The San Marcos River bubbles to life from the San Marcos Springs at Aquarena Center (formerly Aquarena Springs) on the campus of Texas State University (formerly Southwest Texas State University) in Hays County and flows about 85.5 miles through Guadalupe and Caldwell Counties to the confluence of the Guadalupe River in Gonzales County. In practical terms, recreational use of the river is usually limited to about the upper 16.5 miles between Old City Park in San Marcos down to FM 1977, just above Staples Dam, but can be paddled all the way to the Guadalupe River. This report will cover the 40.5 miles from Luling down to US Highway 183 in Gonzales.
Between SH 80 in Luling to the Guadalupe in Gonzales the San Marcos flows about 36 miles, after which boaters must paddle another 4.5 miles on the Guad to the US Highway 183 bridge. Just above the take-out is the last mandatory portage at Gonzales Dam. The river is a gentle, Class I flatwater run that throws numerous portages in the form of dams and log jams at you from beginning to end. The river is fed by several creeks and springs that drain into it along the way. It teems with wildlife that includes thousands of turtles (literally!), snakes (including water moccasins), Great Blue Herons, egrets, turkey buzzards, feral pigs, beavers, squirrels, raccoons, armadillos, cows, horses and other species. The beautiful stream is verdant with a wide variety of native plantlife including river lilies, pecan, oak, sycamore, elm, peach and willow trees. Fishlife is excellent, and anglers with a valid Texas fishing license can wet a hook for yellow and channel catfish, Guadalupe, spotted and largemouth bass, perch, sunfish and bream, among others. This run begins in Caldwell County, then flows through Guadalupe County to its conclusion in Gonzales County.
Caldwell, Guadalupe and Gonzales Counties in the Southwest Texas Hill Country, near New Braunfels and Austin. The river flows from Aquarena Springs on the campus of Texas State University in San Marcos down to the confluence of the Guadalupe River near Gonzales about 82 miles below its headwaters.
San Marcos 23 miles; New Braunfels 29 miles; San Antonio 61 miles; Austin 46 miles; Houston 138 miles; Dallas 253 miles; Oklahoma City 462 miles; Little Rock 566 miles; Kansas City 741 miles; Albuquerque 750 miles; Denver 1,011 miles; Grand Junction 1,131 miles; Salt Lake City 1,267 miles; Phoenix 1,067 miles (all distances are approximate and depend upon starting point, destination point on the river and route taken.)
The water quality in the San Marcos River is generally very good, running clean and clear most of the time, but getting murkier as you move downriver. However, it will become muddy after recent local rainfall, and may become cluttered with debris during flood stage conditions. At a near constant 72 degrees the San Marcos is very pleasant for paddling year around. The springs at the headwaters generally provide adequate flow for a river trip most of the time. Below Staples Dam are a number of small to medium sized dams that must be portaged, as well as numerous log jams that almost always must be portaged.
The San Marcos is not as seasonal as most Texas rivers, and can generally be enjoyed anytime of year. Proper winter wear is recommended for cold weather paddling and you can expect hot temperatures from June through September, so dress accordingly and take along sunscreen and plenty of liquid refreshments during hot summer months.
The San Marcos River is characterized by numerous small to medium sized dams, most of which must be portaged. Strong hydraulic currents are at the bottoms of most drops over dams, and these should generally be avoided. Downed trees in the river channel also mandate careful maneuvering to avoid, especially after a flood. When in doubt - ALWAYS SCOUT! Summer temperatures should be considered a hazard if proper precautions are not taken. Always have protective clothing, sunscreen and plenty of non-alcoholic liquids to prevent dehydration.
Two dams merit special mention, because both are killers that have claimed many lives over the years, including those of people who were very experienced on this river. Ottine Dam, at about 12.5 miles below Luling City Park should be portaged on river left at low to normal water levels, and on river right at high flows. Do NOT even think about trying to run this dam. If the drop does not kill you, then the hydraulic at the bottom will! Gonzales Dam on the Guadalupe River, about 1.5 miles above the take-out, must be portaged on river right. This is another killer dam if you should run it, and survival is doubtful, though it would probably be worse than being killed. In both cases the river banks are steep and frequenty slick with mud, especially after recent rainfall, making egress very difficult at best. At both dams take out well above them to avoid being swept over, though flows are not strong except in high water conditions. These portages are difficult, and not for recreational boaters lacking sufficient river skills to negotiate deadly hazards. There is also a low-water bridge at about 21.5 miles below Luling that usually must be portaged, though it can sometimes be run if the water is high enough to otherwise be dangerous. At low or normal flows this bridge can pin and wrap a boat, injuring or killing a boater.
