B. Description of Proposed Boundary Modification

1. Short Description

   Internal Jurisdictional Modification to Incorporate RD 150, RD 307, & RD 999 into the Yolo Subbasin
2. Type of basin boundary revision

   • Jurisdiction Internal
3. Provide a narrative overview of the boundary modification request and how the resulting modification would affect likelihood of sustainable management.

   The boundary modification request is meant to move the internal boundary line between Yolo and Solano Subbasin to bring Yolo County-reclamation districts into the Yolo Subbasin. At this time, RD 150 and RD 999 are requesting incorporation into the Yolo Subbasin, and RD 307 plans to join the proposed North Delta Subbasin. Should the proposed North Delta Subbasin not be approved by DWR, the YSGA is interested in incorporating RD 307 into the Yolo Subbasin so as to not create any islands.

   Attachment(s):
4. List the existing basin(s)/subbasin(s) to be modified by this request

   • 5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN
   • 5-021.66 SACRAMENTO VALLEY - SOLANO
   • 5-021.67 SACRAMENTO VALLEY - YOLO
5. Provide the proposed name for the new basin(s) or subbasin(s)

C. Initial Notification and Combination of Requests

1. Was an initial notification submitted to the Department?

   Yes
   List of submitted initial notification for the selected basin(s)/subbasin(s).

   Local Agency	Potential Basin(s)/Subbasin(s)
   Sloughhouse Resource Conservation District	5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN , 5-022.16 SAN JOAQUIN VALLEY - COSUMNES
   Omochumne-Hartnell Water District	5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN , 5-022.16 SAN JOAQUIN VALLEY - COSUMNES
   Northern Delta GSA	5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN , 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN , 5-021.66 SACRAMENTO VALLEY - SOLANO
   Omochumne-Hartnell Water District	5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN , 5-022.16 SAN JOAQUIN VALLEY - COSUMNES
   	5-021.66 SACRAMENTO VALLEY - SOLANO , 5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN , 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN
   Yolo County Flood Control And Water Conservation District	5-021.52 SACRAMENTO VALLEY - COLUSA , 5-021.67 SACRAMENTO VALLEY - YOLO , 5-021.66 SACRAMENTO VALLEY - SOLANO
   	5-021.67 SACRAMENTO VALLEY - YOLO , 5-021.66 SACRAMENTO VALLEY - SOLANO
   	5-022.15 SAN JOAQUIN VALLEY - TRACY , 5-021.66 SACRAMENTO VALLEY - SOLANO

2. Does this application include a combination of requests?

   No

D. Required Documents for All Modifications

1. A copy of the statutory or other legal authority under which the requesting agency was created with specific citations to the provisions setting forth the duties and responsibilities of the agency.

Attachment(s):

• Yolo Subbasin_JPA_Agreement_Final.pdf (1.6MB) Uploaded on 08/20/2018 at 12:27PM

2. A copy of the signed resolution adopted by the requesting agency formally initiating the boundary modification request process.

Attachment(s):

• RESOLUTION 2018-2_YSGA Authorizes BBM Request (signed).pdf (53kB) Uploaded on 08/20/2018 at 12:27PM

3. A map of adequate scale (no greater than 1:24,000; e.g., 1:10,000 is not acceptable) showing the proposed modified basin boundary in relation to the existing Bulletin-118 basin boundary and the local agencies that are within or bordering the existing and proposed basin.

Attachment(s):

• Proposed Yolo and Solano Subbasin and Existing B118 Boundaries_wRD307.pdf (754.4kB) Uploaded on 09/17/2018 at 10:08AM
• Proposed Yolo and Solano Subbasin and Existing B118 Boundaries_woRD307.pdf (764.4kB) Uploaded on 09/17/2018 at 10:07AM

4. A GIS shapefile of the proposed modified groundwater basin boundaries. Download Existing B118 basin shape file | DWR Spatial Data Standards

Attachment(s):

• YoloBBMRS_Revised Basins_w_RD307.zip (211.5kB) Uploaded on 11/20/2018 at 09:45AM

5. A GIS shapefile of the political boundaries of any affected or adjacent local agency. Download water agency shape file

Attachment(s):

• BBM2018_AffectedGSAs.zip (60.2kB) Uploaded on 09/13/2018 at 10:50AM

6. Any information, if necessary, to enable DWR to satisfy the requirements of a responsible agency pursuant to the California Environmental Quality Act.

