chowchilla subbasin proposal

PROPOSAL: CHOWCHILLA SUBBASIN

Sustainable Groundwater Management Act (SGMA)

DATA COLLECTION AND ANALYSIS

November 14, 2016

Submitted by

DE-LSCE Team Proposal for SGMA Data Collection and Analysis – Chowchilla Subbasin 2

Table of Contents

Transmittal Letter ..............................................................................................................................1

Section 1: Resources Required and Available to Complete the Work ...................................................2

Section 2: Proposed Scope of Work ....................................................................................................3

Section 3: Cost Summary ....................................................................................................................8

Section 4: Schedule ............................................................................................................................9

Section 5: Additional Information ..................................................................................................... 10

Section 1: Resources Required and Available to Complete the Work The composition and organization of the proposed DE-LSCE Team (Team) is illustrated in the chart on this page. Working under the administrative direction of the County’s project manager, and under the technical direction of the Chowchilla Subbasin Coordinating Committee, our Team would be co-led by the respective presidents of our firms. Grant Davids would take the lead project manager position, as Davids Engineering is the proposed lead firm for contracting and administrative purposes. Vicki Kretsinger Grabert would support Grant with emphasis on direction and coordination of the technical work. Our technical task leaders are Peter Leffler (LSCE), Byron Clark (DE) and Bryan Thoreson (DE), all of whom are professionally registered in their respective disciplines. Nick Watterson, also professionally registered, would support the task leaders and further ensure coordination of day-to-day technical work across the three technical areas, as indicated by the dashed lines between boxes. A pool of subject matter specialists from both firms will be available, as needed, for additional technical support. Resumes of key Team members were previously submitted in our SOQ, and resumes of support staff are available upon request.

Both firms have evaluated workload and staffing in view of the commitments expressed in this proposal, and upon notification of selection, will initiate adjustments in staff assignments so that all proposed Team members will be able to dedicate sufficient time to execute your project on the


proposed schedule, assuming a January 1, 2017 start date.

Our proposed Team has broad technical skills and qualifications to provide the full range of services needed to complete the tasks described in the RFP. Looking beyond the current scope of work, our Team has the capability to support local entities in the Chowchilla and Madera Subbasins in developing Groundwater Sustainability Plans (GSP) as required under SGMA.

We are thoroughly familiar with SGMA and its many components and requirements, and are extensively

involved in SGMA-related work in other groundwater basins in California, particularly in basins with extensive irrigated agriculture and signs of sustainability challenges. We have assembled this Team with capabilities and experience to assist the subbasin in initial efforts towards completion of a GSP, as described in this proposal.

Section 2: Proposed Scope of Work DWR has recently published draft guidance and Best Management Practice (BMP) documents related to GSPs. It should be noted that DWR’s GSP outline includes four distinct components for the Basin Setting section: Hydrogeologic Conceptual Model (HCM), Current and Historical Groundwater Conditions, Water Budget Information, and Management Areas. Although the RFQ/RFP for this project focused primarily on the water budget component and associated data compilation, review, and data gap analysis, our proposal is designed to provide a more complete data compilation/review and data gap analysis that addresses specific GSP requirements for the HCM and groundwater conditions, including the elements outlined in DWR’s BMPs and GSP outline.

The four tasks and related subtasks described below, patterned after those identified in your RFP (see italicized text), describe our technical approach and proposed scope of work. At the conclusion of these tasks, results and recommendations will be presented in a single technical memorandum (TM) consisting of multiple sections and delivery of all acquired data.

Task 1 – Create a Hydrogeologic Conceptual Model of the Subbasin. Task 1 includes developing a conceptual representation of the hydrology of the subbasin recognizing the role of this conceptual model in development of a Groundwater Sustainability Plan (GSP) and DWR’s requirements for the GSP. The conceptual model will account for subsurface and above ground systems and the interaction between the two. Political boundaries created by exclusive and forming Groundwater Sustainability Agencies should be recognized in preparation for the management of these areas in the GSP.

