Northern Delta Groundwater Sustainability Agency - 5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN, 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN, 5-021.66 SACRAMENTO VALLEY - SOLANO

Northern Delta Groundwater Sustainability Agency - 5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN, 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN, 5-021.66 SACRAMENTO VALLEY - SOLANO

A. Applicant Information

Requesting Agency Information
Agency Name: Northern Delta Groundwater Sustainability Agency
Address: 1717 I Street, Suite A
City: Sacramento Zip: 95811
Work Phone: (916) 668-7342 Cell Phone:
Email: northerndeltagsa@gmail.com Fax:
Revision Request Manager Information
Person Name: Erik Ringelberg
Address: 1717 I street
City: Sacramento Zip: 95811
Work Phone: (916) 668-7345 Cell Phone:
Email: northerndeltagsa@gmail.com Fax:
 

B. Description of Proposed Boundary Modification

  1. Jurisdiction subdivision to create a new groundwater subbasin in the northern portion of the Sacramento-San Joaquin River Delta as part of the Sacramento Valley Groundwater Basin.
    • Jurisdiction Subdivision
  2. This boundary modification request seeks to subdivide the South American Subbasin (5-021.65), the Solano Subbasin (5-021.66), and the Eastern San Joaquin Subbasin (5-022.01) in order to create a new groundwater subbasin in the northern reaches of the Sacramento-San Joaquin River Delta where those three existing subbasins intersect. The proposed Northern Delta Subbasin would largely follow the jurisdiction of the Northern Delta Groundwater Sustainability Agency (GSA) and would be part of the Sacramento Valley Basin. The eastern boundary of the Solano Subbasin would shift to the west where it would generally follow Sutter Slough, Miner Slough, Cache Slough, and Sevenmile Slough, removing many of the Delta islands from the existing Subbasin. The southwestern boundary of the South American Subbasin would be shifted further to the east in order to align with the management boundary of the Sacramento Central Groundwater Authority, removing the Stone Lakes National Wildlife Refuge and the areas to the west and south of the Refuge from the South American Subbasin. The northwestern boundary of the Eastern San Joaquin Subbasin would be adjusted to follow the South Mokelumne River, thereby removing Staten Island from the Subbasin. These areas would then form a new groundwater subbasin comprised of the majority of the northern reaches of the Delta. Creating this new Subbasin will facilitate improvements to the sustainable groundwater management in all of the surrounding subbasins by enabling the existing GSAs to better focus their managerial efforts on discrete regions that are homogenous in terms of landscape use, characteristics, and political subdivisions. Currently, the subbasin boundaries, especially those in the South American and Solano Subbasins, do not closely align with the overlying political boundaries, creating administrative complexities. This has created a great deal of discussion about potentially creating ?management areas? under the anticipated groundwater sustainability plans in order to adopt separate and distinct management strategies for different portions of the Subbasins. Creating a new Northern Delta Subbasin in this region will help to remedy these issues and enable the existing GSAs to better focus their efforts on regions that are more homogenous, and therefore simpler to manage under a single groundwater sustainability plan.
    • 5-021.65 SACRAMENTO VALLEY - SOUTH AMERICAN
    • 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN
    • 5-021.66 SACRAMENTO VALLEY - SOLANO
  3. Northern Delta Subbasin

C. Initial Notification and Combination of Requests

  1. Yes
    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
    Eastern San Joaquin County Groundwater Basin Authority 5-022.16 SAN JOAQUIN VALLEY - COSUMNES , 5-022.01 SAN JOAQUIN VALLEY - EASTERN SAN JOAQUIN
    Lathrop City Of 5-022.15 SAN JOAQUIN VALLEY - TRACY , 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. No

D. Required Documents for All Modifications

The proposed basin boundary modification is exempt from CEQA. The attached Notices of Exemption have been filed with the appropriate agencies.

