Siltation rates at Salt Creek WMA are high due to surrounding agriculture and return irrigation water. The spring of 2017 also increased sedimentation rates drastically due to a 30 year flood event. Increased sediment in the main water delivery channel to Salt Creek has caused interruption of water delivery systems, inability to properly drain the unit, and raised the pond soil surface making it difficult for hunters and boats to access. Several years ago, a number of nesting islands were formed in Salt Creek's main impoundment. Unfortunately, vegetation never established on some of these islands and many of them have eroded away. In some cases the islands are less than half of what they once were. These islands are important for nesting birds as they provide sanctuary from predators.

Dredge and remove sediment from approximatly, 7,000 linear feet from the main channel and the north bay of Salt Creek WMA. Restore water delivery capacities and the ability to drain the unit. Increase access for boats and walk-in hunters. Restore islands that are used for nesting and establish emergent vegetation around the islands to prevent further erosion.

The threats and risks of this increased sedimentation includes; 1) decreased water delivery downstream. More water is being held upstream and not making its way to Salt Creek Bay. 2) Increased sediments promotes easier establishment of unwanted vegetation (cattail) and noxious weeds (Phragmites). If this continues, water delivery capabilities will be hindered further. 3) Access by hunters is increasingly difficult. 4) Increased sedimentation does not allow mangers to drain/drawdown the area properly. Drawdowns are extremely important for wetland mangers. Drawdowns are used to protect infrastructure from ice damage, concentrating carp for rotenone treatments, and releasing nutrients for increased pondweed production. 4) Islands that are used by nesting birds have eroded away displacing these birds to other areas that are more susceptible to predators.

This project is related to the purpose of Salt Creek Waterfowl Management Area as stated in the habitat management plan:To preserve, restore, and enhance both aquatic and terrestrial habitat for wildlife; increase wildlife populations to meet wildlife management objectives; conserve, protect, and recover sensitive wildlife species and their habitats; protect cultural resources; and provide for recreational opportunities that are compatible with the purpose of upland and wetland ecosystems. In relation to the WAP, Objective #1 for Sediment Transport Imbalance Opportunities are found and taken,to modify or remove reservoir infrastructure, or modify outflow management, to simulate or return natural sediment transport. This project meets this objective by removing sediment that has accumulated over the years and restores the channels to a more natural flow. Also in relation to WAP is Objective #2 for Droughts Aquatic SGCNs and key habitats persist on the landscape, despite increasing drought conditions. Drought conditions over the past several years has made it imperative that the WMA's have properly functioning water control structures and delivery channels to maximize water deliveries in order to maintain key wetland habitats. Actions that this project will address include; 2.3.6 Restore aquatic habitat complexity Also in relation to the WAP are: Invasive plant (Phragmites) dominance/presence is reduced or eliminated in locations or habitats where such an outcome is realistic (ecologically and economically).2.2.2 Survey and inventory established and new populations of invasive/problematic species. 2.2.3 Eradicate established populations of invasive/problematic species. 2.2.4 Contain established populations of invasive/problematic species. 2.2.9 Avoid establishment of new invasive/problematic species through education, planning, management, and/or regulation. Increased sediments allow for invasive plants such as Phragmites to establish and expand through areas that were once open water habitats.

Not applicable

Overall water quantity will not be increased, but water quantity downstream of Salt Creek WMA into Public Shooting Grounds WMA should increase slightly once sediment is removed and water is allowed to flow more freely. Furthermore, increasing water flow through this area will help increase dissolve oxygen levels, allow nutrient rich sediments to flow through the wetlands instead of being deposited in one area, and allow for better water filtration. Water quality will also be increased by giving managers the ability to drawdown impoundments and flush out high nutrient and/or contaminated sediments.

The archaeologist will be consulted for this project. However, the areas have already been disturbed in the past. 6 NEPA, This activity is covered by categorical exclusion.

