Prepared for: Prepared by:
CITY OF GONZALES
WATER SUPPLY
ASSESSMENT
FOR
Puente del Monte
and
Vista Lucia
FINAL DRAFT
December 2020
Exhibit J
7433 N. First St, Suite 103 • Fresno, CA 937 20 • Tel (559) 436-0600 • Fax (559) 436-0622 www.akeleng.com
December 16, 2020
EMC Planning Group Inc.
301 Lighthouse Ave, Suite C
Monterey, CA 93940
Attention: Stuart Poulter, Associate Planner
Subject: Puente del Monte and Vista Lucia – Water Supply Assessment (SB 610 Requirements)
Dear Stuart:
We are pleased to submit this Water Supply Assessment (WSA) report for the Puente del Monte and Vista Lucia developments. This report is intended to satisfy the requirements of SB 610 by evaluating the impact of this project on existing and future water supplies.
The report quantifies this project’s water supply requirements, potential impact on the City’s supply availability, discussions on the supply reliability, and supply vs. demand comparisons.
We are extending our thanks to you, Ron Sissem, and Terri Wissler Adam for your valuable input and reviews during the completion of this study.
Sincerely,
AKEL ENGINEERING GROUP, INC.
Tony Akel, P.E.
Principal
Enclosure: Report
Smart Planning Our Water Resources
December 2020 i Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonzales
Puente del Monte and Vista Lucia
Water Supply Assessment
Table of Contents
Page No.
1.0 PURPOSE ................................................................................................................... 1
2.0 RELEVANT REPORTS ............................................................................................... 1
3.0 PROJECT DESCRIPTION .......................................................................................... 2
4.0 CONCEPTUAL LAND USE PLANS ............................................................................ 2
5.0 PROJECT WATER DEMANDS ................................................................................... 3
5.1 Comparison of Gross Project Water Demands with 2019 WMP Assumptions .. 3
5.2 Comparison of Gross Project Water Demands with Potential Agricultural Use . 4
5.3 Net Water Demand Analysis ............................................................................. 5
5.3.1 Future Development Conditions – Puente del Monte ............................... 5
5.3.2 Future Development Conditions – Vista Lucia ......................................... 6
5.3.3 Future Development Conditions – Puente del Monte and Vista Lucia ..... 6
6.0 GROUNDWATER BASIN ............................................................................................ 6
7.0 WATER SUPPLY RELIABILITY .................................................................................. 7
7.1 Groundwater Supply Facilities ........................................................................... 7
7.2 Supply during Single Dry and Multiple Dry Years ............................................. 7
8.0 RECYCLED WATER ................................................................................................... 8
9.0 SUPPLY AND DEMAND COMPARISON .................................................................... 8
10.0 SUMMARY .................................................................................................................. 8 Tables
Table 1 Conceptual Land Use Plan Inventory
Table 2 Planned Development Comparison
Table 3 Comparison of Gross Project Water Demands with 2019 Water Master Plan Table 4 Comparison of Gross Project Water Demand with Agricultural Water Demands Table 5 Net Water Demand Analysis
Table 6 Existing Water Supply Facilities
Table 7 180/400-Foot Subbasin Sustainable Yield
Table 8 Eastside Subbasin Groundwater Budget
Figures
Figure 1 Location Map
Figure 2 Conceptual Land Use Plans
Figure 3 Agricultural Lands
Figure 4 Groundwater Basins
Figure 5 Existing Groundwater Wells
December 2020 ii Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
Appendices
APPENDIX A – Conceptual Land Use Planning Information
December 2020 1 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonzales
PUENTE DEL MONTE AND VISTA LUCIA - WATER SUPPLY
ASSESSMENT
1.0 PURPOSE
This Water Supply Assessment (WSA) report for the Puente Del Monte and Vista Lucia Annexation Areas (Project) is intended to satisfy the requirements of Senate Bill (SB) 610 by evaluating the impact of this Project’s water demands on the water supplies through a 20-year horizon, as stipulated in the SB 610 requirements.
The report includes a discussion of this project’s water supply requirements and potential impact on the City’s supply availability. This report references multiple land use planning and groundwater supply documents, including the 2019 Water Master Plan (2019 WMP), the 2020 180/400-Foot Aquifer Subbasin Groundwater Sustainability Plan (180/400-Foot GSP), and the draft Salinas Valley Basin Groundwater Sustainability Agency Integrated Sustainability Plan (SVBGSA ISP).
2.0 RELEVANT REPORTS
Several reports provide detail information and factual data related to this analysis. Exhibits from these reports were included in the appendices for ease of referencing. City of Gonzales Water Master Plan, November 2019. The City’s 2019 Water Master Plan presents historical and projected water demands, identifies existing and future water system capacity deficiencies, recommends projects to correct these deficiencies, and identifies major water facilities for servicing future developments. City of Gonzales Wastewater Master Plan, December 2019. The City’s 2019 Wastewater Master Plan presents historical and projected wastewater, identifies existing and future water system capacity deficiencies, evaluates wastewater treatment alternatives, explores possible recycled water opportunities, and recommends improvements to mitigate existing system deficiencies and service future growth. 180/400-Foot Aquifer Subbasin Groundwater Sustainability Plan, January 2020. This Groundwater Sustainability Plan fulfills the requirements of the 2014 California Sustainable Groundwater Management Act (SGMA) for the Salinas Valley 180/400 Foot Aquifer Subbasin and summarizes plans to achieve groundwater sustainability in 20 years and maintain sustainability for an additional 30 years.
Draft Salinas Valley Basin Groundwater Sustainability Agency Integrated Sustainability Plan, January 2019. This Integrated Sustainability Plan, prepared by the December 2020 2 Puente del Monte and Vista Lucia WSA
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Salinas Valley basin Groundwater Sustainability Agency, documents the characteristics of the Salinas Valley Groundwater Basin and its six subbasins, establishes local sustainable management criteria, and identifies projects intended to achieve sustainability throughout the basin by the year 2040. This report is still in the process of being completed and draft chapters were used as available.
