B. Description of Proposed Boundary Modification

1. Short Description

   Revise the ext. .boundaries of Basin 8-1 to be consistent with the written description in Bull 118.
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.

   OCWDs Proposed Scientific Modifications to Basin 8-1 Boundaries The boundaries for Basin 8-1 were published in the first Bulletin 118 in 1975 and in subsequent updates in 1980 and 2003. Having carefully reviewed the boundaries established for Basin 8-1 and compared these with more recent and accurately-digitized geologic maps; OCWD staff identified significant offsets and inaccuracies in some areas. These offsets could be due to distortions caused by digitizing paper maps created in the 1970s and then projecting them onto current and more accurate geographic information system (GIS) base maps. OCWD staff considers the offsets and distortions to be significant enough from a scientific perspective to warrant modification to Basin 8-1 boundaries to improve accuracy and consistency with the originally-intended DWR geologic boundaries. To improve the accuracy of the Basin 8-1 boundary, OCWD staff re-digitized the Basin 8-1 boundary to more accurately follow the geologic boundaries using properly georeferenced geologic base maps. The proposed modifications are consistent with the written description of Basin 8-1 in Bulletin 118. Since these modifications are based on geologic and hydrogeologic data, and designed to properly reflect the actual boundaries of the aquifer, the proposed change is properly classified as a scientific boundary modification. Implications of Proposed Boundary Modification For those agencies that do not share a border with Basin 8-1, the proposed Basin 8-1 boundary modification has no impact. For those that do share a border with Basin 8-1, it may mean that the area that required to be managed under the Act is slightly changed. There are no other implications associated with OCWD?s proposed Basin 8-1 boundary modification. The proposed modification will assist in achieving sustainable groundwater management by correctly defining the groundwater basin boundaries. The existing Basin 8-1 boundary includes areas of bedrock and non-alluvial material that do not meet the criteria used to define the extent of a groundwater basin.

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

   • 8-001 COASTAL PLAIN OF ORANGE COUNTY
5. Provide the proposed name for the new basin(s) or subbasin(s)

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)
   La Habra City Of	8-001 COASTAL PLAIN OF ORANGE COUNTY
   Orange County Water District	8-001 COASTAL PLAIN OF ORANGE COUNTY

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):

• ocwd_district_act.pdf (223.9kB) Uploaded on 03/02/2016 at 01:57PM

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

Attachment(s):

• OCWD Resolution to Request Basin 8-1 Boundary Modification.PDF (81.8kB) Uploaded on 03/11/2016 at 01:13PM

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):

• DWRBasin8-1BoundaryModification_Agencies.pdf (5MB) Uploaded on 03/16/2016 at 10:14AM

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

Attachment(s):

• GIS Shapefiles.zip (121.5kB) Uploaded on 03/11/2016 at 11:40AM

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

Attachment(s):

• Adjacent Agencies.zip (282.2kB) Uploaded on 03/16/2016 at 02:18PM

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

Attachment(s):

• CEQA Cat Exemption OCWD Groundwater Basin Boundary Adjustment.pdf (86.6kB) Uploaded on 03/03/2016 at 09:20AM

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 boundaries for Basin 8-1 were published in the first Bulletin 118 in 1975 and in subsequent updates in 1980 and 2003. Having carefully reviewed the boundaries established for Basin 8-1 and compared these with more recent and accurately-digitized geologic maps; OCWD staff identified significant offsets and inaccuracies in some areas. These offsets could be due to distortions caused by digitizing paper maps created in the 1970s and then projecting them onto current and more accurate geographic information system (GIS) base maps. OCWD staff considers the offsets and distortions to be significant enough from a scientific perspective to warrant modification to Basin 8-1 boundaries to improve accuracy and consistency with the originally-intended DWR geologic boundaries. To improve the accuracy of the Basin 8-1 boundary, OCWD staff re-digitized the Basin 8-1 boundary to more accurately follow the geologic boundaries using properly georeferenced geologic base maps. The geologic maps used as data sources include the following: 1. Geologic Map of Orange County California, Showing Mines and Mineral Deposits, by P.K. Morton, R.V. Miller, California Division of Mines and Geology, Bulletin 204, Plate 1, 1981. 2. Geologic Map of the San Bernardino and Santa Ana 30'x60' Quadrangles, California. Compiled by Douglas M. Morton and Fred K. Miller. USGS Open File Report 2006-1217, 2006. Although significant enough to warrant modification, the underlying descriptions of the basin boundaries presented in Bulletin 118 remain valid and are not affected by the proposed changes.