This basin boundary modification request is exempt from CEQA.

E. General Information

1. Describe the lateral boundaries of the alluvial aquifer or aquifers that form the groundwater basin and the definable bottom of the basin. The description must be in terms that are clear, definite, and sufficiently detailed to allow an authoritative map of the proposed basin boundaries to be plotted using the given description.

Bounded on the east by the Sacramento River and and the eastern boundary of Reclamation District (RD) 150 and the eastern boundary of RD 307, and bounded on the south by the Yolo County/Solano County line and the northern boundary of RD 2068 and southern boundary of RD 999. Bounded on the north by the Colusa County/Yolo County line, and bounded on the west by the Capay Valley and the Coast Range. The geologic structure of the groundwater subbasin is dominated by an anticlinal ridge oriented northwest to southeast, which is expressed at the surface as the Dunnigan Hills and Plainfield Ridge. The definable bottom has yet to be defined for the entire Yolo Subbasin, since it was recently revised there has not been an updated hydrogeological conceptual model. Please see the Bulletin-118 (2003) description for more information: https://water.ca.gov/LegacyFiles/pubs/groundwater/bulletin_118/basindescriptions/5-21.67.pdf

F. Notice and Consultation

1. List all local agencies and public water systems affected by the basin(s) modification request.

Local Agencies directly affected: Yolo Subbasin Groundwater Agency, Reclamation Districts (RDs) 150, 307, and 999, and Solano Subbasin Groundwater Sustainability Agency. Local agencies indirectly affected: Solano County, Sacramento County, Sacramento Central Groundwater Authority, Franklin Drainage District, and RDs 349, 501, 551,744, 755, 813, 1667.

2. Explain the methods used to identify interested local agencies and public water systems in the affected basin(s):

During the development of the YSGA, staff did their due diligence to track local agencies and water agencies within the County and has maintained a stakeholder coordination list since that effort. There has been coordination with the Solano Subbasin via the Solano County GSA and County of Solano and American Subbasin via the Sacramento Central Groundwater Authority and Sacramento County. There have been numerous discussions with The Freshwater Trust about the potential North Delta Subbasin.

3. Provide information regarding the nature of consultations with affected or interested agencies. Attach and cite any copies of correspondences with local agencies and public water systems and/or any other persons or entities consulted.

The YSGA has been in constant communication with RD 307 and worked diligently over the past year to inform them of their option to join the Yolo Subbasin. The YSGA has also maintained communications with Solano Subbasin GSA and Solano County and provided the attached formal letters of intent regarding the modification and fate of RD 307. RD 999 and RD 150 have been made aware of the YSGA's timeline and intention, and both agencies authorized joining the Yolo Subbasin in October 2017 (as provided in the notice of intent to DWR). Numerous emails and phone calls took place during the consultation period. Additionally, since the BBM request considers a second option or "backup plan", the YSGA has consulted with Sacramento County and Sacramento Central Groundwater Authority regarding the impact to South American Subbasin if the proposed North Delta Subbasin does not work out. Currently, the Yolo Subbasin would become the South American Subbasin's neighbor to the west of the County line.

Attachment(s):

• Yolo Subbasin BBMRS_Letter to Sacramento County_20180911.pdf (349.8kB) Uploaded on 09/12/2018 at 10:28AM
• Yolo Subbasin BBMRS_Letter to SCGA_20180912.pdf (352.4kB) Uploaded on 09/14/2018 at 08:54AM
• Letter to Solano County_20180918.pdf (355.7kB) Uploaded on 09/18/2018 at 11:33AM
• Letter to Solano Subbasin GSA_20180817.pdf (347.1kB) Uploaded on 08/20/2018 at 12:36PM

4. Provide a summary of all public meetings at which the proposed boundary modification was discussed or considered by the requesting agency. Attach and cite any copies of agendas and notices published.

