Darian
01-30-2014, 06:42 PM
Attended the BDCP info meeting today in Sacto. Picked up a lot of good info and had some questions answered by the staff there. I didn't try to cover every subject area, preferring to ask questions about the high level design of the conveyance facilities, potential impact on POD in the Delta, and some questions about funding and liability for payment in the event of default on repayment of the bonded debt on the part of contractors. Aside from the funding questions, I came to the conclusion that almost everything else was modeled by computer to reach assumptions/conclusions.
Simple one; the tunnels were designed to be 40' in diameter for two reasons. First, is the need to have some air (venting) in the tunnels with the water to accommodate flow by gravity (same as the plumbing in our house). Second, that is the diameter of the drilling device.
Actual capacity of the entire dual conveyance system is 15,000 CFS (nothing new there). The capacity of the tunnels is 9,000 CFS due to the need to provide venting.
Water diverted at the intakes on the Sacto River will be transported to an interim forebay and then to the Clifton Court Forebay. Clifton Court forebay will be expanded/divided into two storage areas, one for the water from the tunnels and the other for water diverted from the south Delta. The pumps will be used to pump from one or the other water sources so that Sacramento River and south Delta water will not be mixed in the forebays.
The existing SWP diversion facilities will continue in use. Apparently, DWR anticipates using diversion at the intakes in the Sacramento River at appropriate times and shutting them down to divert directly from the south Delta when appropriate there. This is a timing issue taking into account passage of fish and in-stream flows at each point of diversion.
Since the intakes operate by gravity feed(? see ps), I asked if operation of the pumps at Clifton Court could increase the amount of water diverted from the Sacramento River, inadvertently?? The answer was that the flows between the intakes and the interim forebay could not be affected but the flows from there to Clifton Court could be.
Apparently, project staff are aware of the potential impacts of this project on POD. The subject is very complex and it's difficult to single out a particular stressor as the cause. One solution in BDCP that staff are thinking about is to recover and redeposit sediment removed from the settling basins in the intake complexes onto points in the Delta where tidal action and/or water currents will pull it back into the water. The thinking being that turbidity is necessary for a healthy Delta. Of course, this just addresses the part of the problem with POD that DWR can control.
Asked if the screens at the intakes would be small enough to screen out small organisms, such as fish eggs and larva of broadcast spawners (e.g. Striped Bass/Shad, etc.)? The answer is the screens will not be small enough to prevent entrainment of these size/type organisms.
Spoke to staff about what is the post construction liability of the water contractors in the event they default on the duty to repay the bonds and what is DWR plan to recover that amount should a default occur?? For about a minute, all I got was silence and then, "I don't know." The staffer said DWR doesn't anticipate a default as, by law, public water agencies have the ability to raise rates for their customers. Also, they have the authority to tap into property tax assessments (something I was unaware of).
Still a lot of this stuff to wade thru and I'm trying to keep up. One caution for those planning on attending one of these sessions. Write down your questions in advance and make them as reasonable as possible. Try to make them about aspects of the project not whether you approve of it or not. No anger, please. I spent a lot of time waiting to speak to a staff member while a person argued over and over about a subject area she obviously wasn't informed about. Wasted a lot of time and never got an answer she liked.
DWR staff were very helpful and forthcoming. I believe they answered my questions to the best of their knowledge. I've got a lot more material to read thru, now. :cool:
ps. The BDCP Executive Summary reflects installation of pumping stations at each intake. This would imply that water is taken from the river by pumping to the interim forebay and fed by gravity to Clifton Court.
Simple one; the tunnels were designed to be 40' in diameter for two reasons. First, is the need to have some air (venting) in the tunnels with the water to accommodate flow by gravity (same as the plumbing in our house). Second, that is the diameter of the drilling device.
Actual capacity of the entire dual conveyance system is 15,000 CFS (nothing new there). The capacity of the tunnels is 9,000 CFS due to the need to provide venting.
Water diverted at the intakes on the Sacto River will be transported to an interim forebay and then to the Clifton Court Forebay. Clifton Court forebay will be expanded/divided into two storage areas, one for the water from the tunnels and the other for water diverted from the south Delta. The pumps will be used to pump from one or the other water sources so that Sacramento River and south Delta water will not be mixed in the forebays.
The existing SWP diversion facilities will continue in use. Apparently, DWR anticipates using diversion at the intakes in the Sacramento River at appropriate times and shutting them down to divert directly from the south Delta when appropriate there. This is a timing issue taking into account passage of fish and in-stream flows at each point of diversion.
Since the intakes operate by gravity feed(? see ps), I asked if operation of the pumps at Clifton Court could increase the amount of water diverted from the Sacramento River, inadvertently?? The answer was that the flows between the intakes and the interim forebay could not be affected but the flows from there to Clifton Court could be.
Apparently, project staff are aware of the potential impacts of this project on POD. The subject is very complex and it's difficult to single out a particular stressor as the cause. One solution in BDCP that staff are thinking about is to recover and redeposit sediment removed from the settling basins in the intake complexes onto points in the Delta where tidal action and/or water currents will pull it back into the water. The thinking being that turbidity is necessary for a healthy Delta. Of course, this just addresses the part of the problem with POD that DWR can control.
Asked if the screens at the intakes would be small enough to screen out small organisms, such as fish eggs and larva of broadcast spawners (e.g. Striped Bass/Shad, etc.)? The answer is the screens will not be small enough to prevent entrainment of these size/type organisms.
Spoke to staff about what is the post construction liability of the water contractors in the event they default on the duty to repay the bonds and what is DWR plan to recover that amount should a default occur?? For about a minute, all I got was silence and then, "I don't know." The staffer said DWR doesn't anticipate a default as, by law, public water agencies have the ability to raise rates for their customers. Also, they have the authority to tap into property tax assessments (something I was unaware of).
Still a lot of this stuff to wade thru and I'm trying to keep up. One caution for those planning on attending one of these sessions. Write down your questions in advance and make them as reasonable as possible. Try to make them about aspects of the project not whether you approve of it or not. No anger, please. I spent a lot of time waiting to speak to a staff member while a person argued over and over about a subject area she obviously wasn't informed about. Wasted a lot of time and never got an answer she liked.
DWR staff were very helpful and forthcoming. I believe they answered my questions to the best of their knowledge. I've got a lot more material to read thru, now. :cool:
ps. The BDCP Executive Summary reflects installation of pumping stations at each intake. This would imply that water is taken from the river by pumping to the interim forebay and fed by gravity to Clifton Court.