
	Federal		State		Total
2020
Current	$	—	$	3	$	3
Deferred	14,692		(2,677)		12,015
Total income tax	$	14,692	$	(2,674)	$	12,018
2019
Current	$	—	$	3	$	3
Deferred	15,582		2,086		17,668
Total income tax	$	15,582	$	2,089	$	17,671
2018
Current	$	—	$	3	$	3
Deferred	15,995		(126)		15,869
Total income tax	$	15,995	$	(123)	$	15,872

The Company's 2020, 2019 and 2018 qualified tax repairs and maintenance deductions totaled $164.0 million, $70.0 million, and $102.0 million, respectively.

At December 31, 2020, the Company had U.S. federal and U.S. state tax net operating loss carryforwards of approximately $140.8 million and $181.3 million respectively. The U.S. federal and U.S. state net operating loss carryforwards will expire at various dates beginning in tax years 2027 and 2028, respectively.

As of December 31, 2020, the California Enterprise Zone (EZ) credit was $4.2 million net of federal tax benefit for qualified property purchased before January 1, 2015, and placed in service before January 1, 2016. The Company has carry-forward California EZ credits of $2.2 million net of federal tax benefit. Unused State of California EZ credits can carry-forward until 2024.


	2020		2019		2018
Statutory income tax	$	22,858	$	16,965	$	17,105
Increase (reduction) in taxes due to:
State income taxes net of federal tax benefit	7,598		5,639		5,685
Effect of regulatory treatment of fixed asset differences	(9,201)		(3,696)		(5,954)
Investment tax credits	(74)		(74)		(74)
AFUDC equity	(1,392)		(1,870)		(1,106)
Share based stock compensation	523		302		(278)
TCJA refund	(9,470)		—		—
Other	1,176		405		494
Total income tax	$	12,018	$	17,671	$	15,872

The effect of regulatory treatment of fixed asset differences includes estimated repair and maintenance deductions and asset related flow through items.

On December 22, 2017, the U.S. government enacted expansive tax legislation commonly referred to as the TCJA. Among other provisions, the TCJA reduces the federal income tax rate from 35 percent to 21 percent beginning on January 1, 2018 and eliminated bonus depreciation for utilities. The TCJA required the Company to re-measure all existing deferred income tax assets and liabilities to reflect the reduction in the federal tax rate. A TCJA refund of $108.0 million was recorded on December 31, 2017.

During 2020, the Company analyzed its deferred tax balances, tax regulatory asset and tax regulatory liability based on 2018 GRC approved rates. As of December 31, 2020, the TCJA refund was $105.0 million. The Company continued working with other state regulators to finalize the refund to ensure compliance with federal normalization rules.


	2020		2019
Deferred tax assets:
Developer deposits for contributions in aid of construction	$	29,491	$	25,114
Net operating loss carryforward and tax credits	37,326		11,029
Pension liability	12,031		10,095
Income tax regulatory liability	41,151		47,196
Operating leases liabilities	4,372		4,024
Other	2,812		2,975
Total deferred tax assets	127,183		100,433
Deferred tax liabilities:
Property related basis and depreciation differences	350,923		297,470
WRAM/MCBA and interim rates balancing accounts	39,107		17,771
Operating lease-right to use asset	4,362		4,030
Other	8,823		3,752
Total deferred tax liabilities	403,215		323,023
Net deferred tax liabilities	$	276,032	$	222,590

A valuation allowance was not required at December 31, 2020 and 2019. Based on historical taxable income and future taxable income projections over the period in which the deferred assets are deductible, management believes it is more likely than not that the Company will realize the benefits of the deductible differences.


	December 31, 2020		December 31, 2019		December 31, 2018
Balance at beginning of year	$	11,008	$	9,716	$	11,058
Additions for tax positions taken during current year	2,952		1,292		1,787
Reduction to prior year tax position	—		—		(3,129)
Balance at end of year	$	13,960	$	11,008	$	9,716

The Company does not expect a material change in its unrecognized tax benefits within the next 12 months. The component of unrecognized tax benefits that, if recognized, would affect the effective tax rate as of December 31, 2020, was $3.7 million, with the remaining balance representing the potential deferral of taxes to later years.