Coordination activities for the Basin Boundary Modification and the YSGA's intention in requesting a modification were reported during 2018 YSGA Board Meetings within the Executive Officer's Report. At the June 18, 2018 YSGA Board meeting, the Directors formally considered the proposed modification and passed the attached resolution authorizing the basin boundary modification. YSGA staff will also be providing an update on the BBM efforts at the YSGA's September 17, 2018 Board meeting.

Attachment(s):

• BOD_YSGA_Agenda_03-19-18.pdf (1MB) Uploaded on 09/13/2018 at 11:01AM
• BOD_AgendaPacket_06-18-18(web).pdf (1.9MB) Uploaded on 08/22/2018 at 10:47AM
• RESOLUTION 2018-2_YSGA Authorizes BBM Request (signed).pdf (53kB) Uploaded on 08/22/2018 at 10:48AM

5. Attach a copy of all comments regarding the proposed boundary modification received by the requesting agency and a summary of any responses made by the requesting agency.

There were no comments received by the YSGA regarding the proposed basin boundary modification.

G. General Existing Groundwater Management

1. Explain how sustainable groundwater management exists or could likely be achieved in the basin:

Currently sustainable groundwater management has existed for the past 25 years through the Water Resources Association of Yolo County, which consists of local water agencies in Yolo County who have proactively monitored groundwater and conjunctively managed the County's water supplies. The Water Resources Information Database (WRID) consists of 110 groundwater wells that monitor groundwater levels within the Subbasin on a biannual basis. There have been dozens of groundwater management reports written over the past 30 years and the empirical data and supporting documentation will all be helpful in developing the Yolo Subbasin GSP. The Cities of Woodland and Davis have recently acquired surface water rights, taking pressure off of the County's groundwater reliance, and water managers are continually examining new ways to bring surface water supplies into the County to optimize conjunctive use.

2. Explain how the proposed boundary modification would affect the ability of adjacent groundwater basins to sustainably manage groundwater in those groundwater basins.

The Yolo Subbasin Groundwater Agency (YSGA) plans to continue relationships with neighboring subbasins and will formalize relationships and responsibilities with individual coordination agreements. The YSGA plans to share all data and resources with neighboring subbasins to best understand the underground flow patterns across boundaries. By reducing the number of GSAs within Yolo County, the YSGA is streamlining SGMA implementation and providing for centralized management between larger agencies.

3. Provide a historical summary of the sustainable management of groundwater levels in the proposed basin(s) or subbasin(s).

Historical groundwater level data can be found for individual wells on the Yolo Groundwater website: http://yologroundwater.org/index.php/313-2/ Also, historical groundwater level data for all wells that are monitored on a biannual basis can be found on the Yolo Groundwater website: http://yologroundwater.org/index.php/2018/04/20/spring-2018-groundwater-levels-in-the-ycfcwcd-service-area/

4. Discuss potential impacts to state programs resulting from the proposed boundary modification, including, but not limited to, the California Statewide Groundwater Elevation Monitoring (CASGEM), Groundwater Management Plans developed pursuant to AB 3030, Groundwater Sustainability Plans developed pursuant to the Sustainable Groundwater Management Act, any applicable state or regional board plans, and other water management and land use programs.

Since the YSGA is streamlining SGMA implementation and providing for centralized management between larger agencies by reducing the GSAs within Yolo County, there will be great benefit to CASGEM and the development of the Yolo Subbasin GSP. The YSGA is the ME for CASGEM for the entire County and already covers RD 150, RD 307, and RD 999's service areas. Improved management will be the result of the consolidation.

H. Local Support

1. Provide any evidence that sufficient information was provided to affected agencies and systems regarding the proposed boundary modification.

As discussed in Section F - Notice and Consultations, letters were provided to local agencies that would be directly and indirectly affected by the subbasin boundary modification. Additionally, there were numerous phone conversations and meetings with RD 307 and The Freshwater Trust regarding the fate of RD 307.

