B. Description of Proposed Boundary Modification

1. Short Description

   Modify eastern Llagas Subbasin boundary to match extent of water-bearing sediments as mapped by USGS
2. Type of basin boundary revision

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

   This proposed modification to the boundary of the Llagas Subbasin will restore its eastern edge to that more closely depicted and described in the Department of Water Resources (DWR) 1981 Bulletin 118-1,Volume IV: Evaluation of Ground Water Resources, South San Francisco Bay: South Santa Clara County Area. The modified boundary encompasses only areas underlain by permeable materials capable of providing significant quantities of water to wells; eliminates areas underlain by rocks described as having very low water-yielding capability; and generally coincides with the surface extent of 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) and U.S. Geological Survey (USGS). The proposed modification will not impact sustainable groundwater management as the area proposed to be removed does not contain significant quantities of groundwater and the District has no current or planned activities in the area.

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

   • 3-003.01 GILROY-HOLLISTER VALLEY - LLAGAS AREA
5. Provide the proposed name for the new basin(s) or subbasin(s)

   3-03.01 GILROY-HOLLISTER VALLEY - LLAGAS SUBBASIN

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)
   Santa Clara Valley Water District	3-003.01 GILROY-HOLLISTER VALLEY - LLAGAS AREA

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):

• D1_District_Act.pdf (403.1kB) Uploaded on 03/29/2016 at 04:17PM

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

Attachment(s):

• D2_Resolution_DWR_Modify_Boundary_Llagas_Subbasin.pdf (937.9kB) Uploaded on 03/29/2016 at 04:17PM

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):

• D3_D5_Affected_Agency_System.pdf (831.3kB) Uploaded on 03/29/2016 at 04:19PM

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

Attachment(s):

• D4_Boundary_Shapefiles.zip (37.7kB) Uploaded on 03/30/2016 at 01:24PM

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

Attachment(s):

• D5_Affected_Agency_System.zip (50.7kB) Uploaded on 03/30/2016 at 01:51PM

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

This proposed modification is not subject to CEQA because it can be seen with certainty that there is no possibility that the activity in question may have a significant effect on the environment (Section 15061(b)(3) of the CEQA Guidelines), as the areas proposed for exclusion from the basin boundary overlie bedrock, and the District does not and is not planning to conduct groundwater management activities in the excluded areas. There are no direct physical changes associated with the project as the revision of the boundary would only be reflected in an updated version of Bulletin 118. Also, there would not be any indirect physical changes associated with the project. The District does not and is not planning to conduct groundwater management activities in the areas proposed for exclusion from the basin boundary revision. As stated above, the current boundary overlies bedrock and does not correspond to the water-bearing sediments that the District actively manages. The areas proposed for exclusion do not affect the District?s ability to sustainably manage the Llagas Subbasin and, as such, the District has not historically conducted groundwater management activities in the areas at issue and would not plan to do so should the boundary revision request be denied by DWR. Because the boundary revision would not affect the District?s historical or planned management activities, and would not affect the District?s ability to sustainably manage the subbasin, the request and potential revision would not result in any adverse changes in the physical conditions of the environment.

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.

See attached response.

Attachment(s):

• E1_Response.pdf (26.9kB) Uploaded on 04/04/2016 at 02:49PM
• X_Sections_Olin_Basin_Characterization.pdf (2.1MB) Uploaded on 03/29/2016 at 04:54PM
• DWR_ b118_1_vol4_X_Sections.pdf (543.6kB) Uploaded on 03/29/2016 at 04:54PM

F. Notice and Consultation

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

City of Morgan Hill County of Santa Clara Oak Springs Mutual Water Company

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

a) The District permits all wells installed in Santa Clara County and assesses a groundwater production charge for wells benefiting from District groundwater management programs. These records were searched for well owner and location information. b) The well locations and the current and proposed boundaries of the Llagas Subbasin were mapped using GIS. c) The California Division of Drinking Water (DDW) online records regarding public water systems were searched for systems located within Santa Clara County to identify systems within the Llagas Subbasin and affected 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.

a) District staff spoke to the director of the Oak Springs Mutual Water Company on February 10, 2016. b) District staff sent an e-mail with information regarding the proposed boundary modification to the District?s Water Retailers Groundwater Subcommittee on February 16, 2016 (Attachment F-3). c) District staff spoke with Anthony Eulo with the City of Morgan Hill on February 17, 2016. d) District staff sent an email to Santa Clara County Planning and Department of Environmental Health staff on February 19, 2016 (Attachment F-3). e) The District mailed information on the proposed boundary revision to Oak Springs Mutual Water Company, City of Morgan Hill, and Santa Clara County Planning and Environmental Health Departments on March 8, 2016 (Attachment F-3).

