What is the Circulation System?
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 figure below shows the culvert pumps, highlighted in yellow, and the section of the circulation system that was activated in 2020, also highlighted in yellow. Pumps C4-C6 and the smaller 300 HP pump in the pumphouse were utilized to create circulation within the West Lagoon. Water taken in from the intake at W was discharged at 1. All other valves for other discharge areas along the system were closed while the system was active. Water samples were taken from sampling sites marked with red circles.
Tahoe Keys and Lake Tahoe Flow Term Model
The below photo represents both the surface and groundwater natural flow between the Tahoe Keys, Lake Tahoe, Lake Tallac and natural marsh lands around the Tahoe Basin. The circulation system is essential in creating flow of the waters within the Keys lagoons thus eliminating a stagnant environment which allows easy growth of auqatic invasive species due to nutrient dense, shallow, and warm waters.
Circulation Treatment System Design
•Entire lagoon turnover is around 3x per month
•Circulation Flow Capacity: 40M gallons per day
•Treatment Capacity: 10M gallons per day
Pre-/Post-Keys/Pope Beach Development
With the development of Pope Beach, the road that was created, distrupted the natural ecosystem and generated an issue with the filtration system of Pope Marsh.
1952 Pre-Pope Development
Source: Green, 1998
1971 Pope Development
Source: Green, 1998
