Biological Opinions - Bureau of Reclamation

1. The A Canal has six headgates that are maintained. The A Canal headgates are only
operated and exercised when fish screens are in place. However, if the fish screens fail,
the A Canal will remain operational until the screen is repaired or replaced. Screen
failure occurs under certain circumstances, such as when water pressure is too high, and
the screens break away so as not to ruin the screen or other infrastructure. Fish screens
typically fail once or twice a year during normal operation, and Klamath Irrigation
District is notified by means of an alarm. Fish screens are repaired as quickly as
practicable.
2. The A Canal headgates are typically exercised in February or March, and in October or
November when bulkheads are in place and the A Canal is drained and empty.
3. The Lost River Diversion Channel diagonal gates and banks are scheduled for inspection
every 6 years. Inspection is conducted during the winter, which requires drawdown of
the Lost River Diversion Channel. However, drawdown of the Lost River Diversion
Channel leaves sufficient water to ensure that fish are not stranded. The appropriate
water levels are coordinated between O&M staff and Reclamation fish biologists.
Biological monitoring is incorporated to ensure flows are adequate for fish protection.
4. The Ady Canal headgates are exercised annually, typically between July and the end of
September.
4.3.1.6 Fish Screen Maintenance
The A Canal fish screens have automatic cleaners. Cleaning is triggered by timing or a head
difference on either side of the screen. Automatic cleaner timing intervals are typically set at 12
hours, but may be changed as conditions warrant.
Fish screens at the Clear Lake headworks are cleaned before the irrigation season and when 6 to
12 inches (in) (15 to 30 centimeters (cm)) of head differential between forebays 1 and 2 is
observed. The frequency of cleaning is dictated by water quality and lake elevation, and varies
from year to year. For example, in 2009 the screen was cleaned every other day from late June
through September. In 2011 cleaning was not required during the irrigation season. An extra set
of fish screens is used while the working fish screens are cleaned to prevent fish passing the
headworks. Cleaning the fish screens at Clear Lake may take up to 10 hours. Fish screens are
not used during flood releases when Clear Lake elevations are greater than or equal to 4,543.00 ft
(1,384.71 m), but the maximum lake elevation observed during the POR for this water body
(4,539.55) is nearly 3.5 feet (1.1 m) below this elevation.
4.3.1.7 Fish Ladder Maintenance
Link River Dam fish ladder O&M includes exercising both the headgate and the attraction flow
gate. Gates are exercised twice a year in February or March and in November or December.
Exercising the gates typically takes approximately 15 minutes. This activity includes monitoring
by Reclamation biologists.
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