Kinder Morgan (NYSE: KMI) is America's largest energy transportation company and a longtime favorite of high-yield income investors. When doing your homework on investments, though, you need to also look at both the reasons it could succeed and what could cause it to fall. In the case of Kinder Morgan, there are two key issues threaten both its share price and future dividend growth prospects: regulatory risk to its largest growth project and the effects of low oil prices on its most profitable business segment. Let's take a look at how these risks could impact the company and whether they are enough to shy away from investing in Kinder Morgan.  

Transmountain regulatory risk threatens growth backlog
One of the most important factors in Kinder Morgan's current dividend growth plan -- 15% growth in 2015 and 10% for 2016 through 2020 -- is its current growth project backlog. This includes only projects that have secured contracts or are in advanced negotiations and are expected to be completed within the next five years. 

Source: Kinder Morgan investor presentation. 

Kinder's single largest project is Kinder Morgan Canada's Trans Mountain Pipeline Expansion, a $5.4 billion endeavor that would almost triple the existing pipeline's capacity from 300,000 barrels per day to 890,000 barrels per day.

While the project is scheduled to go online in the third quarter of 2018, it has been plagued by years of court battles and has yet to receive final regulatory approval from Canada's National Energy Board.

The most recent setback for this project -- which makes up 30% of Kinder's current growth backlog -- is a new report commissioned by the city of Vancouver that concludes that an oil spill from the pipeline could threaten up to 1 million citizens with exposure to toxic benzene fumes and kill up to 100,000 birds. 

Vancouver Mayor Gregor Robertson is one of the project's most outspoken critics, and he last month called on the City Council to reaffirm its opposition to the project -- a stance the city first took in December 2013.

Today we heard overwhelming evidence that the Kinder Morgan pipeline proposal and the oil tankers associated with it are incredibly disastrous for Vancouver. ... My mind is clearly made up. I think this is a bad deal for Vancouver.

While it might not be surprising that a study funded by adamant opponents to the project found it might come with potentially disastrous risks, sufficient political pressure might kill the pipeline expansion's opportunity to gain final regulatory approval from the NEB. That could prove a serious blow to Kinder's current dividend growth plans.

Low oil prices negatively affecting Kinder's most profitable business segment
Over the past two quarters low oil prices have caused Kinder Morgan to remove almost $1.8 billion in CO2 projects from its current growth backlog, including its St. Johns CO2 field and Lobos CO2 pipeline projects.

Kinder still has $3.4 billion in CO2 projects listed under its current backlog, meaning that should oil prices remain low or fall further, up to 19% of its backlog might be delayed by several years. When combined with the regulatory threat to the Trans Mountain Pipeline Expansion, $8.8 billion, or 48%, of the current growth backlog might be at risk. 

What's worse is that Kinder's CO2 business is, by far, its most lucrative segment in terms of return on investment. 

Source: Kinder Morgan Investor presentation.

In fact, as this table shows, the CO2 segment's ROI last year was 11 percentage points higher than the company's next most profitable business, refined product pipelines. This means that, should Kinder's CO2 projects be further delayed, the negative effect on its future projected distributable cash flow -- which anchors the company's projected dividend growth and sustainability estimates -- would be disproportionately higher than the relative size of its CO2 projects backlog might at first indicate.   

The takeaway: not even America's blue-chip dividend pipeline stock is risk free
I believe Kinder Morgan remains one of America's best dividend growth stocks; however, investors must be aware that no company, no matter how large, well diversified, or well managed, is completely risk free. While I fully expect Kinder to live up to its projected dividend growth plans, those estimates are predicated on the successful completion of its enormous growth project backlog. Should Kinder fail to receive final regulatory approval for its Trans Mountain Pipeline Expansion, or if low oil prices result in continued delays to its highly lucrative CO2 project backlog, management might not be able to live up to its current dividend growth guidance.