Check out all of the AIS projects below!
Tahoe Keys Bubble Curtain
The Tahoe Keys Bubble curtain was installed in 2018 to create a barrier that prevents AIS fragments from entering Lake Tahoe. During 2020 the TKPOA AIS program installed a new 7.4 horsepower compressor that provides more air flow to the bubble curtain, creating a better barrier. This project was funded in part by the League to Save Lake Tahoe.
For more information on the Bubble Curtain click here
Instructs boats to back up to dislodge vegetation fragments from their props and rudders.
The TKPOA implemented the Boat Back-Up Station in 2016 and has continued to improve on the design. The system now utilizes the combined strategies of the Boat Back-Up station, bubble curtain, bottom barriers and seabins. The Boat Back-Up station notifies boaters to back up, ensuring that weeds caught on their props and rudders are dislodged before they enter the lake.
Synthetic mats are installed to block out sunlight and smother aquatic invasive weeds on the floor of the lagoons. These barriers are installed at locations requested by homeowners who volunteer for this program. The Association is allowed a total of five acres of bottom barrier coverage.
Check out the 'Take Action' page to learn how to sign up for a Bottom Barrier!
Laminar Flow Aeration (LFA)
The TKPOA currently has 2 LFA sites, one adjacent to Christie Dr. North of Venice Dr and another in the West Channel entrance. LFA involves bubbling air through several small diffusers on the bottom of the lagoons. The air bubbles create circulation, increasing the amount of oxygen at the bottom of the lagoons, which promotes microbial activity in the sediment and “muck”. This change is intended to make the nutrients less available for the weeds and algae, which should reduce the rate and amount of weed growth in the area of the LFA test. Status: TKPOA has received financial support for this project from The League to Save Lake Tahoe.
This project was funded in part by the League to Save Lake Tahoe.
For more information on LFA click here
The AIS staff map plant density in the Tahoe Keys Lagoons. It is done using an HDS 7 Lowrance system with a HDI 83/200 Transducer mounted on the AIS boat and Biobase software that determines plant density based on the structure scan produced by the Lowrance system. These scans help the WQ department determine which areas have the worst infestation.
Floating Treatment Wetlands
This technology uses native wetland plants on a floating matrix. The roots extend into the water providing a very large surface area through which nutrients are absorbed and removed from the water. The islands may also be deployed with fine-bubble aerators to create water circulation to push more water through the root system. In the summer of 2020 the TKPOA installed 15 Floating Islands in Lake Tallac to address its efficacy in improving water quality.
Circulation system moves water to disrupt algae proliferation. The Tahoe Keys was constructed with a water circulation system to keep water in the lagoons as clean as possible. This system used coagulation to reduce Total Dissolved Solids (TDS) and decrease turbidity helping keep the lagoons relatively clear.
The TKPOA installed a sea bin at the edge of the channel near the bubble curtain to automatically collect fragments that are stopped by the bubble curtain. This crew collects fragments, empties the sea bins and records the volume and species of the weeds that were collected. This gives the TKPOA a quantifiable number for the volume of weeds that the system prevented from entering the lake.
Best Management Practices
The TKPOA is developing Best Management Practices (BMP) to prevent runoff from houses and yards that may contain nutrients that would fuel vegetation growth.
Stormwater and erosion control BMPs are retrofit measures required on all private properties in the Lake Tahoe Region to control erosion and infiltrate stormwater before it leaves the property. BMPs are proven to prevent sediment, nutrients, and other pollutants from entering waterways. BMPs include pollutant source control measures which reduce the amount of pollutants present and hydrologic source control measures to direct stormwater and snowmelt runoff so that pollutants are filtered out and prevented from entering surface water.
Harvesting is the primary control method available to the Tahoe Keys today. Throughout the summer months the TKPOA operates harvesters that remove vegetation from designated sections. During the months of July and August, harvesters focus on navigation lanes so boaters can travel through the lagoons. During the last few weeks of the harvesting season harvesters focus on removing as much vegetation as possible by harvesting the entire section between homeowner docks. This helps to reduce available nutrients and may possibly help reduce vegetation growth the following season.
Lagoon Friendly Landscaping
TKPOA encourages phosphorus free fertilizers to decrease available nutrients for aquatic macrophytes.
The Lake and Lagoon Friendly Landscaping educational campaign was initiated in 2017 to annually inform property owners on best practices to reduce runoff and pollutants through better landscaping techniques.
Most landscaped areas in the Tahoe Keys Facility are under the control of individual homeowners who may maintain their properties or may contract private landscaping companies for maintenance. TRPA acknowledges and tracks BMP installation by inspecting and issuing a BMP Certification or Source Control Certificate (SCC) letter to the property owner. A BMP Certificate certifies that the BMPs are properly installed and functioning on a property.
Tahoe Keys Complex Restoration
The Tahoe Resource Conservation District (TRCD) has funded diver assisted hand pulling within the Tahoe Keys Complex along with the East and West Channels. This project was started in 2020 and will continue into 2021.
For more information on diver assisted hand pulling click here
This method is currently being tested at the Lakeside Marina. Depending on the outcome of the UV light test, this method could also be one of TKPOA’s many tools in their integrative approach to managing the invasive plants.
Diver Assisted Hand Pulling
Divers pull plants by hand and put them into a suction hose to be collected from staff on the surface. Diver assisted hand pulling was conducted throughout the Tahoe Keys Complex outside of the West Channel in 2020 and is planned for the East Channel in 2021.
For more information on diver assisted hand pulling click here
Ultrasonic technology has been proven to reduce algal blooms in other waterbodies. This technology could be used to prevent and disrupt algal blooms inside the Tahoe Keys Lagoons.