DWR Bulletin 118 – Eastside Aquifer Subbasin , February 2004. This groundwater report prepared by the Department of Water Resources (DWR) summarizes the boundaries and hydrogeological characteristics of the Eastside Aquifer Subbasin of the Salinas Valley Groundwater Basin. This report also includes information regarding historic trends in groundwater levels, storage, and quality. It also includes information regarding a 1998 groundwater budget prepared for the subbasin.
Puente del Monte Land Use Plan, October 2020. This land use plan documents the planned future land use within the Puente del Monte annexation area. This land use is used to estimate future water demands.
Vista Lucia Land Use Plan, November 2019. This land use plan documents the Vista Lucia development, including planned future land use. This land use is used to estimate future water demands.
3.0 PROJECT DESCRIPTION
The Project Area includes two planned areas of annexation: the Puente del Monte development and the Vista Lucia development. These developments are briefly described as follows:
Puente del Monte: Puente del Monte is comprised of approximately 585 acres of residential, commercial, industrial, mixed use, and park land use types east of Highway 101 along Gloria Road. The existing land use currently consists of agricultural lands. This development was documented in the City’s 2019 WMP, though the current conceptual land use plan has differing land uses than the 2019 WMP.
Vista Lucia: Vista Lucia, subdivided into Village One and Village Two, is comprised of approximately 770 acres of residential, commercial, school, and park land use types south of Associated Lane between Fanoe Road and Iverson Road. The existing land use consists of agricultural lands. This development was documented in the City’s 2019 WMP, though the current conceptual land use plan has differing land uses than the 2019 WMP.
4.0 CONCEPTUAL LAND USE PLANS
The conceptual land use plan areas are generally located outside the existing City limits, but inside the sphere of influence as defined in the 2019 WMP, as shown on Figure 1; approximately 41 acres of Puente del Monte, adjacent to Highway 101, are within the existing City limits The December 2020 3 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
existing land use consists of approximately 1,350 acres of agricultural and open space land uses (Table 1). The City’s existing General Plan land use map designates the project sites as various land uses, including residential, public facility, commercial, and other non-residential types.
The 2019 WMP documented the buildout land use of the sites as various residential densities, commercial, industrial, public facilities, and open space. The residential units and non-residential acreages for the project site vary between the 2019 WMP and the current conceptual land use plans , as summarized on Table 2. The land use inventory summarized on Table 2 was developed from land conceptual land use plan information provided by EMC Planning Group staff, which is included in Appendix A.
5.0 PROJECT WATER DEMANDS
The projected water demands in the currently adopted water system master plan 2019 WMP were based on land use demand factors. These demand factors assumed a household occupancy of
3.74 people per household, which was based on the 2010 General Plan Land Use Element and assumed a 3.0% vacancy rate. However, to account for current housing trends City of Gonzales staff have indicated that a household occupancy of 4.4 people per household, based on the 2015 Housing Element, should be used for demand planning purposes. The demand factors have been updated accordingly.
The land use types and acreages of the planned development areas differ from those identified in the current conceptual land use plans, as summarized in the following sections
5.1 Comparison of Gross Project Water Demands with 2019 WMP Assumptions
The 2019 WMP included water demand projections for the area to be developed, which differ compared to the conceptual land use plan. The following sections summarize these differences and compare the demands based on the 2019 WMP and the conceptual land use plan. It is assumed that the water use based on the most recent conceptual land use plan will supersede the estimates previously provided in the 2019 WMP. Additionally, the conceptual land use plans will be used for estimating the effects on the water supply. The results of this water use comparison are documented on Table 3 and documented below. Baseline Water Demands – 2019 WMP Assumption. The 2019 WMP assumed the project site would develop as a combination of residential and non-residential land use types; the demand calculations for the project site based on the 2019 WMP assumptions are summarized on Table 3. Using the updated 2019 WMP demand coefficients, the water demands are estimated at approximately 966,000 gpd for Puente del Monte and approximately 1,259,000 gpd for Vista Lucia. (Table 3).
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Updated Gross Project Water Demands Based on Conceptual Land Use. The updated project water demands are based on the development information provided by EMC Planning Group staff. Using the updated 2019 WMP demand coefficients, the water demands for the conceptual land use plans are estimated at 1,065,000 gpd for Puente del Monte and 1,306,000 gpd for Vista Lucia (Table 3).
Comparison of Gross Demands between 2019 WMP and Conceptual Land Use. As summarized on Table 3, the development identified in the conceptual land use plans increase the projected water demand from the 2019 WMP by approximately 111 AFY for Puente del Monte and 53 AFY for Vista Lucia.
5.2 Comparison of Gross Project Water Demands with Potential Agricultural Use
The existing land use consists of various agricultural types, such as prime farmland, as shown on Figure 3. The following methodologies were used to estimate the average annual agricultural demand for the planned development areas.
Vista Lucia: According to crop data provided to the City by the project applicant, the existing agricultural lands generally consist of row crops. Historical groundwater production records for the existing uses within the planned development area were provided to the City by the project applicant. These records, for the years 2017-2019, document an average annual water use between 1,600 AFY and 2,000 AFY, with a period average of 1,830 AFY. Dividing this total water use volume by the planned development area of 768 acres results in an average annual agricultural use coefficient of 2.4 AFY/acre. Puente del Monte: According to information provided to the City by the project applicant , an existing land owner responsible for 427 acres of the 585 acres within the planned development boundary estimated existing agricultural water use at 1.0 AFY/acre. This average annual water use factor was used to estimate the average agricultural water use of 427 acres of the planned development area. According to other information provided by the project applicant the remaining 158 acres of land within the planned development boundary are row crops. For planning purposes the Vista Lucia row crop average annual agricultural use coefficient of 2.4 AFY/acre is used to estimate the average water demand of these 158 acres.