A map showing the Chowchilla Subbasin lateral extent, water supplier service areas, municipalities and primary surface water features is provided in Figure 1. The Team will review the GSP requirements/ components for a hydrogeologic conceptual model (HCM) of the subbasin, as well as provide a preliminary review of historical and current groundwater conditions. This task will focus on characterizing the data available to describe the physical components of the groundwater system and interactions between surface water and groundwater. The preliminary HCM prepared for this task will be described through text and graphics, specifically designed to address the sufficiency of data to meet GSP requirements. The work conducted for this task will consider GSA boundaries and development of potential management

Figure 1: Chowchilla Subbasin Surface Features.


areas. The following subtasks will be performed.

Task 1.1. Develop Narrative Components of HCM. The written portion of the HCM will include evaluation of data collected under Task 3 relative to the following GSP components: (1) regional geologic and structural setting, including the area immediately surrounding the subbasin; (2) lateral basin boundaries and major geologic features that may impact flow of groundwater into and/or out of the subbasin; (3) the vertical (depth) boundary of the subbasin, including the base of fresh water; (4) major aquifers/aquitards, including lateral/vertical extent, aquifer/aquitard properties (e.g., hydraulic conductivity, storativity); and (5) a discussion identifying data gaps and uncertainty in the HCM. Additionally, the written component of the HCM will include a description of data available to address historical and current groundwater conditions, including from January 1, 2015 to present, including data relating to the following: (1) groundwater elevation contours and groundwater hydrographs; (2) change in groundwater storage; (3) groundwater quality (e.g., areas of high salinity and/or known contamination sites/plumes); (4) land subsidence; (5) interconnected surface water features; and (6) identification of groundwater dependent ecosystems. The HCM will utilize existing cross-sections, possibly supplemented by texture data from USGS Central Valley Hydrologic Model (CVHM), maps, and previous reports, including the East San Joaquin Water Quality Coalition Groundwater Quality Assessment Report (GAR), groundwater management plans (GMPs), and USGS reports. An example of the kind of data available from the CVHM, in this case regarding the extent and thickness of the Corcoran Clay layer, is illustrated in Figure 2, below. A preliminary narrative HCM will be prepared that briefly describes each component based on available data/information and the sufficiency of the existing data/information to meet GSP requirements for the narrative portion of the HCM.

Task 1.2. Develop Graphical Components of HCM. GSP requirements for graphical components of the HCM include the following: (1) two or more scaled hydrogeologic cross-sections that depict major stratigraphic and structural features of the subbasin (a sample cross-section developed by LSCE for the Chowchilla Subbasin is provided in Figure 3); (2) topographic map; (3) surficial geologic map that includes cross-section locations; (4) soil survey map; (5) map of major recharge and discharge areas, including wetlands; (6) map of surface water features; (7) map showing source and delivery points for imported surface water supplies; (8) groundwater elevation contour maps; (9)

groundwater hydrographs; (10) change in groundwater storage plot; (11) map showing areas with groundwater quality concerns; (12) map showing areas of land subsidence; and (13) map of interconnected surface water features and groundwater dependent ecosystems. Preliminary graphical components of the HCM will be prepared to the extent possible with existing data, maps, and information. This task will also describe the sufficiency of available data/information to meet GSP requirements for the graphical components of the HCM.

As described above, the Team will review available geologic data, hydrologic data, maps, cross-sections, the GAR, Madera Regional Groundwater Management Plan, and other existing studies to evaluate the sufficiency of existing available data to develop the HCM. To the extent that the data/information necessary to complete one or more of the required elements of the HCM are not readily available from data compiled in

Figure 2: Corcoran Clay Thickness and Cross-Section Location.


Task 3 and information in previous reports, it will be identified as a data gap to be filled in a subsequent phase of work.

Deliverables. Deliverables for Task 1 will include a section of the project TM describing the preliminary hydrogeologic conceptual model for the Subbasin.

Task 2 – Prepare a Conceptual Subbasin Water Budget Model and Time Period for Analysis. Task 2 consists of preparing a conceptual graphic representation of water budget components for the subbasin, to illustrate all of the water accounting centers and all flows into and out of each center. Identify an analysis time period (and time step) which will serve as a baseline of conditions for future projections as well as to represent historical and current subbasin water budgets.