E. General Information

Bounded on the west by the Sacramento River, Babel Slough, Miner Slough, Sutter Slough, Elk Slough, and Winchester Lake, the proposed Northern Delta Subbasin follows the boundaries of Reclamation District 307 along the Sacramento River to the north. The eastern boundary of the proposed Subbasin is comprised of the western border of the Sacramento Central Groundwater Authority, the eastern boundary of Reclamation District 1002, Lost Slough, and the mainstem of the Mokelumne River as well as the South Mokelumne River. The southern border of the Subbasin is comprised of the San Joaquin River, Threemile Slough, and Sevenmile Slough. The geologic structure of the Subbasin is dominated by unconsolidated sand and gravel sedimentary deposits. The bottom of the Subbasin can be defined by the base of fresh groundwater, which varies from under 400 feet below sea level near the southern portion of the proposed subbasin to over 3,200 feet below sea level near the northern portion of the proposed subbasin (Berkstresser, 1973). Further study is needed to more accurately define the bottom of the Subbasin, though it is well understood that there are no geologic faults or folds that restrict groundwater flow in the Northern Delta Subbasin.

F. Notice and Consultation

See attachments for a map and description of affected agencies.
During the GSA formation process as well as the Basin Boundary Modification development process, NDGSA staff did their due diligence to identify local agencies, water systems, and other potentially interested stakeholders. Moreover, the NDGSA leveraged the local knowledge of its members and staff to help identify additional entities. The NDGSA has also conducted outreach and coordination with surrounding GSAs, County agencies, and other identified stakeholders in order to ensure forthright and transparent communication. Further, numerous public and other informal meetings have been held to discuss the proposal with other interested stakeholders.
Letters with a map of the proposed Basin Boundary Modification were sent to all identified entities providing them with information about the proposal. Also, follow up emails and phone calls were made in most cases, and staff made site visits to inform stakeholders and convey information and answer questions. Information on the proposal was posted on the www.NDGSA.org website and interested persons were encouraged to check the website and contact the agency with additional questions. A summary of outreach efforts is attached. Additional letters of support are forthcoming. The NDGSA has also engaged in ongoing communication with surrounding agencies in an effort to organize and harmonize basin boundary requests.
Minutes from four meetings where the proposed basin boundary modification were discussed are attached. There is also an agenda from the most recent NDGSA meeting in July as the Board has not convened since then so minutes from that meeting have not been adopted yet.
The only comments received were letter of support. Those letters are attached as part of Section H.