These average use factors were used to estimate the baseline agricultural demands for the lands within the planned development boundaries.
The comparison of the gross project water demands and the estimated existing agricultural water demands is summarized on Table 4. The existing agricultural lands within the boundaries of the Puente del Monte and Vista Lucia developments are 585 acres and 768 acres, respectively. Using the approximate agricultural water use coefficients as described above this results in an estimated December 2020 5 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
existing water use of 712,000 gpd and 1,613,000 gpd for Puente del Monte and Vista Lucia respectively.
The water demand for the conceptual land use plans is estimated at 1,065,000 gpd and 1,306,000 gpd for Puente del Monte and Vista Lucia respectively (Table 4). The gross estimated effect of the Vista Lucia development is a demand decrease of approximately 343 AFY. The gross estimated effect of the Puente del Monte development is a demand increase of approximately 396 AFY.
However, these demand estimates do not take into account water demand offsets related to recharge and wastewater percolation, which offset the impact of the demand on the groundwater basin. These water demand offsets are included in a more detailed net water demand analysis that is provided in the following sections.
5.3 Net Water Demand Analysis
The water demand comparisons described in the previous sections do not take into account water demand offsets, for either existing agricultural of conceptual land use, that would be percolated and recharged to groundwater. To account for these demand offsets, a net water demand analysis was prepared by Akel Engineering to document the overall impact of the development on the groundwater table. It should be noted that a similar approach has been completed and adopted for the City of Salinas. This analysis is summarized on Table 5 and includes the following demand offset volumes:
Agricultural Recharge: It was assumed that 30% of the applied agricultural irrigation water percolates as a form of groundwater recharge.
Project Outdoor Water Use Recharge: It was assumed that 20% of the water applied as outdoor irrigation percolates as a form of groundwater recharge. The outdoor water use total was estimated based on the ratio between water demand and sewer flow factors documented in the City of Gonzales 2019 Water Master Plan and Wastewater Master Plan.
Project Treated Wastewater Percolation: For conservative planning purposes, it was assumed that 90% of indoor water use will be percolated at the City of Gonzales WWTP following treatment. The indoor water use total was estimated based on the ratio between water demand and sewer flow factors documented in the City of Gonzales 2019 Water Master Plan and Wastewater Master Plan.
The results of the net water demand analysis are described in the following sections
5.3.1 Future Development Conditions – Puente del Monte
The existing net agricultural demand is 558 AFY, which accounts for potential groundwater recharge. The net development demand is 380 AFY, which accounts for outdoor water use recharge and treated wastewater percolation. This results in a net groundwater demand reduction December 2020 6 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
of approximately 178 AFY from existing agricultural conditions for the Puente del Monte development.
5.3.2 Future Development Conditions – Vista Lucia
The existing net agricultural demand is 1,265 AFY, which accounts for potential groundwater recharge. The net development demand is 482 AFY, which accounts for outdoor water use recharge and treated wastewater percolation. This results in a net groundwater demand reduction of approximately 783 AFY from existing agricultural conditions for the Puente del Monte development.
5.3.3 Future Development Conditions – Puente del Monte and Vista Lucia Under future development conditions, assuming the construction of both Puente del Monte and Vista Lucia, the total net demand is 862 AFY. The demand decrease due to the development of both Puente del Monte and Vista Lucia is approximately 961 AFY from existing agricultural conditions.
6.0 GROUNDWATER BASIN
The City is located above three subbasins of the Salinas Valley Groundwater Basin: the 180/400- Foot groundwater subbasin, the Eastside Subbasin, and the Forebay Subbarea. As shown on Figure 4, a majority of the existing City limits and the project site are within the 180/400-Foot and Eastside subbasins, with Highway 101 generally serving as the boundary between these two subbasins. The Salinas Valley Basin Groundwater Sustainability Agency (SVBGSA) is in the process of preparing groundwater sustainability plans for the multiple groundwater subbasins located within the Salinas Valley Basin, as well as a Valley-Wide Integrated Sustainability Plan (ISP). Information from draft and final version of the documents were in the preparation of this WSA.
According to the draft ISP, groundwater levels show a general decline in both the 180/400-Foot subbasin and the Eastside subbasin. However, the Eastside subbasin is noted as having steeper levels of decline due to the lack of seawater intrusion bolstering water volumes. The draft ISP also noted that the 180/400-Foot and Eastside subbasins have more pronounced and prolonged declines during multi-year droughts than other areas of the Salinas Valley Basin. This is likely indicative of less observed recharge in these basins during wet seasons.
The average annual loss of storage in the Eastside subbasin was estimated at 3,800 AFY between 1944 and 2017, which is attributed to declining groundwater levels. By comparison, the average annual loss of storage in the 180/400-foot subbasin was estimated at 11,700 AFY during the same period; however, the majority of this loss is due to seawater intrusion.
According to the City’s 2019 WMP, three groundwater wells serve as the domestic water source of supply (Table 6). Based on the locations of the existing groundwater wells, shown on Figure 5, December 2020 7 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
it is assumed that the City is supplied by both the 180/400-Foot subbasin and the Eastside subbasin.
7.0 WATER SUPPLY RELIABILITY
There are two aspects of supply reliability to be considered. The first relates to immediate service needs and is primarily a function of the availability and adequacy of the supply facilities. This aspect is considered for emergency reliability. The second aspect is climate-related, and involves the availability of water during mild or severe drought periods.
7.1 Groundwater Supply Facilities
The City currently uses local groundwater as its primary source of supply. Water supply for the municipal water system is extracted from underground aquifers via three existing groundwater wells located throughout the City (Table 6).
The City’s 2019 WMP recommends the construction of future groundwater wells to meet supply requirements as demand increases. The City’s storage facilities also enhance long-term reliability.
These facilities provide emergency storage sufficient to handle the service area needs during power outages or other emergencies. Adding supply and distribution system enhancements will also add reliability through redundancy.
