In order to determine the total number of irrigation users of groundwater in the San Simon Valley Sub-basin, the Department utilized United States Geological Survey (USGS) Landsat satellite imagery, Cochise County Assessor information (both ownership data and parcel boundaries), Arizona State Land Department agricultural lease information available on-line, imagery available on Google Earth™, and internet searches. For purposes of this analysis, the Department sought to identify individuals/entities who had irrigated within the sub-basin within the five-year period preceding the date of the receipt of the Petition. “Irrigate” is defined at A.R.S. § 45-402(18) to mean “to apply water to two or more acres of land to produce plants or parts of plants for sale or human consumption, or for use as feed for livestock, range livestock, or poultry, as such terms aredefined in section 3-1201.” For purposes of this analysis, the Petition is considered by the Department to have been received in full on March 6, 2015, when the Department received a supplemental petition form providing an authorized signature for Chapman Farms, LLC, as described in Part II below.
Landsat satellite imagery (Path 35, Rows 37 and 38) was acquired on-line from the USGS website for the following dates: 7/11/2009; 6/12/2010, 7/6/2010 and 8/15/2010; 6/15/2011; 6/9/2012; 5/19/2013 and 6/4/2013; 6/7/2014; and 2/2/2015. February 2, 2015 was selected as it is the date closest to the date of the submittal of the Petition for which Landsat imagery of the San Simon Valley Sub-basin was available. The other dates were selected during the peak irrigation demand season so that irrigated lands could be more readily distinguished from non-irrigated lands. Landsat images have a 30-meter resolution, so irrigated fields two or more acres in size can readily be discerned.
Prior to the Department’s analysis, the Landsat images were processed by the Department’s Geographic Information System (GIS) staff who selected spectral bands 1, 2, 3, 4, 5 and 7 for Landsat 5 and 7 images to emphasize vegetation in the images. Spectral bands 2, 3, 4, 5, 6 and 7 were used for Landsat 8 images for the same purpose. The images were processed in ERDAS Imagine 2014 so that they could be displayed as layers within the Department’s GIS computer program (ESRI ArcGIS 10.2). For each year of the analysis, the satellite imagery was overlaid with the shapes of Cochise County assessor parcels (acquired from Cochise County on February 10, 2015). Department analysts then selected each parcel that appeared to be irrigated and the Cochise County Assessor ownership information (as provided by Cochise County on February 25, 2015) for that parcel was automatically placed in a data table.
For parcels whose irrigation status remained uncertain after review of Landsat imagery, the Department studied imagery available on Google Earth™ from May 20, 2011 and/or December 6, 2013. Google Earth™ was also used to search for irrigation uses, such as vineyards, which may not provide a signal readily visible in Landsat imagery because of the spacing of the vines. USGS crop survey information from October 2014, which mapped a category described as "young pecans", was also used to verify the irrigation status of some parcels. Orchards of young pecans may not be readily visible in Landsat imagery because of the spacing between trees.
Google™ was used to search data available via the internet for vineyards located within the San Simon Valley Sub-basin. When vineyards two or more acres in size were identified, their ownership information was added to the data table.
The Landsat imagery analysis described above was completed by two independent Department analysts. In addition, the Department used ERDAS Imagine software to perform an automatic classification to identify irrigated parcels two or more acres in size on each of the images based on the spectral signature of the agriculture. The parcels selected by the classification analysis were then cross-checked by Department staff and added to the data table, when appropriate.
The Arizona State Land Department (ASLD) website was used to locate agricultural leases within the San Simon Valley Sub-basin. The Landsat imagery analysis described above was then used to determine which of the leases had been irrigated during the five years preceding the receipt of the Petition. The list of lease numbers was e-mailed to ASLD, and ASLD returned a list of the lessees of those identified leases.
The Department then evaluated the data table of “irrigation users of groundwater” produced during the Landsat imagery analysis to determine whether each of the petitioners had irrigated at least one parcel of two or more acres during the five years preceding the receipt of the Petition. The Department verified that 16 petitioning individuals/entities listed in the table above qualified as “irrigation users of groundwater”. Several petitioners also irrigated ASLD leased agricultural land. Where the same entity irrigated both privately-owned land and state-owned land, the entity was counted as a single “irrigation user of groundwater”.
The data table of “irrigation users of groundwater” was then sorted by landowner, as identified by Cochise County Assessor records, so that a list of landowners who had irrigated at least one parcel of two or more acres during the five years preceding the receipt of the Petition could be compiled. The Department determined that there were a total of 33 non-petitioning landowners on this list. The list of 33 landowners was then compared to the list of ASLD agricultural lessees where irrigation had occurred in the last five years to determine whether there were any lessees with unique names not found on the list of 33 landowners. One such lessee was initially identified, but subsequently removed from the list after the Department received documentation demonstrating that the agricultural lease was being irrigated by a previously identified entity also irrigating privately-owned land. In addition, the parcel owners of the property identified as “MASSEY BILLY FRED REV TRUST” provided documentation that the property is being farmed by Massey Farms, Inc. and should not be identified as a separate “irrigation user of groundwater”. The Department has removed “MASSEY BILLY FRED REV TRUST” from the list of non-petitioning landowners.
The Department purchased detailed imagery of the irrigated portions of the San Simon Valley sub-basin that was acquired by satellite on March 13 and 14, 2015. The Department is utilizing this imagery, as well as input from the public, to determine if additional “irrigation users of groundwater” should be added to the list of non-petitioners. The Department has determined that the individuals/entities shown under “Additional Non-Petitioners” in the table above should be considered as “irrigation users of groundwater.”
Map of Irrigated Parcels
A map showing the parcels within the San Simon Valley Sub-basin that the Department believes were irrigated during the time period 2010-2014 is available. The map utilizes infra-red imagery so irrigated lands and other vegetation appear red. Parcels containing the irrigated lands are overlain in light blue.