G. General Existing Groundwater Management

All requests for jurisdictional modification pursuant to Section 342.4 MUST include responses to the following questions.
Sustainable groundwater activities in the three Subbasins affected by the proposed basin boundary modification will all benefit from the proposal because it will lead to more internally homogenous subbasins. The hydrogeologic and landscape conditions in the Northern Delta area are markedly different than the conditions in the region outside of the legal Delta. The existing groundwater subbasin boundaries described in Bulletin 118 do not account for these differences but instead split the Northern Delta region into three different subbasins, lumping the unique Delta landscape in with drier, more upland regions surrounding the legal Delta. This lack of internal homogeneity in the existing subbasins complicates groundwater management actions, as management planning must study and manage the different landscapes independently. Solely considering groundwater conditions, the legal Delta faces much different issues than the surrounding areas. Unlike the surrounding portions of the existing subbasins that have experienced groundwater declines, the proposed Northern Delta Subbasin constitutes a groundwater recharge area due to the high levels of hydrologically connected surface water and the ongoing agricultural irrigation activities that use surface water. For instance, the Alternative Submittal from the Sacramento Central Groundwater Authority identifies the area west of Interstate 5 as a persistent recharge area. Given the high groundwater levels throughout this region, groundwater sustainability management in the legal Delta will not focus on groundwater quantity related undesirable results, in contrast to the surrounding regions. Sustainable groundwater management in this area will focus more on maintaining the current sustainable yield, preventing degradation of the resource, and potentially groundwater quality concerns. Forming a new subbasin will enable the existing groundwater sustainability agencies to more narrowly focus their efforts, thereby achieving more meaningful results. The Northern Delta GSA (NDGSA) is well positioned to take the lead on ensuring that groundwater conditions do not degrade as well as making improvements where there is the potential to do so. The NDGSA is comprised of numerous local agencies engaged in surface water management. As a result of the long-standing relationship with members of the local agencies and local landowners, the NDGSA is ideally situated to productively collaborate with the local landowners to define and remedy any groundwater concerns. The NDGSA has the resources to achieve sustainable management, the Agency recently completed a Proposition 218 process to adopt property-based fees that will fund the necessary sustainable groundwater study, management, and planning activities. The Northern Delta Subbasin basin boundary modification proposal will enable the local stakeholders to focus their attention on this discrete area, quickly responding to changing circumstances in order to maintain sustainability in perpetuity. Furthermore, the more discrete Northern Delta Subbasin will constitute a much more uniform area in terms of hydrogeologic, landscape, societal, and administrative considerations, thus fostering vastly more efficient and effective management activities and laying the groundwork for truly sustainable groundwater management.
See the attachment for an explanation of how the proposed boundary modification would benefit efforts in adjacent groundwater basins to sustainably manage groundwater resources. For additional detail on groundwater management efforts, see Section L Technical Studies.
The proposed Northern Delta Subbasin has not experienced any degree of groundwater overdraft, rather groundwater levels have remained relatively constant. Management of groundwater resources in this region, therefore, have focused on areas around the Northern Delta Subbasin where extractions are greater. Thus, groundwater resources in the surrounding areas have been managed to varying degrees, as previously discussed. Furthermore, the Reclamation, Drainage, and Irrigation Districts that comprise the NDGSA have managed shallow groundwater to varying degrees in order to carry out their larger missions. For information on historic groundwater levels, see the attached figures. For additional information on historic management activities and groundwater level monitoring see Section L and Section M, as well as the associated attachments.
The proposed basin boundary modification would not impact any of the state programs. The CASGEM monitoring entities will not be affected and the existing groundwater management plans do not meaningfully deal with the Northern Delta Subbasin, instead focusing virtually entirely on the areas outside of the Delta. For instance, the attached figure shows the CASGEM monitoring wells in the larger northern Delta region and shows that very few monitoring wells are located within the proposed Northern Delta Subbasin. Therefore, the creation of the Northern Delta Subbasin may improve the existing programs, if it has any impact on them at all. For additional information on historic and ongoing groundwater management and planning activities see Section L and the attachment. For additional information on CASGEM and groundwater characteristics in the region see Section M and the attachment.

H. Local Support

All requests for boundary modification must include the following:
The Northern Delta GSA engaged in concerted outreach efforts to inform the affected entities of the basin boundary modification efforts from the initial stages of the process. Once the Board of Directors formally chose to pursue the creation of the Northern Delta Subbasin--a decision made at one of the recurring public meetings--an outreach letter (attached) and fact sheet (attached) were sent to all identified entities. These outreach materials also directed interested parties to the NDGSA's website, which maintained a page dedicated to the basin boundary modification proposal (attached). Moreover, NDGSA staff actively reached out to parties within the Delta region, both entities affected by the proposal and those unaffected by the proposal, using a variety of means. All outreach efforts included methods for submitting input or inquiries to the NDGSA.
See attachments.
None.
See attachments.

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 the attached file. For additional information on the conditions in the Northern Delta Subbasin, see the attachments in Section L and Section M.

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 NDGSA has worked closely with the surrounding GSAs in conceptualizing this basin boundary modification specifically and groundwater planning activities generally. A representative of the NDGSA frequently attends meetings of the neighboring GSAs in order to maintain clear communication and foster transparency. The NDGSA has not executed many formal coordination agreements to date due to the potential basin boundary modification, though formal status has been provided to two nearby entities to enable them to participate in NDGSA Board discussions. In any event, the Agency fully intends to continue closely coordinating with neighboring entities to collaboratively study, plan, and manage groundwater resources in the region, an intention that is reflected in an MOU with neighboring GSAs in the Solano Subbasin that the NDGSA Board will consider ratifying at a future meeting.

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:
See attachment.
Created on 09/27/2018 at 12:18PM, last modified on 10/31/2018 at 3:34PM and page generated on 07/16/2019 at 3:03AM