Home
All Requests
Map ViewerBrentwood City Of - 5-022.15 SAN JOAQUIN VALLEY - TRACY
Brentwood City Of - 5-022.15 SAN JOAQUIN VALLEY - TRACY
A. Applicant Information
Requesting Agency Information
|
|||
|---|---|---|---|
| Agency Name: | Brentwood City Of | ||
| Address: | 150 City Park Way | ||
| City: | Brentwood | Zip: | 94513-7344 |
| Work Phone: | (925) 516-6000 | Cell Phone: | (925) 382-9410 |
| Email: | cehlers@brentwoodca.gov | Fax: | |
| Revision Request Manager Information
|
|||
|---|---|---|---|
| Person Name: | Eric Brennan | ||
| Address: | 150 City Park Way | ||
| City: | Brentwood | Zip: | 94513 |
| Work Phone: | 925-516-6020 | Cell Phone: | |
| Email: | ebrennan@brentwoodca.gov | Fax: | |
B. Description of Proposed Boundary Modification
-
Subdivide Tracy Subbasin (5-022.15) at the Contra Costa County line.
-
- Jurisdiction Subdivision
-
The proposed modification would separate the subbasin along jurisdictional lines; carving out that portion of the Tracy Subbasin that lies within Contra Costa County. The current subbasin substantially consists of areas of San Joaquin County and east Contra Costa County, with a small portion of Alameda County. The Contra Costa County line along Old River is proposed as the new eastern boundary of the new subbasin. The Contra Costa-Alameda County Line would be the new southern boundary. The new subbasin would be bounded by the Coast Ranges to the west (unchanged), Old River to the east (new), San Joaquin River to the north (unchanged), and Alameda County Line to the south (new). The proposed boundary modifications are consistent in nature with existing Bulletin 118 boundaries: Old River replaces the San Joaquin River (river) and Alameda County Line replaces the Stanislaus County line (political) to form the new subbasin within Contra Costa County. Eastern Contra Costa County has diverse sources of water supplies including surface water and groundwater, which are used for agricultural and municipal/domestic purposes. The proposed subdivision would affect no existing or historic water supply coordination with other local agencies in the subbasin. There are no published studies or agency reports that indicate a hydrogeologic connection between the east Contra Costa County portion of the subbasin and the San Joaquin/Alameda County portions. Recently published East Contra Costa Agency reports indicate no undesirable results affecting sustainable groundwater use in the area. These include a Groundwater Management Plan (Diablo Water District, 2007; Attachment B-3a), a Water Master Plan (Town of Discovery Bay, 2012; Attachment B-3b), a groundwater conditions report (Diablo Water District, 2011; Attachment B-3c), an IRWMP (2014; Attachment B-3d), and an updated groundwater conditions report (2018; Attachment B-3e). These documents are uploaded to support the proposed basin modification request.
-
- 5-022.15 SAN JOAQUIN VALLEY - TRACY
-
East Contra Costa Subbasin; Tracy Subbasin
C. Initial Notification and Combination of Requests
-
Yes
Local Agency Potential Basin(s)/Subbasin(s) San Luis & Delta-Mendota Water Authority 5-022.07 SAN JOAQUIN VALLEY - DELTA-MENDOTA , 5-022.15 SAN JOAQUIN VALLEY - TRACY Brentwood City Of 5-022.15 SAN JOAQUIN VALLEY - TRACY 5-022.15 SAN JOAQUIN VALLEY - TRACY , 5-021.66 SACRAMENTO VALLEY - SOLANO Brentwood City Of 5-022.15 SAN JOAQUIN VALLEY - TRACY Lathrop City Of 5-022.15 SAN JOAQUIN VALLEY - TRACY , 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN -
No
D. Required Documents for All Modifications
Water supply for the City of Brentwood is addressed in the Infrastructure Element of the General Plan. Preliminarily, the City has determined that CEQA compliance for the proposed modification is by way of the General Plan EIR that was certified in 2014.
E. General Information
From Bulletin 118, Update 2016, the current boundaries for the Tracy Subbasin are described as follows: "The Tracy Subbasin is located in the northeastern portion of the San Joaquin Valley groundwater basin near the Sacramento-San Joaquin delta and the San Francisco Bay. The Subbasin lies between the consolidated rocks of the coast range on the west and the San Joaquin River on the east. To the north the subbasin borders the Pittsburg Plain groundwater basin at the boundary between the San Francisco Bay an San Joaquin River watersheds. The southeastern boundary consists of a combination of county and water district boundaries where it borders the Delta-Mendota Subbasin. The subbasin boundary is defined by 11 segments detailed in the descriptions below."
