B. Description of Proposed Boundary Modification

1. Short Description

   The EMWD requests a basin boundary modification of the DWR Bulletin 118 Basin No. 8-005, the San Jacinto Groundwater Basin, primarily based on scientific (external and internal) justification to better represent the local groundwater aquifer conditions.
2. Type of basin boundary revision

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

   The Eastern Municipal Water District (EMWD) is requesting a modification to the boundary of the San Jacinto Basin 8-005 for scientific external and internal reasons. The modification request is to eliminate areas of the existing Basin that lack viability and/or contribution to the local groundwater aquifer system. The modified boundary will cover areas underlain by permeable materials capable of providing significant quantities of groundwater to wells; eliminate areas underlain by the consolidated bedrock described as having very low water-yielding capability; and exclude areas that do not align with the DWR's definition of an alluvial basin. The proposed Basin boundary will coincide with the surface extent of unconsolidated young alluvium, old alluvium, alluvial fan, valley fill deposits, and other geologic formations having well understood and documented groundwater significance as mapped by the California Geological Survey (CGS). The proposed modification will not impact the sustainable management of the Basin because the areas identified for removal do not provide a significant source of water nor significant volumes of groundwater and there is no current or planned use for these areas that would constitute a significant contribution to water resources. The Basin is the source of groundwater production for EMWD and several other water purveyors. EMWD has been actively managing groundwater in the Basin as part of a voluntary Assembly Bill 3030 effort passed in 1992. EMWD adopted the West San Jacinto Groundwater Basin Management Plan in 1995. The Sustainable Groundwater Management Act (SGMA) was passed in 2014 and required that medium and high priority groundwater basins were managed by Groundwater Sustainability Agencies (GSA). Subsequently, EMWD became the GSA for the west portion of the Basin in 2017, referred to the West San Jacinto GSA, and is comprised of the EMWD Board of Directors. The eastern portion of the Basin is adjudicated. In April 2013, a Stipulated Judgment, Case Number RIC 1207274, was entered with the Superior Court of the State of California for the County of Riverside adopting the Management Plan and creating the Hemet-San Jacinto Watermaster (Watermaster). Stipulated Judgment requires the preparation of an Annual Report by the Watermaster to document activities within the Management Area in a given year. EMWD is contracted by the Watermaster to prepare the Annual Report summarizing activities within the adjudicated area. The Watermaster has been submitting the Hemet-San Jacinto Annual Reports to DWR since 2015 to comply with SGMA requirements for adjudicated basins.

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

   • 8-005 SAN JACINTO
5. Provide the proposed name for the new basin(s) or subbasin(s)

   There are no new proposed basins. After proposed boundary revisions, a single Basin name 8-005 San Jacinto will remain.

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)
   Eastern Municipal Water District	8-005 SAN JACINTO
   Eastern Municipal Water District	8-005 SAN JACINTO

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):

• size: 1
• Attachment D1 - Certification of EMWD.pdf (223kB) Uploaded on 06/25/2018 at 09:06AM

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

Attachment(s):

• size: 1
• Attachment D2 - Resolution 2018-082.pdf (329kB) Uploaded on 06/25/2018 at 02:58PM

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):

• size: 1
• Attachment D3 - Regional_Map_F_-_San_Jacinto_Existing_&_Proposed_Basin_Entity_&_Agency_Map.pdf (4.4MB) Uploaded on 06/27/2018 at 08:25AM

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

Attachment(s):

• size: 1
• Attachment D4 - EMWD_Proposed_New_San_Jacinto_Shapefile.zip (85kB) Uploaded on 06/27/2018 at 09:00AM

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

Attachment(s):

• size: 1
• Attachment D5 - EMWD_Entities_San_Jacinto_Shapefile.zip (171.9kB) Uploaded on 07/12/2018 at 01:25PM

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

This request is not a project as defined in the California Environmental Quality Act Code of Regulations, Title 14, Chapter 3, Section 15378.

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.

The source of the information presented in Attachment E1 is the San Jacinto Groundwater Flow Model Update 2014 (RMC, 2016).