This project will be put out for bid according to state purchasing guidelines. Managers will drain the impoundment starting in late May. By early July, soils should be dry enough for equipment access.Heavy equipment such as, trackhoes, agricultral scrapers, and dozers will be used to remove material. Material will then be transported and placed on and next to islands that need to be restored. Hay bales will be place on the side of the islands directly adjacent to the excavated channel. This will help with erosion and plant establishment. The following spring, WMA personnel and volunteers will use airboats and john boats to transport excavated bulrush rhizomes to plant around the islands.

Photos will be taken throughout the project. Monitoring of increased sediments in the northern portion of the channel will be monitored on a yearly basis. It is estimated that small-scale channel cleanings will be needed every 2-3 years in order to maintain this projects objectives and increase it's longevity. Vegetation establishment will be monitored through photographs and ocular estimations during routine WMA activities (i.e. census, weed spraying, duck and goose banding, etc.)

Delta Waterfowl

Due to its proximity on the landscape, Salt Creek WMA is prone to high sedimentation rates. Future management will consist of monitoring the main channel and implementing small-scale channel cleanings more often (2-3 years) using the waterfowl maintenance crew. Also, once the main channel through Salt Creek Bay is re-established, drawdowns should help to pull some of the sediment out of the channel. This project will benefit future management practices on both Salt Creek and Public Shooting Grounds WMA's by increasing water flow to downstream areas making it easier for managers to control downstream pond levels and water outflows that are more beneficial for wetland flora and fauna.

This project will help sustain hunting opportunities at Salt Creek WMA. The channel will be more accessible by waterfowl hunters, and the improved islands and water delivery systems will make it easier for managers to improve and maintain quality wetland habitat.

07/01/2019

06/30/2021

2021

During the winter of 2020, the bypass canal at Salt Creek WMA was repaired in order to fix damages that were allowing for water to enter the project site the previous summer. In the summer of 2020, the site was dry and work dredging the channel began in September. Agricultural scrappers, tracked skidstears, and small track hoes were used to dredge the channels. Material from the dredging was used to repair and reshape 18 islands that had eroded away over the years. Two main channels were dredged at a depth of 2' and width of 12' with a 3:1 slope from the bottom of the channel to the top of the existing pond floor. A total of 11,900' of channel was dredged. Islands varied in size and were built with a 4:1 slope to insure shallow water around the island which should allow for emergent vegetation to establish. A 2' wide dirt berm was constructed at the leading edge (closest to channel) to help with erosion control and facilitate better plant establishment. Wetland plant plugs, bare root stock, and wetland sod mats, were planted along the edges of most islands. Plant material consisted of three-square bulrush, alkali bulrush, hardstem bulrush, and salt grass.

In order to start this project, Salt Creek WMA needed to be drained in order to dry the site out for heavy equipment. Unfortunately, due to unforeseen damages (rat holes) in the bypass canal, we were unable to dry the area out during the summer of 2019. During the winter of 2020, the waterfowl and habitat maintenance crew worked diligently to fix the bypass canal and plug any holes. Managers were able to dry the site out in 2020 and construction started in September. Two agricultural scrappers were used to dredge the channels and place material on the islands. Skidstears and small excavators were used to shape the islands and dirt berms around the leading edge of the islands. Construction crews completed the project and managers started to re-flood the project area the first week of October. In the spring of 2021, a number of different species of wetland plant material was planted around the edges of most islands to help facilitate plant growth and decrease the chance of these islands eroding away.

Future management will consist of planting grass species on the top of the islands in the spring of 2022. We will the assess the success of this years wetland vegetation planting and possibly plant some more plugs and bare root stock of bulrush species if necessary. Due to its proximity on the landscape, Salt Creek WMA is prone to high sedimentation rates. Future management will consist of monitoring the main channel and implementing small-scale channel cleanings more often (2-3 years) using the waterfowl maintenance crew. Additionally, know that this project is complete, annual winter drawdowns should help pull some of this sediment out of the system. Managers are also discussing the installation of a sediment retention pond near the north end of the property where 90% of the water enters Salt Creek WMA.