Shrinkage Factors

As you make gas purchases, be sure to take gas shrinkage into account. Shrinkage gas is necessary to provide compressor fuel and to replace lost and unaccounted for (LUAF) gas supplies. Shrinkage gas is supplied in-kind by the shipper. That is, shippers must supply more gas at a California Gas Transmission receipt point than they receive at the delivery point. The difference is shrinkage.

Current and historical shrinkage rates are shown below. Shrinkage formulae and examples are available at Calculating Shrinkage.

Transmission Shrinkage

  Redwood to Off-system Mission Path All Other Transmission Paths Storage Injection
As of Apr. 1, 2023 0.9% 0.0 1.3% 0.7%
As of Nov. 1, 2022 0.9% 0.0 1.3% 0.9%
As of Apr. 1, 2021 0.9% 0.0 1.2% 0.9%
As of Nov. 1, 2020 0.9% 0.0 1.3% 0.9%
As of Nov. 1, 2019 0.9% 0.0 1.2% 0.9%
As of Nov. 1, 2018 0.8% 0.0 1.1% 0.9%
As of Nov. 1, 2017 0.9% 0.0 1.2% 0.9%
As of Apr. 1, 2017 0.9% 0.0 1.2% 0.9%
As of Nov. 1, 2015 0.9% 0.0 1.2% 1.0%
As of Apr. 1, 2015 0.9% 0.0 1.1% 1.0%
As of Nov. 1, 2014 0.9% 0.0 1.1% 1.2%
As of Apr. 1, 2014 0.9% 0.0 1.0% 1.2%
As of Nov. 1, 2011 0.9% 0.0 1.0% 1.1%
As of May 1, 2011 0.9% 0.0 0.8% 1.1%
As of Jan. 1, 2011 0.9% 0.0 1.1% 1.1%
As of Nov. 1, 2009 1.0% 0.0 1.4% 1.1%
As of Nov. 1, 2008 0.9% 0.0 1.3% 1.1%
As of Nov. 1, 2006 0.9% 0.0 1.3% 1.1%
As of Apr. 1, 2006 0.9% 0.0 1.2% 1.1%
As of Mar. 1, 2006 0.9% 0.0 1.2% 1.0%
As of Apr. 1, 2005 1.0% 0.0 1.2% 1.0%
As of Jan. 1, 2005 1.0% 0.0 1.2% 0.8%
As of May 1, 2004 1.11% 0.0 1.2% 0.8%
As of Jan. 1, 2004 1.11% 0.0 1.2% n/a
As of Mar. 1, 2003 1.11% 0.0 1.35% n/a
As of Mar. 1, 2002 1.11% 0.0 0.79% n/a
As of Jan. 1, 2002 1.11% 0.0 1.35% n/a
As of Oct. 1, 2000 1.11% 0.0 1.37% 0.0
As of Nov. 2, 1998 1.11% 0.0 1.73% n/a
As of Sep. 1, 1998 1.11% 0.0 1.73% n/a
As of Mar. 1, 1998 1.11% 0.0 1.72% n/a

Distribution Shrinkage

  Season Core Noncore on Distribution System Noncore on Local Transmission System
As of Nov. 1, 2022 Summer (Apr - Oct) 1.0% 0.2% 0.0
Winter (Nov - Mar) 3.7% 0.2% 0.0
As of Apr. 1, 2021 Summer (Apr - Oct) 0.8% 0.1% 0.0
Winter (Nov - Mar) 2.7% 0.1% 0.0
As of Nov. 1, 2020 Summer (Apr - Oct) 1.2% 0.2% 0.0
Winter (Nov - Mar) 3.1% 0.2% 0.0
As of Nov. 1, 2019 Summer (Apr - Oct) 1.9% 0.2% 0.0
Winter (Nov - Mar) 3.7% 0.2% 0.0
As of Nov. 1, 2018 Summer (Apr - Oct) 2.2% 0.2% 0.0
Winter (Nov - Mar) 3.6% 0.2% 0.0
As of Nov. 1, 2017 Summer (Apr - Oct) 1.8% 0.2% 0.0
Winter (Nov - Mar) 3.5% 0.2% 0.0
As of Nov. 1, 2015 Summer (Apr - Oct) 2.4% 0.1% 0.0
Winter (Nov - Mar) 3.2% 0.1% 0.0
As of Nov. 1, 2014 Summer (Apr - Oct) 1.6% 0.1% 0.0
Winter (Nov - Mar) 3.0% 0.1% 0.0
As of Nov. 1, 2011 Summer (Apr - Oct) 1.7% 0.2% 0.0
Winter (Nov - Mar) 2.9% 0.2% 0.0
As of May 1, 2011 n/a 0.9% 0.2% 0.0
As of Jan. 1, 2011 n/a 2.6% 0.2% 0.0
As of Nov. 1, 2009 n/a 3.0% 0.2% 0.0
As of Nov. 1, 2008 n/a 3.3% 0.2% 0.0
As of Nov. 1, 2006 n/a 3.1% 0.2% 0.0
As of Mar. 1, 2006 n/a 2.9% 0.2% 0.0
As of Apr. 1, 2005 n/a 2.1% 0.2% 0.0
As of Jan. 1, 2005 n/a 2.1% 0.2% 0.0
As of May 1, 2004 n/a 2.4% 0.2% 0.0
As of Jan. 1, 2004 n/a 2.4% 0.2% 0.0
As of Mar. 1, 2003 n/a 2.41% 0.16% 0.0
As of Mar. 1, 2002 n/a 1.88% 0.12% 0.0
As of Jan. 1, 2002 n/a 2.41% 0.16% 0.0
As of Oct. 1, 2000 n/a 2.31% 0.16% 0.0
As of Nov. 2, 1998 n/a 4.02% 0.22% 0.0
As of Sep. 1, 1998 n/a 4.02% 0.22% 0.0
As of Mar. 1, 1998 n/a 3.31% 0.21% 0.0

If you have any questions regarding these shrinkage rates, please contact your CGT representative.