Dividend-paying stocks can be excellent passive income investments. Many companies offer attractive dividend payments. Even better, unlike fixed-income investments, many dividends steadily grow over time. 

Three dividend stocks a few Fool.com contributors believe are great ones to buy and hold for the long haul are Brookfield Infrastructure (BIPC 1.80%)Enbridge (ENB 0.60%), and American States Water (AWR 2.35%). Here's what makes these three stocks stand out as excellent passive-income investments.  

Yield and growth

Reuben Gregg Brewer (Brookfield Infrastructure): Infrastructure is hugely expensive, but, once built, provides a steady stream of income. That's the logic that underpins the business model of Brookfield Infrastructure Corp. and its sister share structure Brookfield Infrastructure Partners. But what's really interesting here is the way Brookfield Infrastructure (referring to both share classes at once) goes about owning and operating infrastructure assets.

First off, Brookfield Infrastructure is an opportunistic investor. It tries to buy assets when they appear cheap. It then runs them, generally looking for ways to improve performance over time (expansion investments and more efficient operation, for example). Eventually, if it can get a good price, management will sell the asset and start the process over again. Marrying fairly well with this approach is the company's global and industry diversification. It has exposure to North America, South America, Europe, and Asia. And it owns everything from pipelines to utilities to cellular towers. This materially increases the opportunity for finding cheap assets to replace infrastructure that has been sold.

Despite taking an active approach with the portfolio, the company has a stated goal of providing investors with dividend growth of between 5% and 9% a year. It has beaten that promise with an annualized increase of 10% since 2019. There's no reason to doubt it can keep meeting, if not beating, the dividend growth goal.

So far so good, but here's an interesting complication. There are two share classes to choose from. Brookfield Infrastructure is a traditional corporate structure and offers a dividend yield of 3.5%. This share class exists because some institutional investors aren't allowed to own Brookfield Infrastructures Partners, which is a limited partnership. It offers a yield of 4.6%, largely because there's a smaller pool of investors looking at it.

Plenty of fuel sources

Matt DiLallo (Enbridge): Enbridge has been a premier passive income stock over the years. The Canadian energy infrastructure giant has grown its dividend for 28 straight years. The company has plenty of fuel to sustain its 7%-yielding payout for decades to come. 

Powering that view is the company's top-notch energy infrastructure franchise. Enbridge has an almost unrivaled asset footprint, including the best liquids pipeline platform in North America, a nearly unmatched gas transmission network, the largest gas utility in the continent, and a diversified platform of lower-carbon energy businesses. This portfolio positions the company to grow as energy demand increases.

Enbridge believes it can invest more than 1 billion Canadian dollars ($720 million) annually across its four core franchises in the coming years, with similar expansion potential from its emerging new energies platform. It can easily finance that growth while continuing to expand its dividend.

The company has a comfortable dividend payout ratio of 60% to 70% of its free cash flow. That enables it to retain billions of dollars in cash flow each year to finance capital projects. The company also has a strong investment-grade balance sheet, giving it additional borrowing capacity to fund growth. Enbridge estimates it can self-fund CA$6 billion ($4.3 billion) of annual investment spending, which includes capital projects, selective acquisitions, and opportunistic share repurchases.

This investment level should drive mid-single-digit cash-flow-per-share growth in the coming years. That should support dividend growth at around that annual pace. Meanwhile, with its growing investments in lower-carbon energy, Enbridge should be able to sustain its big-time dividend for decades to come.

Reliable dividends

Neha Chamaria (American States Water): American States Water stock has lost roughly 11% value in the past three months. That drop has priced the stock at a point where income investors might want to consider buying so as to lock in decades of passive income.

American States Water recently reported lower-than-expected earnings for its 2022 fourth quarter and full year as it was still awaiting approval for new water rates from the California Public Utilities Commission. If approved, the company will be able to add the new rates retroactively to its revenue from Jan. 1, 2022, which will boost its profits this year.

Most importantly, none of it changes American States Water's capability to pay regular dividends and grow them in the coming years like in the past. The water utility boasts the longest record of consecutive annual dividend increases among all publicly listed companies in the U.S. -- American States Water increased its dividend by 8.9% in 2022, and it was its 68th straight year of annual dividend increases. The company grew its dividend at a compound annual growth rate of 9.2% in the past 10 years. Those dividends, when reinvested, have hugely boosted shareholder returns over the years.

AWR Chart

AWR data by YCharts

Management also reiterated its dividend policy during the fourth-quarter earnings call and confirmed American States Water is targeting more than 7% compound annual growth in dividends in the long term. The 1.8%-yielding stock could comfortably hit that goal, given that it's a highly regulated business that consistently invests in infrastructure to win timely rate base approvals. It's a proven cash-flow-generating business, and that makes American States Water one dividend stock you can bank on for years of extra income.