7.2 Supply during Single Dry and Multiple Dry Years
The SVBGSA draft ISP describes historical levels within the Salinas Valley Groundwater Basin, which includes the 180/400-Foot and Eastside subbasins, as generally decreasing. Due to existing seawater intrusion in the 180/400-Foot subbasin, groundwater levels have historically decreased more gradually in this basin than in the Eastside subbasin. Additionally, the 180/400- Foot subbasin GSP indicates that available surface water supplies allow for a small reliable supply in excess of natural surface recharge within the subbasin during normal and wet years, which translates into carry over storage during single dry years. During multiple dry years, carry-over storage does not provide additional reliable supply; however, during the 2012-2015 historical drought, a significant increase in groundwater pumping was not observed even though no additional supplies were released to the subbasin during 2014 and 2015.
It should be noted that the SVBGSA intends to release the draft GSP for the Eastside Subbasin later this year. The vast majority of development proposed within the Puente del Monte and Vista Lucia developments will occur over top of the Eastside Subbasin. While recent reliability statistics are not currently available, anecdotal information suggests that the Eastside Subbasin is more susceptible to groundwater declines as noted above.
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Akel Engineering Group City of Gonzales
8.0 RECYCLED WATER
The City is planning on constructing a wastewater reclamation facility to serve select users within the Gonzales Agricultural Industrial Business Park. This facility would have an initial treatment capacity of 1.0 mgd, with potential for expansion up to 3.8 mgd. Recycled water supplies have the potential to offset groundwater pumping throughout the year and provide relief to the groundwater basins. For conservative planning purposes, this study assumes 1.0 mgd of recycled water as a form of potable demand offset on the groundwater pumping. This recycled water demand will offset the need to pump groundwater as a source of potable demand, and thus provide a sustainable benefit to the groundwater basin. This will include reducing peak pumping periods during the summer months, which are typically the most burdensome periods on the groundwater aquifer.
9.0 SUPPLY AND DEMAND COMPARISON
Groundwater supply budgets and availabilities were extracted, where available, from planning and engineering documents for the 180/400 Replace and the Eastside Subbasin. A brief summary of the available supply and demand comparison is as follows:
180/400-Foot Subbasin: The 180/400-Foot subbasin GSP estimates the projected sustainable yield for the subbasin, which is summarized on Table 7. The sustainable yield projections documented in the GSP show an estimated increase in pumping of approximately 27,000 AFY by the year 2030, for agricultural and urban pumping uses combined. The GSP notes that the current pumping trends will need to be reduced to meet the future sustainable yield.
Eastside Subbasin: The most recent groundwater budget information for the Eastside subbasin is provided in the 2004 Department of Water Resources Bulletin 118. This report estimates the groundwater supplies as 58,000 AFY (comprised of both natural surface recharge and subsurface inflow) and the total agricultural and urban extraction as 86,000 AFY, which results in a groundwater supply deficit of approximately 28,000 AFY (Table 8).
10.0 SUMMARY
The Puente del Monte and Vista Lucia developments in the City of Gonzales consist of developing approximately 585 acres and 770 acres of agricultural land use, respectively. According to the conceptual land use plans provided by EMC Planning Group staff this redevelopment will include residential, commercial, institutional, and open space land uses.
The water demands for these conceptual land use plans are as follows:
• Existing Demands – Agricultural Land Use. The estimation of existing agricultural water use is summarized on the following page.
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o Puente del Monte – Crop information for the existing agricultural lands within the planned development areas was provided to the City by the project applicant. An average agricultural water use factor of 1.0 AFY/acre was applied to 427 acres of the project site while a factor of 2.4 AFY/acre was applied to the remaining 158 acres, resulting in an average agricultural water use of 797 AFY. o Vista Lucia – Crop information for the existing agricultural lands within the planned development areas was provided to the City by the project applicant. An average agricultural water use factor of 2.4 AFY/acre was applied to the 768 acre site for an average agricultural water use of 1,807 AFY.
Updated Project Water Demands Based on Proposed Land Use. The updated project water demands are based on the conceptual land use information provided by EMC Planning Group staff. Using the 2019 WMP demand coefficients, the demands for Puente del Monte and Vista Lucia are 1,193 AFY and 1,463 AFY, respectively. Net Water Demand Analysis. The results of the net water demand analysis are summarized as follows:
o Puente del Monte: Based on a net agricultural demand of 558 AFY and a net project water demand of 380 AFY, the Puente del Monte development results in a net groundwater pumping decrease of 178 AFY.
o Vista Lucia: Based on a net agricultural demand of 1,265 AFY and a net project water demand of 482 AFY, the Puente del Monte development results in a net groundwater pumping decrease of 783 AFY.
o Combined Development: Based on a combined net agricultural demand of 1,823 AFY and a total net project water demand of 862 AFY, the combination of both the Puente del Monte and Vista Lucia developments result in a net groundwater pumping decrease of 961 AFY.
