SAND BAR RESTORATION
By Dr. Joan Mossa, University of Florida
Late Spring 2019–The UF crew (Drs. Joann Mossa and Yin-Hsuen Chen, Ph.D. students Charles Wu, Amobi Amanambu,  went out to Bristol to meet with Dan Tonsmeire (6/2/19) unsure of what we would find. Our last visit in early November 2018 had been somewhat promising as the vast majority of our plantings had survived Hurricane Michael, which brought tremendous devastation to the region. The willows withstood the same high winds that blew down millions of trees as well as a hydrograph bump just above 43,000 cfs associated with flow releases upstream. Although the plantings survived Michael, most did not survive the events of winter. By January, flow levels reached nearly 100,000 cfs with water levels 7 feet higher than Michael. About every three years, flows reach this level at Blountstown, so this was a higher than average maximum flow.
We found only two plantings that survived, but are hopeful next year will have a better survival outcome based on long-term flow and stage range statistics and our learning. One positive is that we are planting earlier, which means that the roots will have more time to establish. A second sign that willows could have better success in establishing is that the flow levels this June are less than those last June, which could mean a drier year overall. If this year is similar to last, we realize that a 20-foot change in stage elevation across the year may be hard for willow survival until the plantings become deeply rooted. For this reason, we might add a comparison downstream site that has less stage variation, knowing that last year Wewahitchka had a less severe 13-foot stage change range.
One uncertainty and concern is the presence of vehicle tracks on all three of the sand bars near our planting sites. We will select less trafficked areas where people are less likely to drive over young plantings. Although we are unsure how our plantings disappeared, whether by Mother Nature or human nature, we are going to try again and stay hopeful and work hard for a positive outcome and more learning. So, during this first excursion, we collected eight buckets of willow cuttings to start the new planting year off with a bang. Georgia Ackerman is babysitting our willow cuttings, helping their roots grow while soaking between trips to increase their chances of survival.
SAND BAR RESTORATION
Summer 2019–Over the summer, following our initial survey in June, the UF crew (Drs. Joann Mossa and Yin-Hsuen Chen), Ph.D. students Ali Alruzuq and Amobi Amanambu took trips to Bristol and Wewahitchka. Riverkeeper Georgia Ackerman joined us for all trips, and volunteer Rick Zelznak also came with us on multiple days.  Due to minimal survivors from last year upstream, we modified our planting strategy to increase our chances of success. The hydrograph last year had several rises and falls, and a severe wind event, Hurricane Michael, which brought tremendous devastation to the region. By January, flow levels reached nearly 100,000 cfs and annual stage changes of 20 feet at Blountstown. Not knowing what the hydrograph would do, we added some planting sites further south on the river where stage variations are generally less (~13 feet last year). This year, we have plantings on five bars, three downstream of Blountstown at RM 76.5, RM 75.4 and RM 73.8 and two located 2 to 5 miles upstream of Wewahitchka at RM 46.6 and 43.5. Two of the bars had over 450 plantings apiece; one had the least human activity (RM 73.8) of the upstream bars, and one downstream chosen because it had little vegetative regrowth since dredging ended in 2001 (see figure of bar at 43.5). The other three bars had between 50 and 150 plantings. So far, this has been a drier summer overall lower flow levels. Some plants did not survive because of feral pigs and vehicles, and others will not survive the droughty conditions. Yet, we found that some the cuttings planted earlier in the summer are growing well and increasing in size over the growing season (see Figure).
We left more than 150 willow stakes to soak under the care of Georgia Ackerman until October when RiverTrek 2019 begins. During this event, 17 volunteer kayak paddlers will travel along the river for 5 days. One of the sites that they will visit is the highest dredge spoil mound on the river, known as Sand Mountain about 5 miles south of Wewahitchka. Erosion of this steep site has contributed large quantities of sediment to the river, making the adjoining river quite shallow. A vegetative buffer along the edge of Sand Mountain should reduce the quantities of sediment entering the river at this site. Volunteers will plant these cuttings here, and improve the buffer that nature is starting. There is uncertainty about what the hydrograph will do this winter, but due to our learning last year we now have more sites, and a greater variety of sites within bars and along the river corridor. We will continue to monitor, learn and do our part to help restore the river with Riverkeeper with our funding from the EPA Gulf of Mexico Program.
