Randy Jackson Senior County Hydrologist
Inyo County Water Department 
Report 2005-1 
June 30, 2005

INTRODUCTION

The Bishop Cone audit is an annual accounting of Los Angeles Department of Water and Power's (LADWP) groundwater extraction and water usage on Los Angeles-owned lands on the Bishop Cone. Section VII.A of the Inyo County/Los Angeles long-term groundwater management agreement provides that, "Before the Department may increase groundwater pumping above present levels, or construct any new wells on the [Bishop] Cone, the Technical Group must agree on a method for determining the exact amount of water annually used on Los Angeles-owned lands on the Cone. The agreed upon method shall be based on a jointly conducted audit of such water uses." (See Appendix A of this report for Section VII.A of the Inyo County/Los Angeles long-term groundwater management agreement).

At its October 17, 1995 meeting, the Technical Group agreed to recommend to the Inyo County/Los Angeles Standing Committee the description of a Bishop Cone audit procedure to be incorporated into the Green Book. That audit procedure is attached (See Appendix A of this report for section IV.D of the Green Book). The Green Book is the technical appendix to the long-term agreement. The Inyo County/Los Angeles Standing Committee adopted the procedure on November 7, 1996 as section IV.D of the Green Book.

WATER USES ON LADWP-OWNED LAND ON THE BISHOP CONE

Section IV.D.1.a. of the Green Book states, "For the purposes of the Bishop Cone audit, water usage on Los Angeles-owned land on the Bishop Cone is defined as the quantity of water supplied to such land, including conveyance losses, less any return flow to the aqueduct system" (See Appendix A). Table 1, below, is a compilation of water usage in acre-feet (AF) on LADWP-owned land on the Bishop Cone for the runoff years of 2003-2004 and 2004-2005.

TABLE 1. WATER USES ON LOS ANGELES-OWNED LAND ON THE BISHOP CONE. 

*1 A runoff year is defined as starting April 1st and ending March 31st of the following year. 
*2 Accounts were first listed in the 2002-2003 runoff year. The accounts (BAGOLF, BA005A, BA005B and BA006A) are active water use accounts, but in the past have been denied by Inyo for lack of measuring devices. A device has been installed at BA005A this runoff year. Devices have not yet been installed at accounts BA006A, BAGOLF and BA005B). NO DATA -The Account was not active, no data was reported. 0.00-The account was active, no use was reported, data was 0.00 acre-feet. 
*3 New accounts, field inspection performed and accounts credited.

Figure 1, below, is a bar graph comparing water use in LADWP account numbers on the Bishop Cone for runoff years 2003-2004 and 2004-2005. In general, there was an increase in water use, on most accounts from runoff years 2003-2004 to 2004-2005 as well as an overall total increase in water use of 886.95 acre-feet. Three of the new accounts first reported in 2002-2003 have reported uses in

2004-2005 (See Table 1, BA005A, BA005B and BA006A). An additional measuring device has been installed to measure water use associated with account BA005A. The Parashall Flume was inspected on June 17, 2005. The reported use for this account was credited. No additional measurement devices were installed for Accounts BA005B and BA006A and as a result no credit for reported uses was granted for these accounts this runoff year. A field inspection was performed on BA324 and BA500 and reported uses were credited.

TOTAL LADWP GROUNDWATER EXTRACTION ON LADWP-OWNED LAND ON THE BISHOP CONE FOR RUNOFF YEARS 2002-2003 AND 2003-2004

Section IV.D.1.d of the Green Book states, "Total groundwater extraction by LADWP will be compared with corrected water usage on the Bishop Cone for the runoff year. Total groundwater extraction is defined as the sum of all groundwater pumped by LADWP plus the amount of artesian water that flowed out of LADWP uncapped wells on the Bishop Cone during the runoff year."

Total groundwater LADWP extraction and groundwater extraction classified as flowing and pumped groundwater in acre-feet, on the Bishop Cone for the runoff years of 2003-2004 and 2004-2005, are shown in Table 2, below. 

Total groundwater extraction and groundwater extraction classified as flowing and pumped groundwater in acre-feet on LADWP-owned land on the Bishop Cone are shown in a bar chart in Figure 2, below.

COMPLIANCE WITH THE INYO COUNTY/LOS ANGELES LONG-TERM GROUNDWATER MANAGEMENT AGREEMENT

The Inyo County/Los Angeles long-term groundwater management agreement provides that, during any runoff year, total groundwater extraction by LADWP on the Bishop Cone shall not exceed water usage on Los Angeles-owned land on the Cone.  Table 3, below, shows that LADWP was within compliance with the above provision for runoff years 2003-2004 and 2004-2005.