December 2020 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonazles
PUENTE DEL MONTE AND VISTA LUCIA - WATER SUPPLY
ASSESSMENT
Figures
Gonzales
Johnson Canyon Rd
Gonzales River Rd
£¤101
S Alta St
10th St
Alta St
Gloria Rd
Iverson Rd
Legend PRELIMINARY
Vista Lucia Development
Puente Del Monte Development
Sphere of Influence
City Limits
Streets
Update: March 31, 2020
File Path: P:\xGIS\GIS_Projects\Gonzales\200331-WSA\GON_Fig1_ProjectLocation_072220.mxd 0 2,000 4,000 1,000
Feet5
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Puente Del Monte
and Vista Lucia WSA
City of Gonzales
Figure 1
Location Map
Gonzales
Johnson Canyon Rd
Gonzales River Rd
£¤101
S Alta St
10th St
Alta St
Gloria Rd
Iverson Rd
PRELIMINARY Legend
General Plan Land Use
Low Density Residential
Medium Density Residential
Medium-High Density Residential
High Density Residential
Highway Commercial
Mixed Use
Light Industrial
Parks and Open Space
Public Facilities
Sphere of Influence
City Limits
Streets
Update: December 14, 2020
File Path: P:\xGIS\GIS_Projects\Gonzales\200331-WSA\GON_Fig2_ProjectLU_121420.mxd 0 2,000 4,000 1,000
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Figure 2
Conceptual Land
Use Plans
Puente Del Monte
and Vista Lucia WSA
City of Gonzales
Gonzales
Johnson Canyon Rd
Gonzales River Rd
£¤101
S Alta St
10th St
Alta St
Gloria Rd
Iverson Rd
PRELIMINARY Legend
FMMP 2016 Land Designations
Urban Built-Up Land
Grazing Land
Prime Farmland
Farmland of Statewide Importance
Unique Farmland
Other Land
Sphere of Influence
City Limits
Streets
Update: March 31, 2020
File Path: P:\xGIS\GIS_Projects\Gonzales\200331-WSA\GON_Fig3_ProjectLU_072220.mxd 0 2,000 4,000 1,000
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Figure 3
Agricultural Lands
Puente Del Monte
and Vista Lucia WSA
City of Gonzales
Data Source: State of California Department of Conservation Division of Land Resource Protection/Farmland Mapping & Monitoring Program (FMMP) !(
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Monterey
Bay
Pacific
Ocean
Salinas River
Gonzales
Marina Salinas
Seaside
Monterey
Greenfield
King City Los Padres
National Forest
Pinnacles
National Park
!(
Carme l River
San Benito River
·|}þ1
£¤101
·|}þ1
UV68
UV183
£¤101
East Side
Aquifer
180/400 Foot
Aquifer
Corral De Tierra
Area
Seaside
Area
Forebay
Aquifer
Upper Valley
Aquifer Arroyo Se co River
San Juan Bautista
Area
Carmel
Valley
UV146
UV25
San Benito
River Valley
Bitter Water
Valley
Tres Pinos
Valley
Pacific Cove
Soledad
Sources: Esri, USGS, NOAA
Legend PRELIMINARY
DWR Groundwater Basins
Salinas Valley Basin with Subbasins
Protected Open Space
Urbanized Areas
File Path: P:\xGIS\GIS_Projects\Gonzales\200331-WSA\GON_Fig4_GroundWaterBasins_033120.mxd Update: March 31, 2020 024 1
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Figure 4
Groundwater Basins
Puente Del Monte
and Vista Lucia WSA
City of Gonzales
#*
#*
#*
#*
#*
Gonzales
Johnson Canyon Rd
Gonzales River Rd
£¤101
S Alta St
10th St
Alta St
Gloria Rd
Iverson Rd
Forebay Aquifer
East Side Aquifer
180/400 foot Aquifer
180/400 foot
Aquifer
East Side Aquifer
Well 5
Well 6
Well 4
Well 3
(Decommissioned)
Well 2
Legend PRELIMINARY
#* Active Groundwater Wells
#* Inactive Groundwater Wells
Streets
Vista Lucia Development
Puente Del Monte Development
City Limits
Groundwater Subbasins
Update: April 13, 2020
File Path: P:\xGIS\GIS_Projects\Gonzales\200331-WSA\GON_Fig5_GroundwaterWells_041320.mxd 0 2,000 4,000 1,000
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Figure 5
Existing Groundwater
Wells
Puente Del Monte
and Vista Lucia WSA
City of Gonzales
December 2020 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonzales
PUENTE DEL MONTE AND VISTA LUCIA- WATER SUPPLY
ASSESSMENT
Tables
Table 1 Conceptual Land Use Plan Inventory
Water Supply Assessment
City of Gonzales
PRELIMINARY
(acres) (acres) (du) (acres) (du)
Residential Uses
Low Density Residential 139 596 242 1,210
Medium Density Residential 85 619 161 1,127
Medium‐High Density Residential 73 794 45 540
High Density Residential 19 569 22 528
Subtotal 316 2,578 470 3,405
Non‐Residential Uses
Mixed Use 6.1 45.0 8.0 93.0
Commercial 38.3 0.0 0.0 0.0
Light Industrial 21.1 0.0 0.0 0.0
Parks3 54.3 0.0 73.0 0.0
Institution/School 20.0 0.0 42.0 0.0
Subtotal 139.8 45.0 123.0 93.0
Non‐Demand Generating
Detention, Drainage, buffers, other Open Space 63.4 0.0 73.0 ‐ Roads 66.0 0.0 102.0 ‐
Agricultural 1,353 0.0 0.0 0.0
Subtotal 129.4 0.0 175.0 ‐
Total
585.3 2,623 768.0 3,498
Notes:
11/5/2020
1. Source: Puente Del Monte Land Use Plan Stats received from EMC Planning Group October 6, 2020.
2. Source: Vista Lucia Project Description received from EMC Planning Group February 25,2020.
3. Vista Lucia parks included following: Neighborhood Park, Community Park, Promenades, and Village Green.
Future Land Use
Puente Del Monte1 Vista Lucia2 Land Use Type Existing Land Use Table 2 Development Comparison
Water Supply Assessment
City of Gonzales
PRELIMINARY
Development Comparison
Puente Del Monte Vista Lucia
2019 Water
Master Plan1
Conceptual Land
Use Plan
2019 Water
Master Plan1
Conceptual Land
Use Plan
Residential Uses (Dwelling Units)
Low Density Residential 341 596 1,054 1,210
Medium Density Residential 1,195 619 1,272 1,127
Medium‐High Density Residential 596 794 605 540
High Density Residential 448 569 566 528
Total ‐ Residential Uses 2,580 2,578 3,497 3,405
Other Uses (Acres)
Mixed Use 5.9 6.1 0.0 8.0
Commercial 0.0 38.3 5.9 0.0
Light Industrial 21.1 21.1 0.0 0.0
Parks 51.5 54.3 61.0 73.0
Institution/School 0.0 20.0 0.0 42.0
Total ‐ Non‐Residential Uses 78.5 139.8 66.9 123.0
Notes:
11/5/2020
1. Source: City of Gonzales 2019 Existing City Plus Sphere of Influence Water Master Plan.
Land Use Type
Table 3 Comparison of Gross Project Water Demands with 2019 Water Master Plan Water Supply Assessment
City of Gonzales
PRELIMINARY
Land Use Inventory
Residential Uses Other Uses
Low Density Residential
Medium Density
Residential
Medium‐High Density
Residential
High Density Residential
Mixed Use
Commercial
Light Industrial
Parks
Institution/School
Total
(DU) (DU) (DU) (DU) (acres) (acres) (acres) (acres) (acres) Baseline Gross Water Demands ‐ 2019 Water Master Plan
Residential Dwelling Units and Non‐Residential Area
Puente del Monte 341 1,195 596 448 5.9 0.0 21.1 51.5 0.0 Vista Lucia 1,054 1,272 605 566 0.0 5.9 0.0 61.0 0.0
Average Annual Water
Demand Coefficients1 gpd/unit 352 352 352 352 1,800 1,700 1,500 300 1,700 Puente del Monte gpd 120,032 420,640 209,792 157,696 10,620 0 31,650 15,450 0 965,880 Vista Lucia gpd 371,008 447,744 212,960 199,232 0 10,030 0 18,300 0 1,259,274 Total gpd 491,040 868,384 422,752 356,928 10,620 10,030 31,650 33,750 0 2,225,154 Updated Gross Project Water Demands Based on Conceptual Land Use Residential Dwelling Units and Non‐Residential Area
Puente del Monte 596 619 794 569 6.1 38.3 21.1 54.3 20.0 Vista Lucia 1,210 1,127 540 528 8.0 0.0 0.0 73.0 42.0
Average Annual Water
Demand Coefficients1 gpd/units 352 352 352 352 1,800 1,700 1,500 300 1,700 Project Development Demands
Puente del Monte gpd 209,792 217,888 279,488 200,288 10,980 65,025 31,605 16,293 34,034 1,065,393 Vista Lucia gpd 425,920 396,704 190,080 185,856 14,400 0 0 21,900 71,400 1,306,260 Total gpd 635,712 614,592 469,568 386,144 25,380 65,025 31,605 38,193 105,434 2,371,653 Comparison of Gross Demands between 2019 WMP and Conceptual Land Use (negative values indicate decreases from 2019 WMP)
gpd 89,760 ‐202,752 69,696 42,592 360 65,025 ‐45 843 34,034 99,513 AFY 101 ‐227 78 48 0 73 0 1 38 111
gpd 54,912 ‐51,040 ‐22,880 ‐13,376 14,400 ‐10,030 0 3,600 71,400 46,986 AFY 62 ‐57 ‐26 ‐15 16 ‐11 0 4 80 53
11/5/2020
Notes:
1. Unless noted otherwise , demand coefficients based on City of Gonazles 2019 WMP. Residential demand coefficients adjusted based on 4.4 persons per household and 80 gallons per person per day.
Description Units
Baseline Development Water Demands
Puente del Monte
Vista Lucia
Table 4 Comparison of Gross Project Water Demands with Agricultural Water Demands Water Supply Assessment
City of Gonzales
PRELIMINARY
Land Use Inventory
Residential Uses Other Uses
Low Density Residential
Medium Density Residential
Medium‐High Density
Residential
High Density Residential
Mixed Use
Commercial
Light Industrial
Agricultural ‐ Vista Lucia
Parks
Institution/School
Total
(DU) (DU) (DU) (DU) (acres) (acres) (acres) (acres) (acres) (acres) Agricultural Water Demands ‐ Existing Land Use
Non‐Residential Area
Puente del Monte 0 0 0 0 0.0 0.0 0.0 427.0 158.0 0.0 0.0 0.0 Vista Lucia 0 0 0 0 0.0 0.0 0.0 0.0 0.0 768.0 0.0 0.0
Average Annual Water
Demand Coefficients2,3 gpd/unit 352 352 352 352 1,800 1,700 1,500 890 2,100 2,100 300 1,700 Puente del Monte gpd 0 00 0 0 0 0 0 0 0 711,830
Vista Lucia gpd 0 0 0 0 0 0 0 1,612,800 0 0 1,612,800
Total gpd 0 0 0 0 0 0 0 1,612,800 0 0 2,324,630
Updated Gross Project Water Demands Based on Conceptual Land Use Residential Development Units and Non‐Residential Area
Puente del Monte 596 619 794 569 6.1 38.3 21.1 0.0 0.0 0.0 54.3 20.0 Vista Lucia 1,210 1,127 540 528 8.0 0.0 0.0 0.0 0.0 0.0 73.0 42.0 Average Annual Water
Demand Coefficients1,2 gpd/units 352 352 352 352 1,800 1,700 1,500 890 2,100 2,100 300 1,700 Project Water Demands
Puente del Monte gpd 209,792 217,888 279,488 200,288 10,980 65,025 31,605 0 16,293 34,034 1,065,393 Vista Lucia gpd 425,920 396,704 190,080 185,856 14,400 0 0 0 21,900 71,400 1,306,260 Total gpd 635,712 614,592 469,568 386,144 25,380 65,025 31,605 0 38,193 105,434 2,371,653 Comparison of Gross Demands between Existing Land Use and Conceptual Land Use (negative values indicate decrease from existing land use) gpd 209,792 217,888 279,488 200,288 10,980 65,025 31,605 0 16,293 34,034 353,563 AFY 235 244 313 224 12 73 35 0 18 38 396
gpd 425,920 396,704 190,080 185,856 14,400 0 0 ‐1,612,800 21,900 71,400 ‐306,540 AFY 477 444 213 208 16 0 0 ‐1,807 25 80 ‐343
11/19/2020
Notes:
1. According to land use information provided by the project applicant to the City of Gonzales,427 acres of the project area consist of vineyards that use an average demand of 1.0 AFY/acre and the remaining 158 acres consists of row crops. For planning purposes the average demand coefficient for the 158 acres of row crops was assumed equal to the Vista Lucia ag use, which also consists of row crops.