The following subtasks will be performed.

Task 2.1. Develop Initial Water Budget Conceptual Model. The conceptual model for the subbasin water budget will be developed by building upon existing information, described under Task 3. Relevant accounting centers (areas with defined inflows and outflows, including the surface layer and the groundwater system) and flow paths (inflows and outflows) will be identified to ensure compliance with DWR’s final GSP regulations, supporting the required accounting and assessment of the total annual volume of groundwater and surface water entering and leaving the basin, including historical, current and projected water budget conditions, and the change in the volume of water stored. Figure 4, derived from the USGS’s CVHM, depicts an aggregate conceptual water budget for the Chowchilla Subbasin, and serves as an initial, general reference for the work to performed under Task 2.

Task 2.2. Refine Water Budget Conceptual Model. In addition to including accounting centers for the basin as a whole, the surface water system, and the groundwater system, it is anticipated that the budget will be further divided into accounting centers to allow

Figure 3: Example Geologic Cross-Section of the Chowchilla Subbasin.

Figure 4: Example Conceptual Water Budget Figure with CVHM Components (Average 1961-2003).


for separate accounting of water supplies by water source type (e.g., surface water, groundwater, recycled water, etc.) and water uses by water use sector (e.g., urban, agriculture, commercial, environmental, etc.), as required by the GSP regulations. Additional subdivision by management area will be made through consultation with the County and Coordinating Committee if it is determined that water budgets by management area will best support characterization of baseline, historical, and current conditions and support the identification and evaluation of potential projects and management actions to achieve sustainability as part of GSP implementation.

Task 2.3. Define Time Period and Time Step for Analysis. The time period for the water budget and associated data assembly will, at a minimum, meet the requirements of the GSP regulations, which require that the most recent available information be used to characterize current conditions and that the most recent ten years be used to characterize historical conditions. It is anticipated that a longer period of historical conditions will be evaluated as part of the water budget in order to sufficiently describe how past hydrology, water supplies, and water demands have affected aquifer conditions and to best inform the evaluation of sustainability indicators and potential future actions. Available data relating to historical precipitation, evapotranspiration, and stream flow will be used to develop baseline hydrologic conditions to support future projections in accordance with DWR’s BMPs for GSP development.

The time step for the water budget must at a minimum be annual based on the GSP regulations. To support water budget development and evaluation of sustainability indicators and potential projects and management actions, a nominal monthly time step for the water budget is anticipated. Certain surface layer processes, including runoff of precipitation, are often best analyzed using a daily time step, but a daily time step for assembly of the water budget as a whole is not anticipated to be necessary. Ultimately the time step for individual analysis and assembly of the water budget will be selected based on consideration of the flow paths and accounting centers identified, data availability, and consultation with the County and Coordinating Committee.

Deliverables. Deliverables for Task 2 will include a complete conceptual graphical representation of the subbasin water budget and a section of the project TM describing development of the water budget accounting centers and flow paths, selection of the water budget time period, and selection of the analysis time step.

Task 3 – Identify Crucial Data Sets; Compile Existing Data. Task 3 includes identifying data needed to complete a water budget and GSP. This will include compiling existing data and assessing its suitability for the project. Data may be evaluated based on period of record, accuracy, and reliability, etc. The following subtasks will be performed.

Task 3.1. Prepare Inventory of Required Data. An inventory of required data will be prepared, building on the initial inventory listed in Table 1. This inventory is based on prior work by the Team, and indicates that the Team already possesses much of the data to be acquired for this project. Data will be identified and classified by type to support evaluation of each data source and dataset according to its ability to support GSP development and implementation, including the water budget. Data types may include: (1) information describing basin physical characteristics, including lateral and vertical extent of the basin and characteristics of the surface and groundwater systems, including surficial soil characteristics and aquifer features and parameters; (2) political boundaries, including water supplier service areas; (3) groundwater levels, groundwater quality, subsidence, and groundwater-surface water interaction data; (4) land use, irrigation methods and practices, and associated water usage by water use sector (agricultural, urban, etc.) and source (surface water vs. groundwater); (5) surface hydrology, including precipitation, streamflows, diversions and storage, etc.; and (6) historical groundwater development (number and location of wells constructed over time) and well characteristics by type (diameter, depth, etc.) based on well completion databases available from DWR.


