B. Description of Proposed Boundary Modification

1. Short Description

   The proposed El Casco Basin is a jurisdictional modification of the San Timoteo Basin (8-2.08).
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 basin boundary modification of the El Casco Basin is consistent with the San Timoteo Management Zone established by the Santa Ana Regional Water Quality Control Board pursuant to the 2004 Basin Plan Amendment. The responsibility for salinity management, nutrient management, adaptive habitat plan, and groundwater sustainability is the primary responsibility of the Yucaipa Valley Water District.

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

   • 8-002.08 UPPER SANTA ANA VALLEY - SAN TIMOTEO
5. Provide the proposed name for the new basin(s) or subbasin(s)

   The proposed name of the new groundwater basin boundary area is the El Casco Basin.

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)
   Yucaipa Valley Water District	8-002.08 UPPER SANTA ANA VALLEY - SAN TIMOTEO
   Beaumont-Cherry Valley Water District	8-002.08 UPPER SANTA ANA VALLEY - SAN TIMOTEO
   Eastern Municipal Water District	8-002.08 UPPER SANTA ANA VALLEY - SAN TIMOTEO

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):

• YVWD Statutory.pdf (5MB) Uploaded on 03/31/2016 at 02:57PM

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

Attachment(s):

• YVWD Resolution 2016-12.pdf (134.6kB) Uploaded on 03/31/2016 at 02:57PM

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):

• BasinsV4_YVWD_ElCasco_Aerial.pdf (7MB) Uploaded on 03/31/2016 at 02:55PM

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

Attachment(s):

• El_Casco.zip (8.8kB) Uploaded on 03/31/2016 at 04:35PM

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

Attachment(s):

• YVWD_Sphere.zip (13.6kB) Uploaded on 03/31/2016 at 04:32PM

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

The Yucaipa Valley Water District is the responsible agency pursuant to the California Environmental Quality Act.

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 Proposed El Casco Groundwater Basin partially covers two USGS quadrangle maps, the El Casco and the Redlands Quad Maps. The western portion of the proposed boundary is within the Township 2 South and Range 3 West. The central portion of the proposed boundary is within Township 2 South and Range 2 West. The eastern portion of the proposed boundary is within Township 3 South and Range 1 West.

F. Notice and Consultation

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

The local agencies and public water system that may be affected by the basin modification request includes the City of Redlands.

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

The Yucaipa Valley Water District has been actively monitoring the El Casco basin for the past decade. During this time, the Yucaipa Valley Water District has engaged numerous resource agencies, private property owners and interested parties about various issues in the immediate area.

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.

Prior to submitting the basin modification request, the Yucaipa Valley Water District has been actively involved in local meetings as well as regional meetings with the San Bernardino Valley Municipal Water District and the Beaumont Basin Watermaster to coordinate the basin modification filings.

Attachment(s):

• 16-023 Presentation - Sustainable Groundwater Management Act & CASGEM.pdf (2.2MB) Uploaded on 03/31/2016 at 03:32PM
• 16-028 - SGMA - El Casco Basin.pdf (1.4MB) Uploaded on 03/31/2016 at 03:33PM
• 15-235 Presentation - Sustainable Groundwater Management Act & CASGEM.pdf (2.2MB) Uploaded on 03/31/2016 at 03:33PM
• 16-05 Sustainable Groundwater Managment Act.pdf (3.6MB) Uploaded on 03/31/2016 at 03:34PM

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.

The Yucaipa Valley Water District initiated meetings with water retailers in the region to discuss the proposed basin modifications. These discussions included presentations at YVWD regular meetings; meetings of the San Gorgonio Pass Regional Water Alliance; and manager meetings of the Regional Water Resource Coordination group.

Attachment(s):

• Notification of Meetings - SGMA.pdf (529.1kB) Uploaded on 03/31/2016 at 04:45PM
• 160224 Regional Water Resource Coordination Meeting.docx (23.2kB) Uploaded on 03/31/2016 at 03:26PM
• 160128 Regional Water Resource Coordination Meeting.docx (23.3kB) Uploaded on 03/31/2016 at 03:25PM
• 160330 Regional Water Resource Coordination Meeting.docx (23.4kB) Uploaded on 03/31/2016 at 03:26PM
• _ 160127 SGRWRA Agenda.docx (924.2kB) Uploaded on 03/31/2016 at 03:27PM

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.

No comments were received regarding the proposed boundary modification.

G. General Existing Groundwater Management

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

On January 22, 2004, the Santa Ana Regional Water Quality Control Board adopted Resolution No. R8-2004-0001 that amended groundwater subbasin boundaries in the area of the proposed El Casco Basin. On April 24, 2014 the Santa Ana Regional Water Quality Control Board adopted Resolution No. 2014-0005 Amending the Water Quality Control Plan for the Santa Ana Region. Both of these documents set forth the water quality objectives for the San Timoteo Basin which will be renamed as the El Casco Basin as a result of the proposed basin modification process. These documents specifically require the Yucaipa Valley Water District to actively manage the water quality and water resources in the immediate area of the proposed El Casco Basin.

