SUPERSEDED. BDCP Conservation Measure 1: Water Facilities and Operation. BDCP Bay Delta Conservation Plan

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Neil Gordon
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BDCP Bay Delta Conservation Plan March 2013 BDCP Conservation Measure 1: Water Facilities and Operation A cornerstone of the Bay Delta Conservation Plan (BDCP) strategy is to construct and operate a

ecosystem and California s water supplies.

1 BDCP Bay Delta Conservation Plan March 2013 BDCP Conservation Measure 1: Water Facilities and Operation A cornerstone of the Bay Delta Conservation Plan (BDCP) strategy is to construct and operate a dual-conveyance water delivery system that would modernize the heart of California s aging water supply network in a way that balances the needs of the Sacramento-San Joaquin iver Delta (Delta) ecosystem and California s water supplies. The new north Delta diversions will be subject to strict operating criteria to generate river and Delta conditions needed for improving fish populations and to protect water quality and water rights of those in the Delta. Conservation Measure 1 (CM1) would make substantial changes to water operations in the Delta by implementing a dual-conveyance system that focuses on two major components: 1. Construction of new water facilities, including: Three new north Delta intakes with state-of the art fish screens Two 35-mile long tunnels New Head of Old iver operable gate 2. Operation of both new and existing water conveyance facilities, including: North Delta intakes South Delta export facilities Delta Cross Channel gates Suisun Marsh Salinity Control Gates North Bay Aqueduct intake The existing operation of the State Water Project (SWP) and Central Valley (CVP) pumps in the southern Delta and habitat can cause or increase a reversal in river flows, alter salmon migratory patterns, and contribute to the decline of sensitive fish species such as the Delta smelt. By relocating the main point of water diversion to the north and establishing new operating criteria to improve water volume, timing, turbidity, and salinity, along with other conservation measures, the BDCP will improve native fish migratory patterns and habitat conditions and allow for greater operational flexibility. Considering the goals of water supply and ecosystem health, the BDCP would implement flow management changes to address the following flow-related issues for fish: everse flows in Old iver and Middle iver Entrainment, salvage, and predation effects on native fish species due to south Delta intakes Delta Cross Channel effects on fish migration Salinity, flow, and habitat in Suisun Marsh Flow modification effects in the Sacramento iver Effects on Delta outflows Effects of climate change SUPESEDED The BDCP will be managed adaptively based on the ability to meet BDCP biological goals and objectives. Operation of the water system will be governed with input from scientists, regulatory agencies, water users, and the public. Facility Size The proposed water diversion facility capacity has been reduced from 15,000 to 9,000 cubic feet per second (cfs), a 40 percent reduction from previous proposals. In addition, the number of river intakes has dropped from five to three, largely in response to the potential impact to Delta communities.

Using Gravity to Move Water The proposed BDCP project includes three new intakes along the Sacramento iver in the north Delta and twin tunnels, approximately 35 miles long, to carry water under the

The twin tunnels would be lined with concrete segments and capable of moving 9,000 cubic feet per second.

Sedimentation Pumping Basin Plant Tunnel and Intake Design and Construction The proposed tunnel and intake facilities will: Protect the state s most critical water delivery system by ensuring that

by using the latest seismic criteria and design methodologies in the tunneling industry The new water delivery system would be built using proven tunnel-boring machine technology.

As the machine advances, a pre-cast concrete, segmented tunnel-lining system is installed behind the cutter head, bolted together, and grouted in place.

Surge Tower On-Bank Intake Pipeline or Single-Bore Tunnel Proposed Tunnel System No final decisions on the proposed conveyance facility have been made.

The elements described here are for the purpose of assisting the public review as a guide to the BDCP and proposed project identified in the Environmental Impact eport/environmental Impact Statement.