Attachment(s):

• Feb_16_GW_Sub_Email.pdf (1.1MB) Uploaded on 03/29/2016 at 05:01PM
• Feb_17_MH_Phone_Call.pdf (54.3kB) Uploaded on 03/29/2016 at 05:01PM
• Feb_19_SCC_Email.pdf (60.4kB) Uploaded on 03/29/2016 at 05:01PM
• Mar_8_Morgan_Hill_Letter.pdf (600kB) Uploaded on 03/29/2016 at 05:01PM
• Mar_8_Oak_Springs_Water_Letter.pdf (631.1kB) Uploaded on 03/29/2016 at 05:01PM
• Mar_8_SCCDEH_Letter.pdf (611.1kB) Uploaded on 03/29/2016 at 05:01PM
• Mar_8_SCCPlanning_Letter.pdf (606.1kB) Uploaded on 03/29/2016 at 05:01PM

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.

On February 23, 2016, the District Board of Directors considered a Proposed Modification to the Boundary of the Llagas Subbasin (Item 3.2) at a regularly scheduled meeting, which includes a 10-day posting period (Attachment F-4). The District Board concurred with the staff recommendation to submit the initial notification regarding basin boundary exploration to DWR. Under item 5.3 at a regularly scheduled meeting of the District Board of Directors on March 22, 2016, the District Board adopted a Resolution to Initiate a Request to the Department of Water Resources (DWR) to Modify the Boundary of the Llagas Subbasin, DWR Basin 3-3.01 (Attachment F-4). The agenda for this meeting included a 10-day posting period.

Attachment(s):

• Feb_23_Agenda.pdf (1.8MB) Uploaded on 03/29/2016 at 05:02PM
• Mar_22_Board_Mtg_Agenda.pdf (16.8MB) Uploaded on 03/29/2016 at 05:02PM

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.

One comment was submitted to the District Board on the March 22, 2016 item for the resolution to support the basin boundary modification request (Attachment F-5). The comment submitted was on DWR prioritization criteria rather than the boundary modification request, and the District response was included in the comment.

Attachment(s):

• F5_Public Comment.pdf (459.9kB) Uploaded on 03/29/2016 at 05:04PM

H. Local Support

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

As described in Section F.3, the District notified agencies and public water systems overlying the area proposed for modification by phone and letter. Additionally, information on the proposed modification has been available since February 17, 2016 on the District website at www.valleywater.org/GroundwaterManagement. Additional notifications will be sent to public systems within the Llagas Subbasin as required once DWR deems the application to be complete.

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.

No comments from the affected agencies or systems have been received.

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

N/A

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.

See attached file

Attachment(s):

• Llags_Recharge_Area_Water_Bodies.pdf (984.7kB) Uploaded on 03/30/2016 at 10:24AM
• Hydrogeologic_Conceptual_Model.pdf (26kB) Uploaded on 03/30/2016 at 10:07AM

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.

See attached map

Attachment(s):

• Qualified_Map.pdf (923.1kB) Uploaded on 03/30/2016 at 10:31AM

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.

The studies referenced below demonstrate the vertical thickness and relevant aquifer properties and are attached to the request. California Department of Water Resources, Evaluation of Groundwater Resources South San Francisco Bay Volume IV South Santa Clara County Area: Bulletin 118-1, May 1981 California Geological Survey (CGD), Regional Geologic Maps (RGM) Series (250k scale, 1981 ? present) California State Water Resources Control Board, California GAMA Program: Sources and Transport of Nitrate in Shallow Groundwater in the Llagas Basin of Santa Clara County, California, 2005 CH2M Hill, Llagas Basin Numerical Groundwater Model, 2005 Lawrence Livermore National Laboratory, California Aquifer Susceptibility - A Contamination Vulnerability Assessment for the San Clara and San Mateo County Groundwater Basins, 2002 MACTEC Engineering and Consulting for Olin/Standard Fusee, Llagas Subbasin Characterization, Morgan Hill, California , Santa Clara County, 2006 Santa Clara Valley Water District, 2012, Groundwater Management Plan USGS, Professional Paper 943, Flatland Deposits ? Their Geology and Engineering Properties and their Importance to Regional Planning, 1979 USGS, Open File Report 00-444, Preliminary Maps of Quaternary Deposits and Liquefaction Susceptibility, Nine-County San Francisco Bay Region, California, 2000

Attachment(s):

• USGS Open File Report 00-444.url (183B) Uploaded on 03/30/2016 at 10:34AM
• Final_2012_GWMP.pdf (18MB) Uploaded on 03/30/2016 at 10:32AM
• DWR_individual_basin_descriptions_llagas_3_3.01.pdf (138.3kB) Uploaded on 03/30/2016 at 10:32AM
• Flatland Deposits_ San Francisco Bay Region.pdf (77.2MB) Uploaded on 03/30/2016 at 10:33AM
• USGS_OFR_98_795.pdf (17.2MB) Uploaded on 03/30/2016 at 10:36AM
• Llagas_GW_Flow_Model_Documentation.pdf (145.7MB) Uploaded on 03/30/2016 at 10:35AM
• BasinChar_2007.zip (69.5MB) Uploaded on 03/30/2016 at 10:41AM
• BasinChar_2008.zip (113.4MB) Uploaded on 03/30/2016 at 10:42AM
• BasinChar_2009.zip (69.8MB) Uploaded on 03/30/2016 at 10:43AM