[INSERT NAME] Valley
Alternate Monitoring of DWR Basin [BASIN #]
[INSERT BASIN-SPECIFIC COVER GRAPHIC]
Prepared By
Mojave Water Agency
[DATE (Month Year)]
[INSERT TOC]
Executive Summary
Assembly Bill 1152 (Water Code Section 10931(b)) allows for Alternate Monitoring of groundwater basins if any one of the following conditions is met:
· Groundwater levels are unaffected by land use activities or high TDS
· Land ownership prohibits access
· Inaccessible due to geologic or geographic features
[INSERT SPECIFIC BASIN NAME AND NUMBER] The Means Valley Groundwater Basin (Basin 7-17) qualifies for Alternate Monitoring in the CASGEM Program as detailed in Water Code section 10932 (b) because water levels are materially unaffected by land use; however, water levels appear to be locally affected by groundwater extractions and Alternate Monitoring status for the Basin will have to be closely considered in the future. Land use in the valley consists of sparse residential with no significant outside irrigation, no significant agriculture, and no industry. The population of the 23.4 square mile valley is 62 people as of the 2010 Census. This amounts to 2.6 people per square mile (down 13% from 71 in 2000). Total consumptive water use in the Basin is estimated at 32 acre feet per year, which is less than the average annual natural recharge for the Basin estimated by DWR (2003) at 100 acre feet per year. Unless land use changes significantly, land use is not likely to have a material impact groundwater levels in the foreseeable future.…or…Total consumptive water use for the Basin is estimated at 0 (zero) acre feet per year.
Alternate techniques employed in monitoring this Basin consist of reviewing/analyzing the following:
· Aerial photography
· Census data
· Parcel data
· Well permits, well logs, & EIRs
· Water use
· Groundwater level data [Delete if not applicable]
Alternate Monitoring of the Basin will continue on an ongoing basis.
Introduction
On November 6, 2009, the California Water Code was amended with SBX7 6 by the State Legislature. SBX7 6 mandates a statewide groundwater elevation monitoring program to track seasonal and long-term trends in groundwater elevations. This program requires collaboration between the Department of Water Resources (DWR) and local monitoring entities to collect groundwater elevation data. In response to SBX7 6, DWR has developed the California Statewide Groundwater Elevation Monitoring (CASGEM) Program to “establish a permanent, locally-managed program of regular and systematic monitoring in all of California's alluvial groundwater basins” (CASGEM, 2011).
California Senate Bill SBX7 6 was amended on September 7, 2011 by AB 1152. AB 1152 states that under certain conditions basin monitoring can be carried out using alternate methods. Alternate monitoring of a basin makes exception for physical groundwater level measuring from monitoring wells. The California Department of Water Resources must approve Alternate Monitoring Status for a basin every 3 years (CASGEM, 2011).
Basin Description (DWR, 2003)
[INSERT BULLITIN 118 BASIN DESCRIPTION - …INCLUDING A REFERENCE TO “FIGURE 1”]
[INSERT BASIN-SPECIFIC WATER BUDGET DISCUSSION IF APPROPRIATE]
MWA/CASGEM Coverage (Basin Portion)
[DISCUSS JUSTIFICATION FOR BASIN SHAPEFILE]
MWA has volunteered to monitor the Means Valley Groundwater Basin as it lies entirely within MWA Service Area Boundaries (Figures 1 and 2).
Or…
MWA has volunteered to monitor the portions of Bessemer Valley Groundwater Basin that lie within MWA boundaries. This includes the west and south portions of the Basin and excludes the northeast section of the Basin as shown in figures 1 and 2. This report and the following discussion only takes into account the portions of the Basin that fall within MWA boundaries.
Land Use
Historic
[INSERT BASIN-SPECIFIC DETAILS FROM DWR, NWIS, & OTHER RECORD AS APPROPRIATE]
Current
[INSERT BASIN-SPECIFIC DETAILS AS APPROPRIATE]
Alternate Monitoring Qualifications
SBX7 6, which mandates state-wide groundwater level monitoring, was amended on September 7, 2011 by AB 1152 to allow, under certain conditions, for “Alternate Monitoring” of select basins. AB 1152 makes exception for the requirement to physically measure groundwater levels from monitoring wells for qualifying basins. The Alternate Monitoring criteria of AB 1152 are included below.
Water Code Section 10932(b) (CASGEM, 2011)
For purposes of reporting groundwater elevations pursuant to this part, and subject to subdivision (c), a monitoring entity may use alternate monitoring techniques for a basin or subbasin, instead of monitoring groundwater elevations directly through monitoring wells, if the basin or subbasin meets any of the following conditions:
(1) Land use or TDS
Groundwater elevations are unaffected by land use activities or planned land use activities, or naturally occurring total dissolved solids within the groundwater preclude the use of that water.
(2) Land ownership
It is underlying land that is wholly owned or controlled, individually or collectively, by state, tribal, or federal authorities, and groundwater monitoring information is not available or was requested from, but not provided by, the state, tribal, or federal authorities.
