approaches that allow for flooding such as in Reno or Houston are more viable alternatives.
In March, I did a presentation at an international conference in San Antonio on the behind the scenes tour of the Riverwalk. I began the presentation by raising the question why someone from Frostburg, Maryland was presenting on the Riverwalk in San Antonio.
The simple answer is that it is my area of professional expertise. Most people visit the Riverwalk, enjoy its many treasures, and leave thinking how nice it would be to duplicate the Riverwalk in their city.
Unfortunately, they leave without understanding how the flood control infrastructure makes the Riverwalk possible. My presentation provided that understanding.
Rivers flood. It is axiomatic. It is not if, but when they will flood. The Potomac River is no different from the San Antonio River. Without extensive flood control measures, the San Antonio Riverwalk would not exist as we know it today. The river forms a large oxbow through downtown San Antonio.
It is not unlike the oxbow the Potomac River makes as it touches Cumberland. The first flood control measure taken in San Antonio was to dig a bypass canal with floodgates to avoid the oxbow.
Next, the Army Corps of Engineers bored a 24-foot diameter tunnel three miles in length 150 feet beneath San Antonio. A reverse syphon, it is designed to accept one-half the flow of the worst known flood.
Completed in 1997, it cost $111.4 million. Also, when the river flow drops below 50 cfs, flows are augmented by recirculating water back through the siphon.
For Cumberland, the bypass canal and tunnel concepts could be combined where a tunnel is bored through the mountain between Ridgeley and Carpendale.
Cumberland uses traditional levees to solve its flood control problem. Utilitarian, they do the job. They are planted with grass. Trees and larger vegetation were removed to increase the flow rate past Cumberland. It is the standard no frills flood control design.
The design has two unintentional consequences. Visually, the levees divorce the river from the city. Second, the mowed levees and the channelized river discourage use. To further discourage use, no trespass signs are even posted on the levees.
Alternative flood control approaches are available. These approaches allow for low impact development within the flood plain. The Army Corps of Engineers is slowly beginning to recognize these approaches. The whitewater course in the Reno whitewater park is designed to washout during floods.
In Houston, the Buffalo Bayou Trail is designed to be completely submerged during their frequent floods. Galvanized steel is used extensively in the bridges, railings and other fixtures that become inundated. Electrical fixtures are designed to tolerate flooding and panels are placed on high ground.
Trees, walkways, and trails lace the flood plain and are designed to survive floods. The benefit is that the flood plain has become a viable recreational park for citizens. Also, flood control has been enhanced.
The Riverwalk concept in San Antonio is not really feasible for Cumberland. Developmental costs are prohibitive. Developing recreational facilities like a whitewater park designed to be periodically flooded are a much better alternative.
In addition, a whitewater park would provide an attraction for people to visit the river and it would help reconnect the city with the river.
Robert B. Kauffman, Ph.D.,
Professor and chair, Department of
Recreation and Parks management
Frostburg State University