2 Using Gravity to Move Water The proposed BDCP project includes three new intakes along the Sacramento iver in the north Delta and twin tunnels, approximately 35 miles long, to carry water under the Delta to the CVP and SWP pumping plants. A forebay would be needed near the intakes to hold water diverted from the river, and gravity flow would be used to move water supplies through the tunnels. The twin tunnels would be lined with concrete segments and capable of moving 9,000 cubic feet per second. The gravity-flow system requires two 40 foot-diameter tunnels to convey the needed flows and overcome friction losses to keep water moving through the system. Sedimentation Pumping Basin Plant Tunnel and Intake Design and Construction The proposed tunnel and intake facilities will: Protect the state s most critical water delivery system by ensuring that the new facilities have 200-year flood protection Protect against sea level rise and flooding due to climate change by building intakes upstream in the north Delta Protect against earthquake damage by using the latest seismic criteria and design methodologies in the tunneling industry The new water delivery system would be built using proven tunnel-boring machine technology. Tunnels would be excavated using a circular cutter head that mines through the soil. As the machine advances, a pre-cast concrete, segmented tunnel-lining system is installed behind the cutter head, bolted together, and grouted in place. This proven technique allows the the machine to mine in soft, saturated ground while maintaining the stability and integrity of the surrounding soil. Surge Tower On-Bank Intake Pipeline or Single-Bore Tunnel Proposed Tunnel System No final decisions on the proposed conveyance facility have been made. Completion of environmental review and public input is now underway. The elements described here are for the purpose of assisting the public review as a guide to the BDCP and proposed project identified in the Environmental Impact eport/environmental Impact Statement. Dual-Bore Tunnels: Two 40-foot insidediameter tunnels will be constructed, side by side, more than 150 feet below ground to deliver water supplies to the existing SWP and CVP pumps. Byron Tract : A new forebay would be constructed next to the existing Clifton Court, near the CVP and SWP facilities, to temporarily store water from the tunnels and create a hydrologic break between the tunnels and the existing system. Intermediate Sacramento iver 2 Intermediate : A new forebay would be constructed to temporarily store water before it enters the tunnel system. PE SE M oving the water delivery system underground to reduce exposure to possible system interruption caused by aging levees and seismic and flood events Building intakes in the north Delta to avoid increased salinity from tidal effects and expected climate change Improving regulatory predictability of water diversions by better protecting threatened and endangered fish The gravity-driven system will eliminate the need for an intermediate pumping plant in the Delta. Using gravity to transport water will save tremendous amounts of energy and reduce greenhouse gas emissions. SU The BDCP proposes to secure and protect California s water supply by: CM 1 Features: Three intakes, together capable of diverting up to 9,000 cfs. State-of-the-art fish screens that would protect passing fish. A forebay for temporarily storing the water diverted from the river. Two tunnels to carry water 35 miles to the existing pumping plants in the south Delta. From there, water would be moved into existing aqueducts that supply much of the state. D ED BDCP Water Delivery Facilities Byron Tract South Delta Pumping Plants Dual-Bore Tunnels To DeltaMendota Canal or California Aqueduct California Aqueduct (SWP) Delta-Mendota Canal (CVP) 3

BDCP Flow Patterns to Meet Biological Goals and Objectives SCEEN The primary purpose of Conservation Measure1 is to construct and operate a facility that improves conditions for covered species and

For more information on BDCP flow criteria, see Chapter 3: Conservation Strategy, Section 3.4. Intakes: Three new intake facilities are proposed along the Sacramento iver.

Yolo Bypass Fishery Enhancement (CM2) New North Bay Aqueduct Intakes D ED Manage flows and seasonal habitat to increase fish abundance, passage, survival rates, and operate a new Fremont Weir gate to

Intakes Proposed Implement additional potential flow improvements in the spring to reduce entrainment and provide better Delta spring flow patterns.

Sacramento iver bypass flows managed to allow migrating juvenile salmon to avoid entering the interior Delta, maintain survival past the north Delta diversions, and improve upstream adult migration

P rovide operational flexibility to maintain water levels for south Delta farmers and to improve water quality conditions (salinity control and dissolved oxygen levels) in the San Joaquin iver.

nnel/ Pipeline Suisun Marsh Salinity Control Gate Sa Establish bypass flows up to 15,000 cfs in December n Jo aq uin E stablish bypass flows up to 17,000 cfs during the January through June fish

Delta pumps and to areas of suitable habitat ive r In all other months, manage real-time south Delta operations to substantially reduce entrainment for all fish species, particularly San Joaquin iver