(3) Inaccessible
It is underlying an area where geographic or geologic features make monitoring impracticable, including, but not limited to, a basin or subbasin that is inaccessible to well-drilling equipment.
Basin Qualifications for Alternate Monitoring
[INSERT BASIN NAME] Groundwater Basin qualifies for Alternate Monitoring as detailed in Table 1 and discussed below. Basins that qualify for Alternate Monitoring shall be reevaluated on an ongoing basis and this report will be updated every three (3) years as established in AB 1152. MWA will use the following techniques to satisfy the requirements for Alternate Monitoring as outlined in AB 1152.
Alternate Monitoring
Aerial photography
Current aerial photography was surveyed to visually inspect for any activities within the Basin that may use groundwater. These include agricultural, industrial, homestead, or other development. Up to date aerial photography is available from the Farm Service Agency (FSA) of the United States Department of Agriculture. This agency acquires aerial imagery through the National Agriculture Imagery Program (NAIP) every three (3) years. Figure 2 shows the most current (INSERT YEAR) aerial photography of the Basin (FSA, 2012; Google Earth, 2012).
[INSERT BASIN-SPECIFIC DETAILS FROM AERIAL SURVEY – BOLD]
Census data
Census data was analyzed to track population density within the Basin. Since water use generally has a positive correlation with population density, a smaller population can be expected to use less water than a larger population. The most current data from the U.S. Census Bureau was used in this analysis. Figure 3 shows current population density data for the Basin.
[INSERT BASIN-SPECIFIC DETAILS FROM CENSUS DATA REVIEW – BOLD & INCLUDE PEOPLE PER MI2]
Improved Value Parcel Data and Land Ownership
Parcel data was reviewed for improved value to track development within the Basin. Improved value (improvements with a value greater than $0) correlates directly to water use. Parcels that have significant improved value generally have water use associated with them. Current parcel data was obtained from San Bernardino County for use in this review. Figure 4 shows the most current improved value parcel data for the Basin (SBC, 2012). In addition to parcel data, land ownership was considered for Alternate Monitoring qualification. AB 1152 makes an Alternate Monitoring exception for land access restrictions on government controlled lands. Figure 5 shows the most current land ownership data for the Basin (SBC, 2012).
[INSERT BASIN-SPECIFIC DETAILS FROM PARCEL DATA REVIEW – BOLD]
Well Permits and EIRs
MWA receives copies of Well Permits issued by San Bernardino County and Well Completion Reports (WCRs) filed with DWR (DWR, 2012) on a regular basis. MWA is also a reviewing agency for large project Environmental Impact Reports (EIRs). Incoming Well Permits, WCRs, and EIRs are monitored and investigated on an ongoing and on demand basis to track development within the Basin.
[INSERT BASIN-SPECIFIC DETAILS (IF THERE ARE ANY) FROM WELL PERMITS – BOLD]
MWA will continue to routinely review Well Permits, WCRs and EIRs as they are made available.
Estimated Water Use
Assessments of water use interpreted from reviews of information such as aerial photography, population data, and land use data are estimated. For this evaluation, water use refers to residential scale (small scale) use and estimates are based on measurements from aerial photography, GIS analysis, and well established water use constants. Individual households were counted and region-specific indoor water use assumptions, as documented in Table 2, were applied. Established quantified average domestic water use estimates were applied to residential and small scale agriculture (MWA, 2010). Vegetated area was measured and appropriate irrigation rates were applied. Return flow estimates were also factored into the water use calculations. Assumed water users in the Basin were discussed in the sections titled “Aerial Photography” and “Census Data” in this report. Estimated water use from the assumed users in the Basin is summarized in Table 2.
[INSERT BASIN-SPECIFIC WATER USE SUMMARY – BOLD]
Groundwater Levels
The CASGEM Program requires groundwater level measurements be taken from wells at a frequency of semiannual or greater. Remote desert basins, such as the [INSERT BASIN NAME] Groundwater Basin, often have legacy (historic but not currently monitored) and/or sporadic (currently monitored at a frequency less than semiannual) groundwater level data. These data, while not sufficient to comply with the monitoring frequency requirements of the CASGEM Program, are still valuable. Data from these wells can be found on the USGS National Water Information System (NWIS; USGS, 2012) and will also be uploaded to the CASGEM System. Groundwater level data that is measured less then semiannually is categorized in CASGEM as “Voluntary.” Details of these wells are included in the MWA/CASGEM Monitoring Plan.
