Elusive wetlands return to California's heartland
SRT preserves prove resilient amid historic flooding
By Gregory Liebau, SRT, and James Von Tersch, AmeriCorps
Much like the rest of California, SRT witnessed an immense amount of precipitation and runoff at our preserves over the winter! So much water flowed down local rivers and creeks that we were forced to close two of our public preserves for a brief period. Kaweah Oaks Preserve was partly inundated with floodwaters from Johnson Slough. Runoff at Homer Ranch Preserve caused so much erosion in the parking lot that cars could not safely enter.
Flooding on Johnson Slough receded after several days, and a crew promptly fixed the gulch in Homer’s parking lot, resulting in both preserves being reopened in time to enjoy the bountiful spring.
Fortunately, Dry Creek Preserve near Woodlake was not subject to any closures due to its higher ground. However, access to preserve beyond Dry Creek itself is still limited to those who don't mind wet feet as there is no bridge spanning the creek, restricting access to Steve Rice Lake and one half of the disc golf course. Crossing the creek at Homer Ranch Preserve is similarly limited despite decreasing flows since the last rainstorms passed. Dry Creek is primarily fed by rain given its headwaters at the foothill elevation, rather than the High Sierra snowpack that feeds the Kaweah watershed. This winter historic conditions forced postponement of several AC and Earth Academy field trips, as well as other preserve events.
While floodwaters damaged nearby homes and farms, no SRT preserve infrastructure was damaged. This included our recently completed event stage for The Grove at Kaweah Oaks along Johnson Slough's north bank. This area of Kaweah Oaks was almost completely inundated during the flood’s peak but survived the ordeal mostly unscathed. Not since the building of Terminus Dam on the Kaweah River in 1962 has the slough area seen flooding of this extent.
Since Kaweah Oaks' reopening, visitors may also have noticed that Deep Creek, flowing along KOP’s north end, has also been experiencing flooding. However, unlike Johnson Slough's, this inundation is a completely controlled project using large pumps feeding from Deep Creek into a basin purposely built within the perimeter of the Timothy Blaine Tashjian Cottonwood Fitness Trail. The former plum orchard is now a stand of cottonwoods that seeded naturally, making this a somewhat effortless restoration for this innovative multiuse area.
The flooding, whether uncontrolled or controlled, has provided numerous benefits to the preserve’s ecosystems as well as serving as purposeful groundwater recharge. The oaks, sycamores, and other riparian species have undoubtedly benefited from the much-needed water. While some gophers, squirrels, and cottontails have been flooded out of their burrows, the water has invited species of waterfowl that are not commonly seen here. At KOP, the floodwaters have mostly filtered through the ground, giving further credibility to the preserves ability to recharge groundwater. It is possible that we may see similar flooding on Johnson Slough now that the record-breaking snowpack in the Sierra Nevada mountains has begun melting, so keep an eye on our website for any possible alerts or closures.
Travelers making their way down State Route 137 between Tulare and Lindsay probably noticed that the road was closed directly in front of the James K. Herbert Prairie Wetland Preserve. The road closure was due to flooding from Outside Creek, which also filled the artificial slough near the preserve’s northwest corner. The vernal pools were thriving on the preserve this season due to the continuous rains, with vernal pool fairy shrimp populations having been sustained for several months. Amphibians, such as western spadefoot toads, filled the pools with thousands of tadpoles, while waterfowl and shorebirds were frequently seen foraging in and alongside the pools. Unfortunately, due to the flooding of SR 137, the Wildflower Walk at the Herbert Preserve was postponed until April. It ended up being a wonderful event nevertheless due to persistent mild weather and wet conditions, and nearly two hundred members of the public joined SRT staff to admire the preserve’s flora and fauna.
Flooding along the Tule River around Springville resulted in several of the roads leading to the Blue Oak Ranch Preserve being closed for a short period of time. If you are planning on entering at the Harris Road entrance, please be aware that there is some residual flood damage to the road around the bridge over Dennison Creek and if you are driving a large vehicle, you may want to proceed with caution. Otherwise, this past spring was a wonderful time to visit Blue Oak Ranch Preserve as the wildflower season in the foothills was marvelous and there was plenty of water in the creeks and ponds.
While the wet season of 2023 is behind us and temperatures are rapidly rising, right now is still a great time to visit our preserves and to experience lush vegetation and an abundance of shade under native trees of all descriptions. But keep an eye out for rattlesnakes and all of the other usual suspects – be respectful of nature and remember that even SRT’s well-maintained preserves are still wild places!