The new subbasin would be bounded by the Diablo Range to the west (unchanged), San Joaquin River to the north (unchanged), Old River to the east corresponding to the San Joaquin and Contra Costa county lines (new), , and Alameda County Line to the south (new). The proposed boundary modifications are consistent in nature with the existing Bulletin 118 boundaries: Old River replaces the San Joaquin River (river) and Alameda County Line replaces the Stanislaus County Line (geopolitical) to form the new subbasin within Contra Costa County.
The base of fresh water (bottom of the basin) is at the contact of two Tertiary units, the upper nonmarine Pliocene deposits and the lower Miocene marine/nonmarine deposits. This contact generally slopes eastward starting about 200 feet above mean sea level in the western portion of the subbasin to about 1,000 feet or greater on the eastern edge of the subbasin (Attachment E-1, Base of Freshwater Map). The Corcoran Clay is a prominent demarcation between the primary upper and lower freshwater aquifer sequences of the San Joaquin Valley. However, the Corcoran Clay is absent in the Contra Costa County portion of the Tracy Subbasin.
F. Notice and Consultation
A full list of 154 public water systems (PWS) and local agencies (94 in East Contra Costa County and 60 in San Joaquin County) are included in Attachments F-1a (East Contra Costa County) and F-1b (San Joaquin/Alameda Counties). Some of these are listed below as well.
Counties: Alameda County Flood Control & Water Conservation District - Zone 7 (agency created by statute to manage groundwater in Alameda County portion of Tracy Subbasin); Contra Costa County; San Joaquin County
Cities: Antioch; Brentwood; Oakley; Tracy
Special Districts: Bethel Island Municipal Improvement District; Banta-Carbona Irrigation District; Byron Bethany Irrigation District; Central Delta Water District; Contra Costa Water District; Diablo Water District; Discovery Bay Community Services District; East Contra Costa Irrigation District; Ironhouse Sanitary District; Mountain House Community Services District; Naglee Burk Irrigation District; Oakwood Lake Water District; South Delta Water Agency; Stockton East Water District; Westside Irrigation District; Reclamation District (RD) 2024 (Orwood and Palm Tracts); RD 2025 (Holland Tract); RD 2026 (Webb Tract); RD 2059 (Bradford Island); RD 2065 (Veale Tract); RD 2090 (Quimby Island); RD 2117 (Coney Island); RD 2121 (Bixler Tract); RD 2137; RD 799 (Hotchkiss Tract); RD 800 (Byron Tract); RD 830 (Jersey Island); Union Island R.D.; Union Island R.D.; Pico and Naglee R.D.; Mandeville Island R.D.;Bacon Island R.D.; McDonald Island R.D.; Lower Jones Tract R.D.; Upper Jones Tract R.D.; Victoria Island R.D.; Medford Island R.D.; Pescadero District R.D.; Stewart Tract R.D.; Woodward Island R.D.; Kasson District R.D.; Stark Tract R.D.; Paradise Junction R.D.; Mossdale R.D.; Tinsley Island R.D.; Fay Island R.D.; Holt Station R.D.; Little Mandeville Island R.D.; Rough and Ready Island R.D.; Middle Roberts Island R.D.; Upper Roberts Island R.D.; Lower Roberts Island R.D.; Fabian Tract R.D..
Groundwater Sustainability Agencies (GSAs): There are twelve (12) exclusive GSAs in the Tracy Subbasin, as seen in the attachment (Attachment F-1c). Banta-Carbona Irrigation District; Byron-Bethany Irrigation District; City of Antioch; City of Brentwood; Contra Costa County; Diablo Water District; Discovery Bay Community Services District; East Contra Costa Irrigation District; San Joaquin County; Stewart Tract GSA; City of Tracy; West Side Irrigation District. Seven of these GSAs are within the East Contra Costa proposed modified groundwater subbasin: City of Brentwood; Contra Costa County; Discovery Bay Community Services District; City of Antioch; Byron-Bethany Irrigation District; East Contra Costa Irrigation District; and Diablo Water District. Byron-Bethany Irrigation District is contained in both portions of the current Tracy Subbasin (the East Contra Costa portion and the San Joaquin/Alameda County portion), but the remainder of the GSAs are contained in the San Joaquin/Alameda County portion of the subbasin. (note: The County of Sacramento is not an ?Exclusive GSA? in the Tracy Subbasin and is requesting a jurisdictional basin boundary modification to move 580 acres from the Tracy Subbasin and into the Solano Subbasin. The new boundary would align with county lines and would optimize management activities. It is assumed that the Sacramento County application will be successful, and it is not included as a GSA for this application.)