Attachment(s):

• 04_001.pdf (3.9MB) Uploaded on 03/31/2016 at 03:44PM
• Resolution 14_005_BPA_WQCP_Salt_Mngmt_Plan.pdf (975.8kB) Uploaded on 03/31/2016 at 03:42PM

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

The Yucaipa Valley Water District is coordinating this basin modification request with the Beaumont Cherry Valley Water District and the San Bernardino Valley Municipal Water District to ensure that the proposed basin modification is coordinated with the adjacent groundwater basins.

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

The proposed El Casco Basin is a relatively narrow groundwater basin in the San Timoteo Formation. This area is recharged by the San Timoteo Creek and upstream tributaries in the City of Beaumont. As a result of precipitation, the groundwater elevations in the El Casco Basin are extremely close to the surface. With the current drought conditions and increased agricultural uses, the groundwater elevations are beginning to decline in recent years.

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 proposed El Casco basin is such an important component of the Yucaipa Valley Water District's regulatory requirements, the basin modification will provide an opportunity for the collection of groundwater levels that will be included in SARWQCB reporting and the California Statewide Groundwater Elevation Monitoring (CASGEM). This new basin will also be part of a new Groundwater Sustainability Plans developed pursuant to the Sustainable Groundwater Management Act.

H. Local Support

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

The Yucaipa Valley Water District has conducted numerous publicly noticed meetings to review the proposed basin modifications. Copies of the staff reports and the dates of the meetings are attached as supporting documentation.

Attachment(s):

• 16-028 - SGMA - El Casco Basin.pdf (1.4MB) Uploaded on 03/31/2016 at 03:56PM
• 15-235 Presentation - Sustainable Groundwater Management Act & CASGEM.pdf (2.2MB) Uploaded on 03/31/2016 at 03:57PM
• 15-144 Presentation - Sustainable Groundwater Management Act & CASGEM.pdf (1.4MB) Uploaded on 03/31/2016 at 03:57PM
• _ 160127 SGRWRA Agenda.pdf (122.5kB) Uploaded on 03/31/2016 at 03:57PM

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.

The Yucaipa Valley Water District has not received comments or documents in support or in opposition to the proposed basin modification.

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

Not applicable.

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 proposed El Casco basin is in a valley canyon in the far northwestern foothills of the San Jacinto Mountains, in the Inland Empire region of Southern California. The canyon runs from its southern inflow mouth in Beaumont in Riverside County, in a northwest alignment, to its northern outflow mouth west of Redlands and east of Loma Linda in San Bernardino County. San Timoteo Creek formed the canyon, and flows northwest through it to its confluence with the Santa Ana River, being a tributary of it. The creek drains the Banning Valley west of the San Gorgonio Pass water divide, and the watersheds of the San Bernardino and San Jacinto Mountains that feed into it. San Timoteo Creek exhibits deeply incised channels with nearly vertical banks that regularly slough off blocks or slabs of sediment. The sediment lands in the channel bottom and is transported downstream by storm events. The natural recharge for the El Casco Basin includes areal recharge and stream channel percolation. Areal recharge and stream channel percolation was estimated to be 2,700 acre-ft/yr and 1,300 acre-ft/yr, respectively (DWR, 1986). Underflow inflow from the Beaumont Management Zone to the El Casco Basin was based on the Beaumont Management Zone study (GEOSCIENCE, 2012). The underflow inflow was estimated to range from 1,568 acre-ft to 2,446 acre-ft with an annual average of 1,814 acre-ft/yr during the period from 2012 to 2031.

Attachment(s):

• report-1.pdf (643.1kB) Uploaded on 03/31/2016 at 04:27PM
• plate-1.pdf (3MB) Uploaded on 03/31/2016 at 04:27PM
• plate-2.pdf (2.1MB) Uploaded on 03/31/2016 at 04:27PM
• red_map.pdf (3.1MB) Uploaded on 03/31/2016 at 04:32PM
• 120718_FINAL-Rech-Coop-Agrmnt_Yucaipa_SanTimoteo.pdf (18.2MB) Uploaded on 03/31/2016 at 04:13PM
• ea.pdf (3.6MB) Uploaded on 03/31/2016 at 04:11PM

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):

• plate-1.pdf (3MB) Uploaded on 03/31/2016 at 04:28PM
• plate-2.pdf (2.1MB) Uploaded on 03/31/2016 at 04:28PM
• report-1.pdf (643.1kB) Uploaded on 03/31/2016 at 04:28PM
• Resolution 14_005_BPA_WQCP_Salt_Mngmt_Plan.pdf (975.8kB) Uploaded on 03/31/2016 at 03:42PM
• 04_001.pdf (3.9MB) Uploaded on 03/31/2016 at 03:44PM

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

The Yucaipa Valley Water District will coordinate with upstream project participants like the Beaumont Basin Watermaster, City of Beaumont, Beaumont Cherry Valley Water District as well as coordinate with downstream project participants like the City of Redlands and the San Bernardino Valley Municipal Water District.