F. Notice and Consultation

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

Attachment(s):

• OCWD Notification List and Map.pdf (757.2kB) Uploaded on 03/03/2016 at 09:21AM

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

All 19 groundwater retail agencies within OCWD were notified along with the Municipal Water District of Orange County. GIS was used to identify other local agencies within or adjacent to the Basin 8-1 boundary.

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.

All identified affected agencies were sent a letter via certified mail. A typical letter is attached. Note the CC list for others that were sent the same letter.

Attachment(s):

• IRWD Notification Letter_DWR Basin 8-1 Boundary Mod.pdf (7.9MB) Uploaded on 03/03/2016 at 09:24AM

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.

Attachment(s):

• List of Meetings_Notifications Re Proposed Basin 8-1 Boundary Modification.pdf (18.8MB) Uploaded on 03/03/2016 at 09:26AM

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.

Attachment(s):

• Comments on OCWDs Basin Modification Request.pdf (8.9MB) Uploaded on 03/15/2016 at 10:17AM

H. Local Support

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

As described under Notice and Consultations, letters about the proposed boundary modification were sent out to affected agencies via certified mail. Information about the proposed boundary modification was posted on the OCWD website. OCWD held a public meeting to describe the proposed modification and receive comments. OCWD engaged several agencies directly, including the Water Replenishment District of Southern California, La Habra, and City of Corona.

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.

Attachment(s):

• Comments on OCWDs Basin Modification Request.pdf (8.9MB) Uploaded on 03/15/2016 at 10:17AM

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

By collaborating with La Habra and City of Corona and modifying the boundaries to address their concerns, there is no opposition to the proposed boundary modification.

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 boundary modification does not affect the current hydrogeologic conceptual model in Bulletin 118. A full description of the groundwater basin can be found in Section 3 of OCWD"s Groundwater Management Plan (GWMP). The GWMP can also be found at www.ocwd.com.

Attachment(s):

• Section 3 Basin Hydrogeology from OCWD GWMP 2015 FINAL.pdf (4.5MB) Uploaded on 03/29/2016 at 01:29PM

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.

To improve the accuracy of the Basin 8-1 boundary, OCWD staff re-digitized the Basin 8-1 boundary to more accurately follow the geologic boundaries using properly georeferenced geologic base maps. The geologic maps used as data sources include the following: 1. Geologic Map of Orange County California, Showing Mines and Mineral Deposits, by P.K. Morton, R.V. Miller, California Division of Mines and Geology, Bulletin 204, Plate 1, 1981. 2. Geologic Map of the San Bernardino and Santa Ana 30'x60' Quadrangles, California. Compiled by Douglas M. Morton and Fred K. Miller. USGS Open File Report 2006-1217, 2006. http://pubs.usgs.gov/of/1999/of99-172/ and http://pubs.usgs.gov/of/2006/1217/of2006-1217_map/of2006-1217_geol_map.pdf

Attachment(s):

• DWRBasin8-1BoundaryModification_geology_final.pdf (14.2MB) Uploaded on 03/16/2016 at 10:12AM

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 proposed boundary modification does not affect the current hydrogeologic conceptual model in Bulletin 118. For more information on the basin hydrogeology, see OCWD's Groundwater Management Plan. Link to the plan on OCWD's website is provided below. Section 3, Hydrogeology, is attached. http://www.ocwd.com/media/3622/groundwatermanagementplan2015update_20150624.pdf

Attachment(s):

• Section 3 Basin Hydrogeology from OCWD GWMP 2015 FINAL.pdf (4.5MB) Uploaded on 03/29/2016 at 01:29PM