1

County Planning Department contracted the RCD to design a water use offset program for agriculture users in Paso Basin.
• developed in response to the urgency ordinance which requires NEW irrigated Ag to offset their total projected water use
. 2

SLO
1. Reason for ordinance: Severe
Decline
2. What is considered “new irrigated Ag?” *
• Crop conversions
• Increased crop density
• New installations on previously un-irrigated lands
*Per urgency ordinance language
3

• RCD assembled a multidisciplinary project team
• Hydrogeologist
• Hydrologic engineer
• UC Cooperative Extension staff
• Cal Poly ITRC department faculty
• NRCS Conservationist
• GIS specialist
• Agricultural manager
• Biological Expertise
• Analysis of potential for offset credits within regional areas
• GIS mapping and verification of crop layer data
• Data and methodology review of water use by crop type
• Master Water Report
• UC Extension input
4

• Crop Conversions
• New irrigated acreage
• Increased crop density
• Rootstock conversions
• Rural groundwater uses not included in domestic program
5

Crop Conversion
Project Type
New Irrigation Ag
Crop Conversion
Type of Credit
Fallowed Land/Create Credit
Same Property
Offset Location
Adjacent or Different Property
6

Determine amount of Water Credit
(current crop acreage x water use factor)
Determine Potential Acres of New Crop
(water credit amount / water use factor)
Same
Property,
Same Well
Same
Property,
Different
Well
Contiguous
Parcel
Noncontiguous
Parcel
7

Master Water Report http://www.slocountywater.org
8

Table 1. Crop Group and Commodities Used for the Agricultural Demand Analysis
Alfalfa
Nursery
Crop Group
Pasture
Small Grains
Citrus
Deciduous
Strawberries
Vegetables
Vineyard
Primary Commodities
Alfalfa
Christmas trees, miscellaneous nursery plants, flowers
Miscellaneous grasses, mixed pastures, sod/turf, sudangrass
Oats, barley, wheat
Avocados, grapefruits, lemons, oranges, olives, kiwis, pomegranates (nondeciduous)
Apples, apricots, berries, peaches, nectarines, plums, figs, pistachios, persimmons, pears, quinces, strawberries
Strawberries
Artichokes, beans, miscellaneous vegetables, mushrooms, onions, peas, peppers, tomatoes
Wine grapes, table grapes
9

Annual Crop Specific Applied Water
(AF/Ac/Yr)=
ETc − ER
1 − LR 𝑥 IE
+ FP where:
ETc = crop evapotranspiration = ETo x Kc
ETo = reference evapotranspiration
Kc = crop coefficient
ER = effective rainfall
FP = frost protection
LR = leaching requirement
IE = irrigation efficiency
10

Table 2. Existing Crop-Specific Applied Water (AF/Ac/Yr) by Crop for the Salinas/Estrella
WPA
Crop Group
Alfalfa
Citrus
Applied Water
(AF/Ac/Yr)
4.5
2.3
Deciduous
Strawberries
Nursery
Pasture
3.5
2.3*
2.5
4.8
Small Grain
Vegetables
1.7*
1.9
Vineyard 1.7
*Information obtained from Current Cost and
Return Studies, UCCE, UC Davis (Small grains
2013 data, Strawberries 2011 data)
11

Determine amount of Water Credit
(current crop acreage x water use factor)
Determine Potential Acres of New Crop
(water credit amount / water use factor)
Same
Property,
Same Well
Same
Property,
Different
Well
Contiguous
Parcel
Noncontiguous
Parcel
12

Same Property,
Same Well
Same Property,
Different Well
Contiguous
Parcel
Non-contiguous
Parcel
Proximity Analysis
Meets
Standard
Neighboring Well Impact analysis
Meets
Standard
Deed Restriction Recorded & Well Meter Installed
Annual Verification (3rd Party reporting)
13

Neighboring Well Criteria
• Applicant must identify one domestic and one ag well adjacent to property
• Increased pumping cannot significantly impact neighboring irrigation and domestic wells
• Domestic wells – 15 feet additional drawdown
• Irrigation wells – 30 feet additional drawdown
• Simple calculator is used to compute water level drawdown at various distances
• Notice sent to well owners so well-specific information can be considered
14

•
Must define acceptable distance where credit will likely offset the impact
•
Simple Calculator is used to determine this distance
•
Must be similar water bearing zone and depth 15

16

Same Property,
Same Well
Same Property,
Different Well
Contiguous
Parcel
Non-contiguous
Parcel
Proximity Analysis
Meets
Standard
Neighboring Well Impact analysis
Meets
Standard
Deed Restriction Recorded & Well Meter Installed
Annual Verification (3rd Party reporting)
17

Decline Map Sample – Paso Basin
Credit cannot be used to increase pumping within severe groundwater level decline area as defined by SLO County
• Proposed 50’ water decline level
• Reviewed annually
• Annual map of decline published
18

RCD collaborating with local stakeholders
• Paso Robles Wine Alliance
• Ag Liaison Committee
• Farm Bureau
• Cattlemans Association
• Vineyard Team
• Olive Growers Association
• Pro Water Equity
• Town Hall meetings
19

• Groundwater basin(s) are natural features that change over time and the program is designed with flexibility and adaptation in mind.
• Issue is complex in nature, and program tries to encompass multiple layers of operational complexity.
• Program designed to be flexibly tiered, simplified, and user-friendly.
20

Contact Email
Devin Best, Executive Director devin@us-ltrcd.org
Jeff Barry, Hydrogeologist
Ben Burgoa, Ag Engineer
JBarry@gsiws.com
Ben.Burgoa@rcdmonterey.org
Kelly Gleason, Policy Specialist kelly@us-ltrcd.org
Laura Edwards, Program
Director laura@us-ltrcd.org
21