The phrase "a substantial stream" is correct and usable in written English.
It can be used to describe a significant flow of something, such as water, information, or resources.
Example: "The river had a substantial stream, providing ample water for the surrounding ecosystem."
Alternatives: "a significant flow" or "a considerable current".
There exists a substantial stream of research on the amount of embodied energy and greenhouse gas emissions associated with nuclear generated electricity.
While the centre commissions a wide range of research, such as studies of alcohol consumption in the armed forces, a substantial stream of research comes under the heading of "information activities and outreach".
It is widely believed that the ownership of such patents is a very valuable bargaining tool in cross-license negotiations, while for non-producing firms such patents may result in a substantial stream of licensing revenues.
The lava flow officially began on June 27, oozing slowly forward and attracting a substantial stream of attention.
A substantial stream of research is built around activity theory.
Loot boxes are a substantial revenue stream for the video game industry.
While on-demand services and Web sales are becoming a substantial revenue stream, more expensive specialty endeavors continue to need theatrical distribution to have any hope of turning a profit.
A substantial literature stream suggests that many products are becoming more modular over time, and that this development is often associated with a change in industry structure towards higher degrees of specialization.
It's at the heart of the battle between broadcasters and cable networks over creating a substantial revenue stream from retransmission fees that can give ad-supported networks a weapon against the subscriber fees that cable networks like ESPN wield like a financial cudgel.
Paid stickers have since become a substantial revenue stream for Line, although far smaller than Line's main one: games.
It has also offered to provide funding in the form of "a substantial revenue stream" to Sky News for 10 years.