[CHECK TO BE SURE THAT THERE ARE ACTUALLY WELLS PRESENT IN THE BAISN, IF SO THEN INCLUDE AND EDIT THE BASIN-SPECIFIC GROUNDWATER LEVELS SUMMARY BELOW. IF NOT THEN DELETE THIS SECTION - BOLD]
Voluntary Well 04N04E36B01 is located within the Means Valley Groundwater Basin. An NWIS Hydrograph (USGS, 2012) for 04N04E36B01 is included in the Appendix. Water measurements starting in 1975 and the associated hydrograph for 04N04E36B01 are (also) available on NWIS. The trend of biennial water level measurements from 1980 to 2012 indicates a decline of approximately 2 feet at a rate of approximately 0.063 feet per year. Although water level measurements from 04N04E36B01 suggest a long-term, slow decline, the measurements likely represent a localized effect associated with irrigation practices at the nearby pistachio orchard, located approximately 2,365 feet to the northwest. The lack of significant water use from a basin-wide perspective suggests that groundwater levels in the Basin as a whole are stable. This is further substantiated by consumptive use estimates which are below the estimated average annual natural recharge for the Basin. Localized effects should be expected in areas of recharge or extraction; however, the data currently suggest relative overall groundwater level stability within the Means Valley Groundwater Basin.
Conclusion
The Means Valley Groundwater Basin is eligible for Alternate Monitoring in accordance with AB 1152 (California Water Code Section 10932(b)) under condition (1) groundwater elevations are unaffected by land use activities or planned land use activities, or naturally occurring total dissolved solids within the groundwater preclude the use of that water. As required by AB 1152, MWA has reviewed available data for the Means Valley Groundwater Basin, including historic and recent water level data, aerial photography, census data, parcel data, Well Permits, and WCRs.
· Aerial photography (FSA, 2012; Google Earth, 2012) was reviewed and found a single agricultural operation (10 acre pistachio orchard) and a sparse residential community in the southern end of the Means Valley Groundwater Basin.
· Census data (Census, 2012) reported 62 residents and 32 occupied dwelling units in the Means Valley Groundwater Basin.
· San Bernardino County parcel data (SBC, 2012) showed that 3.8% of the parcels in the Means Valley Groundwater Basin have an improved value. Water use is generally associated with improved parcel values.
· MWA has estimated water use for Means Valley Groundwater Basin at 32 AFY; less than the average annual natural recharge estimated for the Basin by DWR (1975) at 100 AFY.
· Water levels in Well 04N04E36B01 indicate a long-term slow decline of approximately 0.063 feet per year. This decline is likely a localize effect associated with irrigation practices at the nearby pistachio orchard, located approximately XX feet to the XX.
Overall, the data suggest that groundwater levels are largely unaffected by land use within the Basin and the estimated water use is less than the estimated average annual natural recharge for the Basin. MWA recommends maintaining the Means Valley Groundwater Basin under Alternate Monitoring status and MWA will continue to monitor the Basin on an ongoing basis for changes in land use and associated water use.
[DID YOU INSERT “MWA PORTION” OF THE BASIN AS APPROPRIATE?]
[MAKE SURE REPORT IS CONSISTENT: “THE ‘X’ VALLEY GROUNDWATER BASIN” AS APPROPRIATE]
Signature
______
[INSERT NAME]
[INSERT TITLE]
[INSERT STAMP(S)]
Tables
[UPDATE TABLE 1 WITH BASIN-SPECIFIC CONDITIONS]
Table 1. [INSERT BASIN NAME] Groundwater Basin Qualifications for Alternate Monitoring Under CASGEM in Accordance with AB 1152. (CASGEM, 2011)
Qualification / Applicable / Comments:(1) Land use or TDS
(2) Land ownership
(3) Inaccessible
[UPDATE TABLE 2 WITH BASIN-SPECIFIC ASSUMED WATER USERS – OPTIONAL TABLE BASED ON SECTION “ESTIMATED WATER USE”]
Table 2. Water uses found within [INSERT GROUNDWATER BASIN NAME AND NUMBER]. Homesteads and Industrial are listed by number; all others are measured in terms of acres (area). These values are multiplied by the use factor (MWA, 2010) less an assumed return flow component to obtain the total water use in AFY.
Development / Numberor Area (Ac) / Production Use Factor (ft) / Return Flow (%)* / Consumptive Use (AFY) / CommentsHomesteads / # / 0.204 / 90% / (Census, 2012)
Tree/Shrubs / 3.1 / 0% / (FSA, 2012; Google Earth, 2012)
Turf / 8.7 / 0% / (FSA, 2012; Google Earth, 2012)
Ponds / 6.7 / 0% / (FSA, 2012; Google Earth, 2012)
Industrial / Varies / - / (FSA, 2012; Google Earth, 2012)
Total Water Use:
*RETURN FLOW ESTIMATES ARE INTENTIONALLY LOW FOR CONSERVATIVE (HIGHER WATER USAGE) ESTIMATES. Generally, almost all water used for indoor domestic use is discharged as wastewater into a local septic tank or sanitary sewer (if available) and therefore 90% return flow for indoor water use was chosen for consumptive use estimation purposes. This conservative assumption that 90% of indoor water use is return flow is based on a comparison of per capita water quantity estimates for indoor water use and septic recharge. Indoor water use is estimated at 69.3 gallons per day (AWWA, 1999) and septic recharge in the Mojave region is estimated at 70 gallons per day (USGS, 1993 and 2003). Outdoor water use was assigned a 0% return flow yield to produce conservative estimates of consumptive use.