DELTA STEWARDSHIP COUNCIL: Examining the science supporting the proposed Delta conveyance amendment
At the May meeting of the Delta Stewardship Council, councilmembers once again took up the issue of the Delta Plan amendment regarding conveyance, storage, and operations.
The draft Delta Plan conveyance, storage, and operations amendment includes recommendations for Delta water management system operations and supporting infrastructure improvements that are intended together and in combination with existing Delta Plan policies and recommendations, to further the coequal goals.
There are three things that move things around in the system: tides, rivers, and exports.
“Almost every one of these other channels is conveying river water or exports or whatever so it’s a pass through system, it’s a conveyance system essentially,” he said.
So for example, we could restore tidal wetlands in Suisun Marsh and improve survival in the north Delta without a single salmon going into Suisun Marsh.” “So to conclude, it’s not just rivers and exports that are moving things around the system, it’s not just rivers and exports that are affecting organisms in the Delta, it’s these three things here that work together that we can work with to actually help achieve the coequal goals.”
“We need to know what ecosystem restoration looks like in order to know what kind of conveyance is acceptable and desirable and what kind of additional storage is acceptable and desirable.” Regarding ecosystem function, the best available science reveals that the key to any restoration of ecosystem function in the Delta will require an improvement in timing and the volume of water flowing into, through, and out of the Delta, Dr. Rosenfield said.
“There are plenty of uncertainties out there that are valid things to consider, but the draft plan that I’m reading seems to be promoting, we need new conveyance of a certain type to achieve our goals when I haven’t seen what the goals actually mean in order to evaluate what kind of conveyance you’ll need or what kind of storage you’ll need.” “In closing, describing the new conveyance and storage plans in the context of how they serve the dual goals is really critical, because simply put, the need for alternative conveyance, storage, and operation depends entirely on how much water will be withdrawn from the Delta in the future,” Dr. Rosenfield concluded.
There’s no scientific debate about that.” “The mechanism – there’s a lot of discussion,” Dr. Rosenfield continued.
So I’m not trying to duck your question … “ “What I’m wondering is whether there are any circumstances where I change in point of diversion or an isolated facility in combination with any other set of solutions that you’ve worked on with BDCP and elsewhere would make sense?,” asked Councilmember Johnston.
“The Bay Institute and myself as professional are willing to look into all potential solutions to improve the status quo, including a different point of diversion, different storage south of Delta, different conveyance, and different operations,” said Dr. Rosenfield.