The Tracy Subbasin 2016 BBM request was initiated in December 2014, with numerous meetings between local agencies in the San Joaquin County (SJC) and East Contra Costa County (ECCC) portions of the Tracy Subbasin. The meetings were concerned with GSA and GSP alternatives, as well as basin boundary modifications (agendas are uploaded as attachments for documentation, Attachments F-2a to F-2g) and local agencies and public water systems (PWS) were identified. These lists were revised and updated for this second application, the East Contra Costa PWS list and agencies was discussed at many meetings (Attachments F-2h to F-2o). On March 13, 2018 DWR clarified the ¾ support requirement for the jurisdiction subdivision modification; there are two types of support required: local agency and public water systems. The Tracy Subbasin needs ¾ support of all local agencies and 3/4 support from all PWS (Attachment F-2p).
The PWS definition used by both ECCC and SJC was based on the legislative description (Section 116275 of the Health and Safety Code) "...15 or more service connections or regularly serves at least 25 individuals daily at least 60 days out of the year." ECCC PWS list was updated on March 21, 2018 by Timothy L. Ellsworth, with Contra Costa Environmental Health (Attachment F-2l) and two systems were deleted by Timothy Ellsworth on July 24, 2018 (Attachment F-2q).
The Local Agency definition used by both ECCC and SJC was basin on the legislative description (Water Code 10721) "(n) "Local agency" means a local public agency that has water supply, water management, or land use responsibilities within a groundwater basin."
Letters with a map attached (Attachment F-3a from East Contra Costa and Attachment F-3b from SJC) were sent to Public Water Systems and local agencies informing them about the proposed basin boundary modification. Follow up phone calls were made as well. Copies of the returned signed letters and correspondence are attached (Attachment F-3c and F-3d).
In order to comply with Section 343.12, notifications were sent on September 18, 2018 to both ECCC and SJC (Attachments F-3e and F-3f, respectively) local agencies and public water systems. The cards and letters informed the parties that the BBMR had been submitted to DWR. The notification provided guidance on where and how to submit comments and the submission deadline.
Agendas are attached (Attachments F-4a to F-4r) for all meetings where the proposed boundary modification was discussed (2014 to 2018). A table of all meetings is in Attachment F-4s.
Two uploaded files (Attachments F-5a and F-5b) include all the entities contacted to request support for the basin boundary modification. The attachments include the returned support cards and in some cases the repeated contact notes of interaction.
G. General Existing Groundwater Management
All requests for jurisdictional modification pursuant to Section 342.4 MUST include responses to the following questions.
The proposed basin modification would align historical and current planning and management efforts with SGMA. The new subbasin boundaries would be effectively integrated to existing AB3030, IRWMP, CASGEM plan areas. The local agencies that have historically coordinated these and other activities, entered into an MOU for the development of a GSP that covers the proposed new subbasin. This MOU is included as an attachment here (Attachment G-1a). Cooperation among east Contra Costa County agencies has been a factor in development of a hydrogeologic conceptualization and a monitoring program to detect undesirable results if they should arise. Consistent with the Medium Priority ranking of the greater Tracy Subbasin, sustainable groundwater management presently exists within the proposed new subbasin. Examples of existing groundwater management are provided in the attachments, including the Diablo Water District's Groundwater Management Plan (dated 2007) (Attachment G-1b); the Diablo Water District's 2011 Groundwater Monitoring Report (Attachment G-1c); the East Contra Costa County CASGEM Network Plan (updated 2014) (Attachment G-1d); and the East Contra Costa County IRWMP (updated 2013 Attachment G-1e). The map in Attachment G-1f illustrates the land within the Tracy Subbasin that is covered by GWMPs and IRWMPs. Current groundwater conditions are presented in a report completed in May 2018 (Attachment G-1g), which illustrate relatively stable conditions in the subbasin and provide representative groundwater level hydrographs.
Due to hydrogeologic variations across the Tracy Subbasin (see section I), there are no expected constraints on sustainability posed by the modification in the balance of the subbasin. Attachments are provided (Attachments G-2a, G-2b, G-2c) that demonstrate groundwater management within the proposed subbasin subdivision of the East Contra Costa area and that the water bearing zones of the East Contra Costa County are separate from the San Joaquin county portion of the Tracy Subbasin (Attachment G-2a, page 3).
The following explains why the modification does not affect sustainable management in other adjoining subbasins:
North: This boundary is unchanged.
West: This boundary is uncharged and there is no subbasin in the Coast Ranges adjoining the proposed new subbasin.
East: The boundary shift from San Joaquin River to Old River (i.e., to the Contra Costa-San Joaquin county border) is across the Delta islands where groundwater occurrence and availability is restricted.
