Our appreciation and recognition also extends to our 700 plus employees and their utility industry peers across the nation, who we consider to be essential as they continue to deliver safe and reliable service.
Our dedicated and passionate water professionals met the challenges of 2020 head on to provide a reliable supply of safe drinking water to more than 1.6 million people in our local service communities in California, Connecticut, Texas and Maine.
In my 38 years in this profession, it never mattered more.
For example, in 2020, San Jose Water was responsible for $28.8 million of diverse supplier spend, representing 30.1% of our addressable spend there.
Other highlights of 2020 include investing more than $199 million in our water and wastewater systems across our multistate footprint, achieving world-class customer satisfaction on a composite basis across the Company and another successful year of meeting drinking water and environmental regulations, delivering on our commitment to public health and environmental stewardship.
Fourth quarter revenue was $135.7 million, a $9.9 million increase over reported fourth quarter 2019 revenue.
Net income for the quarter was $13.3 million or $0.46 per diluted share.
This compares with a net loss of $5.5 million or $0.19 per diluted share for the fourth quarter of 2019.
Diluted earnings per share for the quarter reflects lower CTWS merger expenses of $0.36 per share, higher customer usage of $0.22 per share and lower administrative and general expenses of $0.19 per share due to lower integration costs.
These increases were partially offset by an increase in production costs due to higher usage of $0.10 per share and a decrease of $0.05 per share due to lower local surface water availability in Northern California.
Turning to our comparative analysis for the quarter, our $9.9 million revenue increase was primarily due to increased customer usage of $6 million and $1.4 million in cumulative rate increases.
In addition, we recorded $2.8 million in customer rate credits in the fourth quarter of 2019 as a result of regulatory commitments we made in connection with the merger.
Water production expenses increased $3.6 million compared to the fourth quarter of 2019.
The increase included $2.6 million in higher customer usage and $1.5 million for the purchase of additional water supply necessary to supplement California surface water.
Other operating expenses decreased $12 million during the quarter, primarily due to lower merger-related expenses of $9.7 million and lower general and administrative expenses of $5.1 million due to lower merger-related integration costs.
These decreases were partially offset by $2.5 million in higher depreciation expense.
The effective income tax rate for the fourth quarter was a negative 7% compared to 6% for the fourth quarter of 2019.
Turning to our annual results, 2020 revenue was $564.5 million, a 34% increase over the same period last year.
Net income in 2020 was $61.5 million or $2.14 per diluted share compared to $23.4 million or $0.82 per diluted share during the same period in 2019.
CTWS customer usage contributed $2.83 per share and customer usage from our other operations increased $0.59 per share.
Due to the timing of when the merger transaction closed in 2019, we only recorded $0.01 per share of earnings from CTWS in 2019.
In addition, 2019 non-recurring merger costs contributed $0.48 per share and the WCMA write-off in 2019 contributed $0.29 per share.
These increases were partially offset by increased production costs of $1.04 per share due to higher usage, a net increase in interest on long-term debt of $0.86 per share due primarily to merger-related debt, and 2020 note issuances and a decrease in local surface water availability in Northern California of $0.58 per share.
Our 2020 increase in revenue was primarily due to $111.2 million in increased customer usage, $12.2 million in cumulative rate increases and $2.7 million from new customers.
Water production expenses increased $50 million in 2020.
The increase was primarily due to $33.9 million in higher customer water usage from the addition of CTWS and drier weather, and a $19 million increase due to lower surface water supplies.
This increase was partially offset by $3.4 million of increase in California cost recovery balancing and memorandum accountants.
Other operating expenses increased $33.9 million in 2020, primarily due to a $23.7 million increase in depreciation expense, $13.4 million in higher general and administrative expenses and $10.8 million in higher property and other non-income taxes.
In addition, in 2019, we incurred $15.8 million in merger expenses related to the merger transaction.
Other income and expense for the year included $13 million of new interest on SJW Group's $510 million senior notes, which were issued in October of 2019 and a $50 million senior note issued by SJW Group in August of 2020, as well as $8 million of interest expense on CTWS financings.
Other expense and income in 2019 included $6.5 million of interest income earned on the proceeds of the Company's December 2018 equity offering.
Turning to our capital expenditure program, we added approximately $65 million in Company-funded utility plant in the fourth quarter of 2020, bringing total Company-funded additions to $199.3 million.
Our 2020 cash flows from operations decreased approximately $25.9 million over the same period in 2019.
The decrease was primarily due to the authorized collection of $45.3 million of balancing and memorandum accounts in 2019, a decrease in collections of previously billed and accrued receivables of $15 million, a decrease in other non-current assets and liabilities of $12.4 million and a $50 million upfront payment we made to the city of Cupertino in connection with our service concession agreement.
These decreases were partially offset by a $51.8 million increase in net income adjusted for non-cash items.
SJWC has determined that future recovery of the account is probable and recognized a regulatory asset of $2.3 million in the SEMA-related to COVID-19 for the year ended December 31, 2020.
At the end of 2020, we had $84.9 million available on our bank lines of credit for short-term financing of utility plant additions and operating activities.
The average borrowing rate on line of credit advances during 2020 was approximately 1.78%.
In the last decade alone, more than $1 billion has been invested in the local water systems of the communities that we serve.
In 2021, SJW Group's subsidiaries plan to invest $239 million in infrastructure improvements to serve our customers in California, Connecticut, Maine and Texas.
Over $1 billion is planned across the organization over the next five years.
San Jose Water's GRC application proposes a $435 million capital program for the years 2021 through 2023, supported by our award-winning enterprise asset management plan.
The process is expected to take about 12 months, and new rates are anticipated in January 2022.
A primary driver of the case is the $266 million in infrastructure investments that have been completed and are providing a benefit to customers but are not yet covered in rates.
Earlier this year, PURA approved a 1.1% increase in infrastructure surcharges through the water infrastructure and conservation adjustment program, or WICA, this request covers $8.7 million in qualified infrastructure investments with incremental annual revenue of about $1 million.
The increases were effective on January 1, recognizing $3.5 million in critical infrastructure investments and increasing revenues by about $300,000.
Our operation located in the fast-growing region in between Austin and San Antonio, serves 20,000 customer connections.
To achieve our goals, we are working diligently to support the growth of our Texas Water Utility, which has more than tripled in size through organic growth and acquisitions since 2006, increased our capital investments to deliver safe and reliable service to our local communities and grow the rate base for all of our operating entities and continue to seek acquisition opportunities that create value for our stakeholders.
The prudent management of our business and financial resources continues to be fundamental to our growth and ability to return capital to shareholders, demonstrating the Company's strong commitment to our shareholders in January 2021, the Board authorized a 6.3% increase in SJW Group's 2021 dividend to $1.36 per share as compared to the total dividends paid in 2020.
We're proud to have continuously paid a dividend for over 77 years and to have increased that annual dividend in each of the last 53 years, delivering value to our shareholders.

Summary:
Fourth quarter revenue was $135.7 million, a $9.9 million increase over reported fourth quarter 2019 revenue.
Net income for the quarter was $13.3 million or $0.46 per diluted share.