Attachment(s):

• size: 1
• Attachment E1 - EMWD 2014 Hydrogeologic Conceptual Model.pdf (16.9MB) Uploaded on 06/25/2018 at 09:12AM

F. Notice and Consultation

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

Beaumont Cherry Valley Water District Box Springs Mutual Water Company California Department of Fish and Wildlife California Department of Water Resources California State Parks City of Canyon Lake City of Hemet City of Lake Elsinore City of Menifee City of Moreno Valley City of Murrieta City of Perris City of Riverside City of San Jacinto County of Riverside Eastern Municipal Water District Edgemont Community Services District Elsinore Valley Municipal Water District Hemet-San Jacinto Watermaster Lake Elsinore and San Jacinto Watersheds Authority Lake Hemet Municipal Water District Local Agency Formation Commission March Air Reserve Base, Department of Defense March Joint Powers Authority Mead Valley Municipal Advisory Council Metropolitan Water District of Southern California Morongo Band of Mission Indians Nuevo Water Company Pechanga Band of Luiseno Indians Private Groundwater Producers Regional Water Quality Control Board, Santa Ana Region Riverside County Flood Control and Conservation District San Jacinto River Watershed Council Santa Ana River Watermaster Santa Ana Watershed Project Authority Santa Margarita Watermaster Soboba Band of Luiseno Indians Sunnymead Mutual Water Company United States Army Corps of Engineers Valleywide Recreation and Park District West San Jacinto Advisory Committee Western Municipal Water District Western Riverside County Agricultural Coalition Winchester Municipal Advisory Council

Attachment(s):

• size: 1
• Attachment F1 - Basin Boundary Modification Stakeholder List.pdf (86.2kB) Uploaded on 06/25/2018 at 09:21AM

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

On May 9, 2018, a formal letter was sent to each local agency and public water system affected by the basin modification request notifying them of EMWD's intent to request a basin boundary modification and requesting comments regarding the proposed modification (Attachment F2).

Attachment(s):

• size: 1
• Attachment F2 - Potential Mods to the Boundary of the SJ GW Basin & Req for Comments - LHMWD.pdf (147.7kB) Uploaded on 06/25/2018 at 09:34AM

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.

EMWD has worked cooperatively with these entities to initiate and submit this request for basin boundary modification including the Hemet-San Jacinto Watermaster and adjacent Water Agencies. A consultation was held with the California Department of Water Resources, Southern Section on May 29, 2018.

Attachment(s):

• size: 1
• Attachment F2 - Potential Mods to the Boundary of the SJ GW Basin & Req for Comments - LHMWD.pdf (147.7kB) Uploaded on 06/27/2018 at 07:44AM

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.

A public stakeholder meeting was held on May 31, 2018 to discuss the Basin boundary modifications and impacts to several water purveyors (Attachment F3 and F4). The basin boundary modification was discussed at EMWD's Board of Directors meeting on June 20, 2018 (Attachment F5).

Attachment(s):

• size: 3
• Attachment F3 - SJ Basin Modification Presentation_FINAL_20180531.pdf (3MB) Uploaded on 06/25/2018 at 09:40AM
• Attachment F4 - Public Meeting Sign_in Sheet.pdf (46.2kB) Uploaded on 06/25/2018 at 09:46AM
• Attachment F5 - 2018 06-20 Board Agenda.pdf (466.6kB) Uploaded on 06/27/2018 at 12:26PM

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.

In response to EMWD's letter dated May 9, 2016, EMWD received a letter of support from Lake Hemet Municipal Water District (Attachment F6). Attachment F7 - Stakeholder Comment Letter - 28 September, 2018.

Attachment(s):

• size: 2
• Attachment F6 - Basin Boundary Adjustment Support.pdf (63.7kB) Uploaded on 06/25/2018 at 09:47AM
• Attachment F7 - San Jacinto Basin Boundary Modification_Stakeholder Comment_20180928.pdf (11.5MB) Uploaded on 09/28/2018 at 07:38AM

H. Local Support

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

Some individual agencies scheduled one-on-one conference calls and/or meetings to discuss the proposed basin boundary modification including the Watermaster and Lake Hemet Municipal Water District. On May 29, 2018 EMWD met with the California Department of Water Resources, Southern Section. Additionally, EMWD distributed a letter on May 9, 2018, notifying all local agencies and public water systems affected by the proposed basin boundary modification (see Attachment H1).

Attachment(s):

• size: 1
• Attachment H1 - Potential Mods to the Boundary of the SJ GW Basin & Req for Comments - LHMWD.pdf (147.7kB) Uploaded on 06/25/2018 at 09:52AM

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.

In response to EMWD's letter dated May 9, 2016, EMWD received a letter of support from Lake Hemet Municipal Water District (Attachment H2).

Attachment(s):

• size: 1
• Attachment H2 - Basin Boundary Adjustment Support.pdf (63.7kB) Uploaded on 06/25/2018 at 09:53AM

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

None.

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.

A Hydrogeologic Conceptual Model was developed for the San Jacinto Basin in support of the San Jacinto Groundwater Flow Model Update 2014 (Attachment I1). The complete report on the San Jacinto Groundwater Flow Model Update 2014 is included in Section J-Tech. Studies for Sci. External as: J5 - San Jacinto Groundwater Flow Model Update 2014 (and Appendices).

