In this year's first quarter, we achieved consolidated earnings of $0.52 per share versus $0.38 per share during the first quarter of 2020.
That's a 37% increase or a 21% increase on an adjusted basis.
We continue to execute on our business strategies in the quarter, provide high-quality water, wastewater and electric services to over 1 million people and make timely investment in our systems, all while keeping our unwavering commitment to reliability and safety.
I'm pleased to report that the company had a great quarter with consolidated earnings of $0.52 per share as compared to $0.38 per share last year.
Excluding the $0.05 per share loss on an investment item from the first quarter of last year, earnings for the first quarter of 2021 increased by $0.09 per share or 20.9% as compared to last year.
For our water utility subsidiaries, Golden State Water Company, earnings were $0.33 per share as compared to $0.29 per share, as adjusted to exclude the $0.05 per share loss on investments incurred in the first quarter of last year.
Our Electric segment's earnings for the first quarter of 2021 were $0.07 per share as compared to $0.06 per share for the first quarter of 2020 due to an increase in electric rate and a decrease in interest expense.
Earnings from our Contracted Services segment increased $0.04 per share for the quarter.
We still expect the Contracted Services segment to contribute $0.45 to $0.49 per share for this year.
Our consolidated revenues for the first quarter increased by $8 million as compared to the same period in 2020.
Water revenues increased $3.6 million during the quarter, due to third year step increases for 2021 as a result of passing earnings tax.
Contracted Services revenues for the quarter increased $3.8 million, largely due to an increase in construction activity, resulting from timing differences of when construction activity was performed as compared to the first quarter of last year.
Our water and electric supply costs were $22.6 million for the quarter, an increase of $1.3 million from the same period last year.
Consolidated expenses increased $1.7 million as compared to the first quarter of 2020.
Interest expense, net of interest income and other decreased by $2.5 million due primarily to gains on investments held for retirement benefit plan compared to losses incurred during the first quarter of last year as previously discussed.
Net cash provided by operating activity was $24.7 million as compared to $15.7 million in 2020.
Our regulated utility invested $35.8 million in company-funded capital projects during the quarter, and we estimate our full year 2021 company-funded capital expenditures to be $120 million to $135 million.
In addition, we intended to prepay the entire $28 million of Golden State Water's 9.56% notes issued in 1991 and due in 2021 later this month.
The early redemption will include a premium of 3% of par value or $840,000 if redeemed before May 15, 2022.
As a result, rate increases are expected to generate an additional $11.1 million in the adopted water gross margin for 2021 as compared to the adopted water gross margin for 2020.
We requested a capital structure of 57% equity and 43% debt, which is our currently adopted capital structure, a return on equity of 10.5% and a return on rate base of 8.18%.
Among other things, Golden State Water requested capital budgets of approximately $450.6 million for the three-year rate cycle and another $11.4 million of capital projects to be filed for revenue recovery through advice letters when those projects are completed.
The weighted average water rate base has grown from $752.2 million in 2018 to $980.4 million in 2021, compound annual growth rate of 9.2%.
ASUS' earnings contribution increased by $0.04 per share versus last year's first quarter to $0.12 per share, due to an overall increase in construction activity resulting from timing differences of when work was performed as compared to the first quarter of last year and lower legal fees and outside services expenses.
We reaffirm our projection that ASUS will contribute $0.45 to $0.49 per share for 2021.
Each quarter, I'd like to remind everyone of our long and consistent history of dividend payments, dating back to 1931, in addition to our unbroken 66 year history of annual dividend increases, which places us in an exclusive group of companies on the New York Stock Exchange.
In the past decade, our Board of Directors has raised the dividend at a compound annual growth rate of 9.4%, in line with our dividend policy, providing a compound annual growth rate of more than 7% over the long term.

Summary:
In this year's first quarter, we achieved consolidated earnings of $0.52 per share versus $0.38 per share during the first quarter of 2020.
I'm pleased to report that the company had a great quarter with consolidated earnings of $0.52 per share as compared to $0.38 per share last year.