Task 3.2. Identify Data Sources, Compile Available Data, and Perform Data Assessment. Following the inventory of data requirements, data sources will be identified, and available data will be compiled and characterized based on evaluation factors developed. For each data type, appropriate evaluation factors will be identified and used to assess suitability for the project. General factors applied to all data sources will include levels of accuracy and precision, accessibility, and past and future reliability. For time series data, the available period of record, frequency of data collection and availability, and periods of missing data will be additionally considered. Each data set will be evaluated relative to the identified factors and an assessment of suitability for the GSP will be performed.

Identification and compilation of datasets will be accomplished by building upon existing information, including existing local and regional groundwater models; groundwater, agricultural, urban, and regional integrated water management plans (GMPs, AWMPs, UWMPs, and IRWMPs, respectively); the GAR prepared previously by LSCE; and other relevant sources identified through coordination with the County and Coordinating Committee. Additional sources of information will be relied upon, including data from DWR, USBR, USGS, NOAA, USDA, local agencies, and others. An example USDA dataset describing 2012 land use within the Chowchilla Subbasin is illustrated in Figure 5, while Figure 6 presents a map of wells with available groundwater level data and associated most recent measurement dates.

Subtask 3.3. Kickoff Meeting. Within approximately 2 to 4 weeks after notice to proceed is issued by the County, the Team will organize and conduct a project kickoff meeting to be held in the Chowchilla area. The purpose of the meeting will be to establish protocols for project direction and communication, collaboratively review and refine the proposed scope of work, and to begin the process of data acquisition. It is expected that the meeting will be scheduled around mid to late January 2017, based on an assumed project start date of January 1, 2017.

Figure 5: Example Land Use Dataset for Chowchilla Subbasin.

Table 1: GSP Data Requirements and Sources.


Deliverables. Deliverables of Task 3 will include a section of a TM documenting the inventory of SGMA required data, summary of data sources by type, development of evaluation factors by data type, and evaluation of data suitability. Additionally, a digital archive of compiled data will be assembled and provided.

Task 4 – Identify and Prioritize Data Gaps. Task 4 consists of identifying and prioritizing data gaps for driving future data collection. Prioritization of data gaps will be based on (1) importance of each identified gap to develop a GSP, HCM, and water budget, and (2) the cost of data collection needed to fill the gaps. The following subtasks will be performed.

Task 4.1. Identify Data Gaps. Building upon Task 3 and analysis of the data as part of HCM and water budget development under Tasks 1 and 2, respectively, data gaps will be identified and prioritized in Task 4. For each data need, the importance of the data for developing the HCM, water budget, and ultimately the GSP will be assessed, as well as the cost of data collection needed to fill the gaps. In evaluating cost, alternative methods of filling each data gap will be qualitatively evaluated.

Task 4.2. Prioritize Data Gaps and Develop Plan to Fill Gaps. Based on the evaluation, data gaps will be prioritized to guide additional data collection. Prioritization of future data collection will be conducted in close consultation with the County and Coordinating Committee. Based on the prioritization, a plan will be developed to support allocation of available resources from local or external funding as the GSP is developed moving forward.

Task 4.3. Progress Meeting. A progress review meeting in the Chowchilla area is proposed after the Team has made substantial progress on all tasks, but before substantial effort has been expended on project documentation. The purpose will be to present and discuss principal findings of the investigations up to that point, and to reach mutual agreement on the content and format on deliverable work products. It is expected that the review meeting will be scheduled around mid-April 2017, based on an assumed start date of January 1, 2017.

Task 4.4. Deliverables. Deliverables of Task 4 will include a section of a TM documenting the evaluation of the importance of each data type with data gaps in supporting SGMA implementation and associated cost, as well as the relative prioritization of each data gap and plan to fill data gaps as part of initial GSP development and in the longer term. The sections from all four tasks will be assembled as a single TM and delivered in draft and final forms.