2. Unless noted otherwise , demand coefficients based on City of Gonazles 2019 WMP. Residential demand coefficients adjusted based on 4.4 persons per household and 80 gallons per day per person.
3. Agricultural demand coefficients based on historical groundwater production records and other consumption information for existing agricultural lands within the planned development boundaries. Agricultural ‐ Puente del Monte1 ‐711,830
0 0
0 (acres)
Agricultural Water Demands
Vista Lucia
Puente del Monte
Description Units
711,830
0 711,830
0 0
‐797
Table 5 Net Water Demand Analysis
Water Supply AssessmentCity of Gonzales
PRELIMINARY
Development Condition
Puente del Monte Vista Lucia Puente del Monte + Vista Lucia (afy) (afy) (afy)
Existing Agricultural Demands
Agricultural Demand1 797 1,807 2,604
Potential Recharge2 239 542 781Net Agricultural Demand
(Agricultural Demand ‐ Recharge Potential)
Project Water Demands
Project Water Demands3 1,193 1,463 2,657
Demand Offsets
Outdoor Water Use Recharge4,5 75 96 170
Treated Wastewater Percolation6,7 739 886 1,625
Net Development Demand
(Project Water Demands ‐ Demand Offsets)
Demand Comparison
Demand Decrease
(Existing Net Agricultural ‐ Total Net Demand )
11/18/2020
Notes:
1. Existing agricultural demands based on total area within planned development boundaries and assume an average annual water use factor estimated from historical production records and other consumption data provided to City staff by the project applicants.
2. Assumes 30% of agricultural demands will percolate, acting as groundwater recharge.
3. Project demands based on conceptual land use plans and water demand factors generally consistent with the City 2019 Water Master Plan.
4. Outdoor Water Use Recharge = 20% x Outdoor Water Use, where outdoor water use estimated based on ratio between land use demand and flow factors documented in the City 2019 Water Master Plan and Wastewater Master Plan.
5. Assumes 20% of outdoor water use will percolate, acting as groundwater recharge.
6. Treated Wastewater Recharge = 90% x Indoor Water Use, where indoor water use estimated based on ratio between land use demand and flow factors documented in the City 2019 Water Master Plan and Wastewater Master Plan.
7. For conservative planning purposes, 90% of indoor water use is assumed to be percolated at the WWTP. 1,265
Demands and Offsets
178 783 961
380 482 862
558 1,823
Table 6 Existing Water Supply Facilities
Water Supply Assessment
City of Gonzales
PRELIMINARY
Well No.
Current Production
Capacity1
(gpm) (afy)
4 1,500' SE of the intersection of S Alta St
and C St 1,200 1,932
5 Intersection of Fanoe Rd and Barbera Way 1,200 1,932
6 500' SW of the intersection of Alta St and
Katherine St 1,800 2,898
Total 4,200 6,762
Notes:
4/9/2020
1. Source: City of Gonzales 2019 Water Master Plan.
Location
Table 7 180/400‐Foot Subbasin Sustainable Yield
Water Supply Assessment
City of Gonzales
PRELIMINARY
Year
Demand Condition Historical 2030 2070
(AFY) (AFY) (AFY)
Annual Groundwater Pumping
Agricultural 89,000 94,800 99,500
Urban 18,900 20,500 21,000
Total 107,900 135,800 141,600
Sustainable Yield2
Net Pumping 108,100 115,300 120,600
Seawater Intrusion ‐10,599 ‐3,500 ‐3,900
Change in Storage ‐400 ‐4,600 ‐4,700
Projected Sustainable Yield 97,200 107,200 112,000
Percent Pumping Reduction 10.0% 7.0% 7.1%
Puente del Monte Impact to Groundwater
Net Pumping with Development
without Recycled Water 108,496 115,696 120,996
with Recycled Water3 106,980 114,180 119,479
Percent Pumping Reduction
without Recycled Water 10.4% 7.3% 7.4%
with Recycled Water3 9.1% 6.1% 6.3%
Vista Lucia Impact to Groundwater
Net Pumping with Development
without Recycled Water 107,757 114,957 120,257
with Recycled Water3 106,980 114,180 119,480
Percent Pumping Reduction
without Recycled Water 9.8% 6.7% 6.9%
with Recycled Water3 9.1% 6.1% 6.3%
Notes:
11/16/2020
1 Source: 180‐400 Foot Subbasin Groundwater Sustainability Plan, Table 6‐12 (Historical) and Table 6‐30 (2030, 2070)
2. Source: 180‐400 Foot Subbasin Groundwater Sustainability Plan, Table 6‐31
3. Recycled water volumes equal to 1.0 mgd, based on planned treatment capacity of the City of Gonzales Industrial Wastewater Treatment Facility.
Table 8 Eastside Subbasin Groundwater Budget
Water Supply Assessment
City of Gonzales
PRELIMINARY
Demand Condition
(Without Recycled
Water)
(With Recycled
Water2
)
(Without Recycled
Water)
(With Recycled
Water2)
(AFY) (AFY) (AFY) (AFY) (AFY)
Natural Recharge 41,000 41,000 41,000 41,000 41,000
Subsurface Inflow 17,000 17,000 17,000 17,000 17,000
Agricultural/Urban Extraction 86,000 86,396 85,276 85,657 84,537 Groundwater Balance ‐28,000 ‐28,396 ‐27,276 ‐27,657 ‐26,537 Notes:
11/16/2020
1. Source: 2004 DWR Bulletin 118 for Eastside Groundwater Subbasin
2. Recycled water volumes equal to 1.0 mgd, based on planned treatment capacity of the City of Gonzales Industrial Wastewater Treatment Facility.
