River Regs Flashcards
Purpose of Old Hickory Dam instructions for reservoir regulations
1 - provide instructions to the operators and disseminating pertinent hydrometerorlogical info
2 - presents the water control plan for normal and emergency regulations
3 - provides standing operating procedures which are in effect when there is a loss of communication with district office
Responsible agencies
project owner - USACE operating agency - USACE regulating agency - USACE hydropower marketing agency - SEPA hydropower scheduling - TVA
Water control plan 3 primary objectives
provide 9’ slackwater pool for nav from OLD to COR
hydropower
provide a small amount of surcharge storage to mitigate the effects of the reservoir by replacing natural valley storage lost due to the impoundment
primary water management functions of operators
insure headwater and tailwater levels are above minimum allowable
see that changes in generation do not exceed 1 unit/hr
that machinery is operated within allowable limits
what are the 3 zones of the pool
inactive pool - bottom of lake to 442
power pool - 442-445
surcharge pool - 445-450
hydropower generation increase/decrease is limited to
one unit per hour
what is the elevation and cfs with one unit running
385 6000CFS
Why do we need to maintain 1000CFS
waste water assimilation in the nashville area
periods of zero release are restricted to what
no more than 6 consecutive hours
if the rise is expected to be short term, what can you allow the headwater elevation to rise to
445.15
what is freeboard
distance from the top of the water level to the top of the spillway gate
Flow rates for Crop/Flood
Crop - 54,000 CFS
Flood - 90,000 CFS
Rate of release change limits
Increase - 5000CFS
Decrease - 10,000CFS - try to limit to 5000CFS
What happens when headwater gets to 450’
the 5000CFS limit no longer applies and releases my be increased as needed to prevent any further rise
Priorities for drought regulations
water supply water quality navigation hydropower recreation
river flow times
DAL - 11 -
WOL - 20 - COR - 16 -
CEN - 20 - OLD - 5 -
JPP - 5 - CHE - 9 - BAR
What happens when tailwater rises to 402
check sump pump and unwater pump discharge check valves closed
what happens when tailwater rises to 410
remove taildeck gratings and wedge draft tube gates
what happens when tailwater is apparent to reach 418
all signs and buoys should be removed
all water tight covers placed
power turned off to tail deck circuits
move crane to land side & kill power
remove warning horn system and place water tight covers
draft tube and scroll case access doors bolted closed - units will automatically fill if not closed
prior to headwater elevation 450
close water tight doors between spillway and draft tube access galleries and valve U2
minimum net head
18’
What does the spillway gate sign read and when
Danger Dam - spillway gates closed
Danger Dam Open - spillway gates open
what form do the operators use to record daily CFS
ORN form 84A
where is the rain gauge and temp recorder, what times are they read
switchyard
6AM
6PM
What are the combined flows
OLD - turbine and spillway discharge
Nashville - OLD and JPP discharge
After the combined flow reaches 90,000 CFS, gate operation shall be based on rising headwater level at a rate between what
.1 to .2 ft/hr