Section 3: Cost Summary In accordance with instructions in the RFP, our Cost Summary for the proposed Scope of Work is included as a separate submittal. As mentioned in our transmittal letter, we have assumed for purposes of budgeting (and scoping) that the Chowchilla Subbasin project would be conducted independently from the parallel project being conducted in the Madera Subbasin. However, in preparing the scopes of work for both projects, it became apparent that additional benefits would accrue to both subbasins if the projects were technically coordinated. The major objectives of this coordination, beyond addressing critical data gaps,

Figure 6: Availability of Water Level Data for the Chowchilla Subbasin.


would be to advance both subbasins to the same state of readiness to undertake GSP preparation, and to ensure the technical coordination between adjoining Coordinating Committees for the subbasins is as required by SGMA. The potential advantages of a coordinated approach are discussed in our separate Cost Summary; however, we understand that a coordinated approach might not be appealing to both subbasins, and we are therefore prepared to undertake the projects independently, as described in our respective subbasin proposals.

Section 4: Schedule A task-level schedule for the Chowchilla Subbasin project is illustrated below, based on an assumed January 1, 2017 project start date. All three of the core technical tasks (Tasks 1 through 3), would be initiated simultaneously, reflecting the interconnectedness between data collection under Task 3 and development of the HCM (under Task 1) and of the conceptual water budget (under Task 2). The Team’s experience on many similar projects suggests that sufficient time must be allowed for Task 3 data collection, simply because it takes time for data requests to be prepared and answered. Additionally, follow up requests and data clarifications are sometimes necessary once initial responses have been processed. In this case, we are recommending that a full four months be allowed for data collection, with completion of Tasks 1 and 2 to follow about three weeks later. Identification of data gaps under Task 4 would be initiated roughly a month after project startup, and run concurrently with Task 3, as data are identified. Prioritization of data gaps under Task 4 would be conducted beginning about the time Task 3 ends. Proposed project milestones include: a project kickoff meeting about 2 to 4 weeks after project start; a progress review meeting near the completion of data collection, the HCM, and conceptual water budget; submittal of a draft project TM in mid-May and final TM in mid-June; and, submittal of data by the end of June.

This schedule is somewhat longer than the initial schedule the Team submitted in its SOQ, owing to a fuller understanding, based on preparation of this proposal, of the data collection requirements. However, a major project goal, contingent on when notice to proceed is issued, is to position GSAs to proceed with high-priority data collection efforts immediately after GSAs are formally established by June 30, 2017.


Section 5: Additional Information The following statements speak directly to proposed provisions contained in the RFP, indicating the Team’s acceptance of and intent to conform with those provisions.

Agreement for Service. Davids Engineering is proposed to act as prime contractor with the County of Madera, and will enter into a subcontract to engage the services of LSCE. Recognizing that the county’s contract terms will “flow through” to LSCE, both firms have reviewed those terms with respect to insurance coverages, basis of compensation, and indemnification provisions, as articulated in the RFP, and have determined that the proposed terms are acceptable.

Work Product. Both DE and LSCE understand that all work products defined in the scope will be made available to the County in a camera ready format and in electronic formats suitable to the County. However, for work products that are purely electronic and not intended for presentation or illustration, we will want to discuss whether delivery of a camera ready format is necessary and useful. In general, both firms use the Microsoft Office suite for documents, spreadsheets and databases, and ESRI software products for GIS analyses.

Administrative Information. Both DE and LSCE understand that Julia Berry, the County’s Water and Natural Resources Department Director, will serve as Project Manager. We look forward to working closely with Julia, or her designee, primarily for the successful administration of the project, recognizing that technical direction will come primarily from the Chowchilla Subbasin Coordinating Committee. We also accept the County’s provision that all data, documents and other products used or developed during the study will remain the public property of the County of Madera, and will be retained or disposed of as directed by the County. Finally, we acknowledge and accept that the contract entered into with the County will specify a starting date, and will include a termination clause based on substandard performance.

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