Existing
Conditions1
With Puente del Monte With Vista Lucia
December 2020 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonzales
PUENTE DEL MONTE AND VISTA LUCIA - WATER SUPPLY
ASSESSMENT
Appendices
December 2020 Puente del Monte and Vista Lucia WSA
Akel Engineering Group City of Gonzales
City of Gonzales
PUENTE DEL MONTE AND VISTA LUCIA - WATER SUPPLY
ASSESSMENT
Appendix A – Conceptual Land Use
Planning Information
(Provided by EMC Planning Group)
Table Error! No text of specified style in document.‐1 Projected Puente del Monte Development Capacity
Land Use Type Acres1 Dwelling Units Residential
Density2
Building Square
Footage3
Residential Uses
Low Density Residential 139.27 596 4.28 n/a
Medium Density Residential 84.64 619 7.31 n/a
Mixed Use4 - 45 7.37 n/a
Medium-High Density Residential 73.04 794 10.87 n/a
High Density Residential 19.17 569 29.68 n/a
Residential Uses Subtotal 316.12 2,623
Non-Residential Uses
Highway Commercial5 38.25 n/a 270,753
Light Industrial 21.07 n/a 149,144
Parks and Open Space6 117.72 n/a 0
Public Facilities (Schools) 20.02 n/a -7
Master Circulation 66.02 n/a 0
Mixed Use 6.11 n/a 43,249
Non-Residential Uses Subtotal 269.19 n/a 463,146
Project Total 585.31 2,623 463,146
SOURCE: Jackson Family Investments 2020
NOTES:
1. Acreage is approximate.
2. Density calculated as residential units per gross acre.
3. Non-residential building capacity is derived by multiplying acres x 43,560 square feet/acre x .65 x a floor to area ratio .25. The .65 factor is a generally accepted land efficiency factor which reflects reduced buildable area potential due to land demand from infrastructure, roads, physical constraints, and other variables.
4. Acreage for Mixed Use is included under Non-Residential Uses.
5. Highway Commercial parcels (identified as W-01 and W-02 on conceptual land use plan) are within the existing city limits and not part of the annexation area.
6. Parks and Open Space acreage includes Community Parks (42.84 acres), Neighborhood Parks (3.16 acres), Pocket Parks (8.31 acres), and Agricultural Buffers (63.41 acres).
7. Building square footage for schools is not included – the Gonzales Unified School District would design and construct the schools based on need, and assess school capacity/building requirements.
Table 2.1: Land Use Summary
Land Use Designation and Zoning District Approximate Gross Acres1 Maximum Units (du/ac or s.f.) Village One Village Two Total
Residential UsesResidential (see Table 2.2 for Zoning Designations) 260 3 210 3 470 Up to 3.498 duCommercialNeighborhood Commercial / Mixed Use (VL‐NC/MU) 2 6 8 Up to 120,000 sf 2Other Land Uses Neighborhood Parks 12 10 22Community Park 14 15 29Promenades 13 7 20Village Green 1 1 2Detention, Drainage, buffers, other Open Space 30 43 73 Parks and Open Space Subtotal (VL‐P/QP) 70 76 146Elementary School (VL‐P/QP) 12 12 24Middle School (VL‐P/QP) 18 18Major Roads & Other Miscellaneous Areas 66 36 102Land Use Totals 410 358 768 Up to 3,498 dwelling units Up to 120,000 square feet Commercial
Notes:
1. Approximate gross acres includes all land (including interior local streets and rights‐of‐way) designated for a particular land usel category.
2. Commercial square footage allowances are based on a maximum .36 Floor Area Ratio factor. This factor does not include mixed use residential units.
3. Acreage does not include Mixed Use residential component, to avoid double‐counting Mixed‐Use acreages for commercial component.
Table 2.2: Residential Land Use Summary
Residential Land Use and Zoning District Gross Acres 1
Allowable Gross Density
Range by Residential
Category (du/ac) 4
Target
Dwelling Units 2
Total
Target
Units
Percentage
of Total
Units3
Village
One
Village
Two
Village
One
Village
Two
Neighborhood Residential Low (VL‐NRL) 137 105 3‐6 (5 du/ac target) 690 520 1,210 35.0 %Neighborhood Residential Medium (VL‐NRM) 92 69 6‐9 (7 du/ac target) 644 483 1,127 32.0 %Neighborhood Residential Medium‐High (VL‐NRMH) 20 25 9‐15 (12 du/ac target) 240 300 540 15.5 % Neighborhood Residential High (VL‐NRH) 11 11 15‐24 (24.5 du/ac target) 264 264 528 15.0 % Neighborhood Commercial /Mixed Use5 (VL‐NC/MU) 25 65 10‐125 (11.8 du/ac target) 23 70 93 2.5 % Sub‐Totals by Village 260 210 1,861 1,637Overall Totals: Villages One and Two 470 7.4 average du/ac. 3,498 100 % Notes:
1. Gross acres include all land parcels (including interior local streets and rights‐of‐way) designated for a particular residential category. According to City standards, the density of dwelling units per gross residential acre “is calculated exclusive of schools, parks, drainages, commercial areas, and major rights‐of‐way.”
2. Unit counts within each residential land use category or parcel may vary, as long as the City requirement of a 7.0 du/ac. overall minimum density is met for the overall project, and the overall unit count shown above is not exceeded.
3. Unit counts must conform to General Plan requirements for minimum percentage of units by density category.
4. Allowable gross density ranges for parcels within each category are taken from City’s 2008 “Neighborhood Design Guidelines and Standards” for the New Growth Area.
5. Mixed Use residential units may be either “horizontal” (uses in separate buildings) or “vertical” (uses in the same building). The residential component of this mixed use area allows for up to 12 du/ac. within mixed use sites. (Note: Acreages of this land use are not included in total acreage, to avoid double‐counting the retail commercial component in Table 2‐1 above