Attachment(s):

• size: 1
• Attachment I1 - EMWD 2014 Hydrogeologic Conceptual Model.pdf (16.9MB) Uploaded on 06/25/2018 at 09:55AM

J. Technical Studies for External Scientific Modifications

1. A qualified map that depicts the lateral boundaries of the aquifers that define the basin or subbasin.

Attachment J1 - San Jacinto Basin 8-005 Geologic Map Attachment J2 - Proposed New San Jacinto Basin 8-005 Geologic Map

Attachment(s):

• size: 2
• Attachment J2 - Regional_Map_G_-_Proposed_San_Jacinto_Basin_Overall_Geologic.pdf (3MB) Uploaded on 06/27/2018 at 08:07AM
• Attachment J1 - Regional_Map_C_-_San_Jacinto_Basin_Overall_Geologic.pdf (3MB) Uploaded on 06/27/2018 at 07:51AM

2. A technical study that provides subsurface data that demonstrates the vertical thickness and relevant physical properties of the alluvial aquifer or stacked series of alluvial aquifers.

J3 - Justification for San Jacinto Groundwater Basin Boundary Modification (and Maps) J4 - Slope Stability and Seepage Evaluation J5 - San Jacinto Groundwater Flow Model Update 2014 (and Appendices) J6 - Scientific Justification - San Jacinto Groundwater Basin Boundary Modification with Attachments_20181019 Attachment 1 - Ground Surface and Bedrock Contours Attachment 2- Alluvium Thickness Rasters

Attachment(s):

• size: 8
• Attachment J3 - Justification for San Jacinto Groundwater Basin Boundary Modification.pdf (255.3kB) Uploaded on 09/18/2018 at 04:21PM
• Attachment J3 - Justification for San Jacinto Groundwater Basin Boundary Modification Maps.pdf (34.5MB) Uploaded on 06/27/2018 at 08:22AM
• Attachment J4 - 15-81-258-01 stability report.pdf (4.9MB) Uploaded on 06/27/2018 at 08:22AM
• Attachment J5 - SJFM-2014-Development and Scenarios-FINAL REPORT - 20160609.pdf (32.2MB) Uploaded on 06/27/2018 at 08:23AM
• Attachment J5 - SJFM-2014-Development and Scenarios-FINAL REPORT - Appendices - 20160609.pdf (34.5MB) Uploaded on 06/27/2018 at 08:23AM
• Attachment J6 - Scientific Justification - San Jacinto Groundwater Basin Boundary Modification with Attachments_20181019.pdf (33.1MB) Uploaded on 10/19/2018 at 01:54PM
• Attachment 1 - Ground Surface_&_Bedrock_Contours.zip (122.8MB) Uploaded on 10/19/2018 at 02:00PM
• Attachment 2 - Alluvium_Thickness_Rasters.zip (13.9MB) Uploaded on 10/19/2018 at 02:00PM

K. Technical Studies for Internal Scientific Modifications

1. A qualified map depicting structural geologic features that could significant impact or impede lateral groundwater flow.

Attachment K1 - Proposed New San Jacinto Basin 8-005 Geologic Map

Attachment(s):

• size: 1
• Attachment K1 - Regional_Map_G_-_Proposed_San_Jacinto_Basin_Overall_Geologic.pdf (3MB) Uploaded on 06/27/2018 at 08:33AM

2. Geologic and hydrologic evidence of groundwater conditions by attaching or providing a URL to any of the following:
   1. Historical and current potentiometric surface maps, groundwater levels, groundwater recharge and discharge areas of the aquifer system within the vicinity of the proposed boundary modification.
   2. Aquifer performance testing results demonstrating basin boundary condition response.
   3. Water quality information of the aquifer system including but not limited to general water quality parameters and isotopic analysis.
   4. Supporting certified geophysical studies.
   5. Any other pertinent information.

Attachment K2 - Justification for San Jacinto Groundwater Basin Boundary Modification Attachment K2 - Justification for San Jacinto Groundwater Basin Boundary Modification Maps Other reference studies include Perris Dam Siting Study and Diamond Valley Lake Dam Siting Study.

Attachment(s):

• size: 2
• Attachment K2 - Justificaiton San Jacinto Groundwater Basin Boundary Modification.pdf (176.6kB) Uploaded on 06/27/2018 at 08:47AM
• Attachment K2 - Justification Maps.pdf (34.5MB) Uploaded on 06/27/2018 at 08:47AM