As an income investor, you're probably allured by high-yield dividend stocks. There's nothing wrong with that, except that the stock picks would be better poised to make you money if those high yields are backed by steadily growing earnings and dividends.

Trust me, there are several such gems hidden in the market today; some offer yields as high as 5% or more and are well-poised to continue doing so for years to come. Two such stocks that I'd urge you to look at are Brookfield Renewable Partners (BEP -1.71%) and Welltower Inc. (WELL -0.64%). Note that Welltower is about to change its stock ticker from HCN to WELL, effective Feb. 28.

There's a strong reason for choosing these two stocks over others: Both have solid megatrends backing their growth potential, which means they're likely to offer sustainable high yields to shareholders for years to come. Here's why.

Brookfield Renewable Partners: Dividend yield 6.1%

The big switch to renewable energy across the globe is already under way, and companies that have made headway into clean-energy sources stand a chance to win big as the trend catches up. This is even more so when the company in question is one of the world's largest publicly traded pure-play clean-energy companies, like Brookfield Renewable Partners.

Young plants growing in a stack of coins on soil

Image source: Getty Images.

At last count, Brookfield operated 841 power-generating facilities worth nearly $40 billion with 16,400 megawatts of capacity. Hydroelectric power makes up 82% of the company's generation, giving it a huge leeway in a niche clean-energy space that isn't as intensely competitive as solar, or even wind.

Brookfield's business strategy is easy to understand: acquire high-quality renewable assets at low prices and convert them into cash-flow generation machines. Of course, it isn't as simple to make assets profitable, but Brookfield has done well so far, largely because 92% of its revenue is contracted. Since 2012, Brookfield has grown its funds from operations (FFO) and dividend per share (or distribution per unit) at compounded average annual rates of 8% and 6%, respectively.

Brookfield recently delivered solid numbers for 2017, growing its FFO by nearly 39% to $581 million, driven partly by investments worth nearly $625 million on acquisitions. Long term, Brookfield aims to spend $600 million to $700 million annually on buying "high-quality" assets, and earn 12% to 15% returns on investment.

What should matter to you is Brookfield's aim to grow its distribution per unit by 5% to 9% annually, backed largely by organic growth. In other words, the company is confident of generating strong cash flows from its existing assets, even as it continues to solidify its portfolio further with opportunistic investments. For shareholders, this strategy should translate into fatter dividend paychecks and high yields year after year.

The best part? You can buy this high-potential stock for under 12 times cash flow and pocket a hefty dividend yield of 6.1% today.

Welltower: Dividend yield 6.5%

Much like Brookfield, Welltower is preparing to cash in on another big trend: an aging population that's going to drive healthcare spending higher.

Welltower is a healthcare real estate investment trust (REIT) that buys out healthcare properties dealing in senior housing, post-acute care, and outpatient medical solutions, and leases them out to established healthcare providers to jointly operate and develop. The company currently has 1,279 healthcare properties under its belt.

There's massive potential in healthcare, with the U.S. Census Bureau projecting the population of people over 85 will double in 20 years. Welltower gets nearly 70% of its revenue from senior housing.

Since 2011, Welltower's FFO has grown more than sixfold, and its dividends have risen alongside, as reflected in the stock's incredible total returns over the years:

HCN Chart

HCN data by YCharts.

As for dividends, Welltower has increased its dividend for eight consecutive years now, and currently yields a tidy 6.5%. Management is "comfortable" with its current dividend level, having paid out roughly 83% of its FFO in dividends last year, which means there's little reason to believe that the company won't continue its dividend streak.

For shareholders, Welltower's strong foothold in a defensive and high-potential sector like healthcare should reap rich rewards in the long run, in the form of both higher dividends and stock appreciation. With the stock currently trading at a price-to-cash-flow ratio of only 13, which is far below its five-year average, you might want to get serious about adding it to your portfolio.