South: This boundary is shifted north from the Stanislaus County line to Alameda County line. Within this shift is the Tracy area, which is hydrogeologically distinct from east Contra Costa County with little to no groundwater use between the two areas (e.g., Clifton Forebay). No change to the southernmost boundary of the Tracy Subbasin is proposed. The southern portion of the Tracy Subbasin adjoins the Delta-Mendota Subbasin, which is known to be hydraulically connected. There is no history of joint water resource planning or integration that would be affected by the proposed southern boundary shift.
In 1999, members of the East Contra Costa Water Management Association commissioned a study of local groundwater conditions that led to increased awareness of the need to monitor groundwater levels in the region due to lack of systematic programs. The same local agencies cooperated in Diablo Water District's 2007 AB3030 Groundwater Management Plan (Attachment G-3a) preparation that identified the need for groundwater level monitoring and reporting. In 2011, Diablo Water District produced a groundwater monitoring report (Attachment G-3b) to update information compiled in the 2007 GWMP. Wells of major groundwater users are part of the 2014 CASGEM plan (Attachment G-3c) that covers the entire proposed basin modification area. As part of the region's IRWMP Update 2013, the cooperating agencies identified data gaps to address a determination of safe yield for the east Contra Costa area (Attachment G-3d). The 2018 groundwater conditions update shows stable conditions in the proposed East Contra Costa Subbasin (Attachment G-3e).
The proposed boundary modification has no impact on existing state programs as the East Contra Costa area has complied and developed plans (Attachments G-4a and G-4b) that have been independent of the rest of the Tracy Subbasin. The CASGEM coverage is complete within the proposed new subbasin (Attachment G-2c), the East Contra Costa County IRWMP Update 2013 (Attachment G-1e) only covers the East Contra Costa County portion of the Tracy subbasin, and previous AB3030 plan areas are aligned within areas that would not be affected by the proposed modification (Attachment G-1f). Although the Tracy Subbasin Groundwater Sustainability Plan is currently proceeding as one document, the East Contra Costa County and San Joaquin County Groundwater Sustainability Agencies are communicating (with facilitation provided by the DWR Facilitation Support Services Grant) and anticipating the production of two GSP documents (e.g., Tracy Subbasin and East Contra Costa Subbasin) once the basin boundary modification has been approved.
H. Local Support
All requests for boundary modification must include the following:
The attached letter and map (Attachment H-1a for ECC and H-1b for SJC) was submitted to identified affected local agencies and public water systems about the proposed basin boundary modification. Follow up telephone calls were made as well.
Attachments F-5a and F-5b are the lists of agencies and public water systems that were contacted and those that replied/sent return cards or a comment in support of the basin boundary modification. Also included in these attachments are copies of the signed letter of support and some notes about interactions with the entities.
Not applicable.
Attached (Attachment H-4c) is a summary table of the Tracy Subbasin: total public water systems (91) and local agencies (62); required ¾ support for public water systems (68) and local agencies (47); and support cards received for public water systems (70) and local agencies (50). Over three-fourths of Tracy Subbasin public water systems and local agencies provided their support.
A full list of 153 public water systems (PWS) and local agencies are included in Attachments H-4c. Attachements F-5a and F-5b are support cards received organized by county (ECCC and SJC, respectively).
I. Hydrogeologic Conceptual Model
Requests for boundary modification, must include a document or text to a clearly defined hydrogeologic conceptual model demonstrating each of the following:
See attached summary (Attachment I) and supporting documents Attachment I-a, I-b, G-4a, G-1c, I-e, and G-3e.
L. Technical Studies for All Jurisdictional Modifications
Requests for a jurisdictional boundary must attach or provide a URL or upload a file for the following:
The following east Contra Costa County agencies have agreed to work cooperatively to comply with the requirements of SGMA: City of Antioch, Byron Bethany Irrigation District, City of Brentwood, Contra Costa County, Contra Costa Water District, Diablo Water District, East Contra Costa Irrigation District, Town of Discovery Bay Community Services District. These agencies developed an MOU that provided a framework through which they are developing a GSP that covers the east Contra Costa County portion of the Tracy Subbasin (Attachment G-1a). The second attachment shows a map of the exclusive GSAs in the Tracy Subbasin (Attachment F-1c).
M. Technical Studies for Jurisdictional Subdivision Modifications
Requests for jurisdictional subdivisions must include a document that describes the historical and current groundwater conditions and coordination within the existing basin or subbasin related to the following, where applicable:
A description of historical and current groundwater conditions and coordination in the basin can be found in Attachment "M-aa Response Question M.pdf".