3 BDCP Flow Patterns to Meet Biological Goals and Objectives SCEEN The primary purpose of Conservation Measure1 is to construct and operate a facility that improves conditions for covered species and natural communities in the Delta while improving water supply reliability. Water operations criteria to benefit fish include the key components listed on these two pages. For more information on BDCP flow criteria, see Chapter 3: Conservation Strategy, Section 3.4. Intakes: Three new intake facilities are proposed along the Sacramento iver. Each intake would be constructed to 3,000 cfs capacity, for a total of 9,000 cfs capacity. Intakes would include state-of-the-art fish screens held to performance standards to protect passing fish. Yolo Bypass Fishery Enhancement (CM2) New North Bay Aqueduct Intakes D ED Manage flows and seasonal habitat to increase fish abundance, passage, survival rates, and operate a new Fremont Weir gate to more frequently inundate the Yolo Bypass when Sacramento iver flows are at their peak. Intakes Proposed Implement additional potential flow improvements in the spring to reduce entrainment and provide better Delta spring flow patterns. educe reverse flows in the Old and Middle ivers by opening and closing the operable gate at the head of Old iver to protect fish from entrainment at the existing SWP/CVP pumps and improve fish survival. 4 me nto cra Establish new intakes with 9,000 cfs diversion capacity, operated according to strict operating criteria M anage diversions in real-time similar to south Delta diversions, with Sacramento iver bypass flows managed to allow migrating juvenile salmon to avoid entering the interior Delta, maintain survival past the north Delta diversions, and improve upstream adult migration in the fall Georgiana Slough Non-Physical Barrier educe the straying of salmon, particularly fall and laterun Chinook salmon, into the south Delta channels. P rovide operational flexibility to maintain water levels for south Delta farmers and to improve water quality conditions (salinity control and dissolved oxygen levels) in the San Joaquin iver. T est the use of a gate at Head of Old iver to protect out-migrating fish in the spring. estore floodplain habitat to enhance San Joaquin fish survival rates in wet years. nnel/ Pipeline Suisun Marsh Salinity Control Gate Sa Establish bypass flows up to 15,000 cfs in December n Jo aq uin E stablish bypass flows up to 17,000 cfs during the January through June fish migration period Provide flows to help fish migrate i v er I mplement up to seven barriers, including a nonphysical barrier at Georgiana Slough to guide fish with light and bubbles away from south Delta pumps and to areas of suitable habitat ive r In all other months, manage real-time south Delta operations to substantially reduce entrainment for all fish species, particularly San Joaquin iver fish populations. P rovide flows that support the movement of adult native fish species to spawning habitats educe or avoid impingement, and salvage losses of fish species Middle South Delta Maintain or increase the diversity of spawning, rearing, and migration conditions for native fish species Minimize movement of fish species into areas of high predation Delta Cross Channel Gates Sa For longfin smelt: Lower summer outflow to more closely mimic natural water patterns Manage spring outflows Water Conveyance Tu Increase Delta smelt rearing habitat Increase longfin smelt abundance For Delta smelt: Increase Delta fall outflow from September to November in wet and above normal years Improve low salinity zone rearing habitat in fall SU Because of the potential importance of fall and spring outflows in meeting the biological goals and objectives for Delta and longfin smelt, these two factors are managed by two separate decision trees. The BDCP decision trees for fall and spring outflow are described in more detail on the next page. PE SE Delta Outflow North Delta Delta Cross Channel Gates ver d i Ol Head of Old iver Operable Barrier Manage the Delta Cross Channel gates to improve fish migration. The gates will be closed from December through June and open from July through September. The gates will be managed under real-time operations in October and November based on monitoring for the presence or absence of fish, water quality criteria, and perceived risk. estore more normal northwest flows at Old and Middle iver, particularly in the spring and in wet years, to contribute to Delta outflows. 5

Decision Tree BDCP Operational Criteria Two key areas of uncertainty for the BDCP are: The importance of fall outflow in achieving abundance and habitat

Because of the scientific disagreement over the importance of these two factors in the Plan s ability to meet the biological goals and objectives for

decision-tree process that will be used to evaluate and refine spring and fall outflow criteria prior to initiating CM1 operations.