Paddlers should always pack gear in drybags and securely tie in everything that want to keep and keep dry. There are plenty of submerged logs, log jams and stealthy currents that can capsize an unwary paddler, sending him or her swimming. I hit a low water bridge at about 1,900 cfs and did a passive swim for nearly 3.5 miles before another boater caught up to me - there was nowhere to exit the river at that flow rate until I hit an eddy downriver. Fortunately, the boat washed out at about the same place where I was able to exit the river.
Luling City Park off SH 80 at 0.0 miles; Palmetto State Park on river right at about 13.0 miles; Low-water bridge below the high bridge between FM 2091 and US Highway 183 southwest of Slayden at about 21.5 miles; US Highway 90 Alternate bridge west of Gonzales at about 31.5 miles; US Highway 183 bridge, on river right, adjacent to Independence Park in Gonzales at about 40.5 miles. There are no other access points on this reach of the San Marcos and Guadalupe Rivers. Access is adequate at most crossings, but the availability of public parking is very limited. Please be considerate of others when accessing the river, and always park your vehicles where they do not block river access for others. Never park on or enter private property without securing permission from landowners.
Palmetto State Park (reservations through Texas Parks and Wildlife Dept.). There are at least two commercial campgrounds available along the San Marcos River at Martindale.
TG Canoe & Kayak (512-353-3946), located at 402 Pecan Park Drive, San Marcos, offers canoe and kayak rentals and sales, gear and accessories sales, repairs and outfitting, and private boat shuttle services on the San Marcos River in Martindale. TGCK also offers canoe, kayak and tube rentals on the San Marcos River in Luling. Spencer Canoes (512-357-6113), located at FM 1979 and the San Marcos River in Caldwell County, offers canoe rentals and sales, shuttles, custom boat building and rigging (including Texas Water Safari boatworks), repairs, certified canoe instruction and other services on the San Marcos River. TG Canoe & Kayak - Austin (512-473-2644) offers canoe and kayak sales, accessories and gear sales, and custom outfitting. There are other commercial outfitters offering rentals, shuttles and river information located along the San Marcos River between the Town of San Marcos and the Town of Martindale.
The San Marcos River will ALWAYS be one of my favorite rivers because of its natural, undisturbed beauty and great water that almost always flows at about 155 cfs (minimum) from the spring where it forms at Aquarena Springs in the Town of San Marcos. The water is a constant 72 degrees, which is very comfortable on a hot Texas summer day, and not too bad on the ten or so days a year when Texas does NOT have summertime temperatures. Having said that, this is probably the most dangerous flatwater river I have ever paddled. Snakes are there, but I have never known of anybody having a problem with them, and do not know of anybody being bitten. Fire ants are another matter, especially after a flood! They DO bite, and bite frequently. Log jams are the biggest obstacle to navigation, often causing boats to capsize or forcing portages where they are not convenient. In the many times I have paddled the "Come and Take It" marathon canoe race on the Guadalupe River at Gonzales from the K5 dam, past the San Marcos confluence to the US Highway 183 take-out, I have never had an accident or injury, but portages have cost me over an hour to 90 minutes of lost time getting myself and my boat out of the river, around the obstacles and back into the river. The necessity of recognizing and portaging those dams at Ottine and Gonzales cannot be over-emphasized - they WILL kill you if you run them! This is a very scenic river along which are many old homesteads, some dating to before Texas became a nation in 1836. If you are a recreational paddler, then go to San Marcos and paddle the upper 16.5 miles of this river, but if you have the skills and the desire to paddle where few others dare to go (except during the Safari), then this reach of the San Marcos River will be a place where you need to dip your paddle.