2. Provide a list of all affected agencies and affected systems that submitted comments and/or documents in support or opposition to the proposed boundary. The agency submitting their support or opposition for a boundary modification must provide a copy of a resolution formally adopted by the decision-making body of the affected agency or system or a letter signed by an executive officer or other official with appropriate delegated authority who represents the agency or system. Attach copies of the resolution and/or signed letter detailing the support or opposition submitted.

To-date, there have been no letters of support or opposition to the proposed subbasin boundary modification. We understand that letters may come in during the public comment period. RD 150 and RD 999 provided resolutions in October 2017 authorizing joining of the Yolo Subbasin, and the YSGA has supported the basin boundary modification.

Attachment(s):

• RESOLUTION-17-08_RD150.pdf (286.3kB) Uploaded on 09/12/2018 at 10:41AM
• RESOLUTION-10-12-01_RD999.PDF (111.2kB) Uploaded on 09/12/2018 at 10:41AM

3. Provide any evidence that rebuts any opposition to the proposed boundary modification.

There has been open communication for more than a year with RD 307 and the The Fresh Water Trust regarding the fate of RD 307's jurisdiction and coverage within a subbasin. It would have been optimal if RD 307 would have incorporated into the Yolo Subbasin for all local planning processes; however, the YSGA respects RD 307's decisions and will support future collaboration with whatever subbasin is neighboring the Yolo Subbasin

I. Hydrogeologic Conceptual Model

1. Principal aquifer units within requested basin.
2. Lateral boundaries of the proposed basin, including:
   1. Geologic features that significantly impede or impact groundwater flow.
   2. Aquifer characteristics that significantly impede or impact groundwater flow.
   3. Significant geologic and hydrologic features and conditions of the principle aquifer units, as appropriate, including information regarding the confined or unconfined nature of the aquifer, facies changes, truncation of units, the presence of faults or folds that impede groundwater flow, or other groundwater flow restricting features.
   4. Key surface water bodies, groundwater divides and significant recharge sources.
3. Recharge and discharge areas within the basin.
4. Definable bottom of the basin or subbasin.

The department may waive this requirement for an internal boundary modification if the requesting agency is able to demonstrate that the proposed boundary modification is unlikely to affect sustainable groundwater management.

The Bulletin 118 Yolo Subbasin 2003 Update is a helpful document for partially defining the HCM for what used to be the Yolo Subbasin: https://water.ca.gov/LegacyFiles/groundwater/bulletin118/basindescriptions/5-21.67.pdf The YSGA is currently in the process of developing a new HCM for capturing and defining the entirety of the Yolo Subbasin. Additionally, this would be considered an internal boundary modification since sustainable groundwater management will be achieved with the YSGA managing the Yolo Subbasin. YSGA plans to continue relationships with neighboring subbasins and will formalize relationships and responsibilities with individual coordination agreements. YSGA also plans to share all data and resources with neighboring subbasins to best understand the underground flow patterns across boundaries. By reducing the number of GSAs within Yolo County, the YSGA is streamlining SGMA implementation and providing for centralized management between larger agencies.

L. Technical Studies for All Jurisdictional Modifications

1. A water management plan that covers or is in the immediate vicinity of the proposed basin or portion of the proposed basin and satisfies the requirement of Water Code sections 10753.7(a) or 10727 by attaching one of the following:
   1. An adopted groundwater management plan, a basin wide management plan, or other integrated regional water management program or plan.
   2. Management pursuant to an adjudication action.
   3. One or more technical studies that cover the relevant portion of a basin or subbasin and adjacent areas.

Attachment(s):

• Technical Studies Documentation.docx (13.9kB) Uploaded on 09/12/2018 at 10:56AM

2. A statement of the existing and planned coordination of sustainable groundwater management activities and responsibilities where required.

The YSGA has been, and is currently, coordinating with the Colusa Subbasin Groundwater Authority and the Solano Subbasin GSA. The YSGA plans to coordinate in the future with the appropriate eastern neighboring subbasin. Appropriate coordination agreements or mutual MOAs will be drafted to outline the data and information sharing and responsibilities of each agency.