Clearly articulate scientific hypotheses to test the sufficiency of each operating criteria to meet the biological goals and objectives.

Scenarios (or Initial Operations) 2. Develop and implement a science plan and data collection program to test the hypotheses and reduce uncertainties. 3.

strategy, including spring and fall outflow operating criteria for dual conveyance operations.

to the following criteria: Old iver and Middle iver flows Head of Old iver gate operations Delta outflow North Delta bypass flows To benefit fish, flow

82-year hydrologic data record, or 32 percent of years Above-normal water year: 12 years of 82, or 15 percent Below-normal water year: 14 years of 82,

4 Decision Tree BDCP Operational Criteria Two key areas of uncertainty for the BDCP are: The importance of fall outflow in achieving abundance and habitat objectives for Delta smelt. The importance of spring outflow for achieving the longfin smelt abundance objective. Because of the scientific disagreement over the importance of these two factors in the Plan s ability to meet the biological goals and objectives for these species and their effect on water operations, and the level of uncertainty surrounding them, these two factors are addressed in a collaborative decision-tree process that will be used to evaluate and refine spring and fall outflow criteria prior to initiating CM1 operations. The decision tree process will involve the following steps: 1. Clearly articulate scientific hypotheses to test the sufficiency of each operating criteria to meet the biological goals and objectives BDCP Biological Goals and Objectives Habitat Improvement, Other Stressors Measures, and Flow Management 2016 through 2049 FISH POPULATIONS Outflow Scenarios (or Initial Operations) 2. Develop and implement a science plan and data collection program to test the hypotheses and reduce uncertainties. 3. At the time dual-conveyance operations begin, the permitting agencies identify spring and fall outflow criteria sufficient to meet the biological goals and objectives. The decision-tree process would begin immediately after the plan is approved and functions as an early part of the adaptive management and monitoring program. Once the fall and spring outflow criteria are determined based on the results of the hypotheses-testing process described above, the decision-tree process will end. At that point the adaptive management and monitoring program will continue as the primary process for adjusting all aspects of the conservation strategy, including spring and fall outflow operating criteria for dual conveyance operations. Ecosystem and Species esponse Ecosystem and Fish Population ecovery 2050 Operation of the new and existing water conveyance facilities will be managed to the following criteria: Old iver and Middle iver flows Head of Old iver gate operations Delta outflow North Delta bypass flows To benefit fish, flow criteria will be applied seasonally (month by month) and according to the following five water-year types: Wet water year: the wettest 26 years of the 82-year hydrologic data record, or 32 percent of years Above-normal water year: 12 years of 82, or 15 percent Below-normal water year: 14 years of 82, or 17 percent Dry water year: 18 years of 82, or 22 percent Critical water year: 12 years of 82, or 15 percent SUPESEDED P Permit Term Conclusion Dry Year Example: 6,400 cfs (Jan. 21, 2009) BDCP Maximum Diversion: 384 cfs 5,000 No Diversion (Maximum possible diversion of 9,000 cfs is reached at river flows of 30,571 cfs under proposed operations) 9, , ,000 Applying BDCP Water Diversion Operations Criteria The most sensitive time of year for Delta fisheries is December through June. As an example, the graphic below illustrates operations December through April. Operations would vary depending on the hydrologic conditions (e.g., water year type, actual Sacramento iver flows, fish presence), but would always include a minimum Sacramento iver flow before water could be diverted. Under all conditions, operational criteria require gradual ramping up of diversions and does not interfere with major river flows. 20,000 Wet Year Example: 64,000 cfs (Jan. 21, 2006) BDCP Maximum Diversion: 9,000 cfs Sacramento iver Flow (cfs) 1,600 7,000 35,000 Diverted water up to 9,000 64,000 up to 9,

For more information, or to submit comments, visit www.baydeltaconservationplan.

5 For more information, or to submit comments, visit call , or SUPESEDED

BDCP Public Meeting. November 29, 2012

BDCP Public Meeting. November 29, 2012 BDCP Public Meeting November 29, 2012 BDCP Proposed Project Update and Response to Agency Comments ICF International California Department of Water Resources California Department of Fish and Game U.S.