"significantly depleted" is correct and usable in written English.
You can use it when you want to express the idea that something has been reduced greatly or almost entirely used up. Example: "Our resources have been significantly depleted over the past few years."
The United Nations Food and Agriculture Organization reports that more than 80percentt of the world's fisheries are overexploited, fully exploited, significantly depleted, or recovering from depletion.
"Fish stocks are being significantly depleted".
Jewish organizations like B'nai B'rith remained behind with a significantly depleted membership.
Unemployment created by years of drought has significantly depleted the country's agricultural base, particularly in the north-east, causing a mass rural flight to the cities.
The report says there is a high probability that occupations such as accountants, estate agents and economists will not exist or will be significantly depleted by the 2030s.
But the stark reality is that we now know the earth's oil and gas reserves pretty well and most of the readily accessible ones are significantly depleted.
It's pointless to talk about a "best" member of Fleetwood Mac, for without any of them the band are significantly depleted.
The current champions struggled to see off the resilient challenge of a significantly depleted Castleford, who had reason to feel aggrieved that a crucial second‑half decision went against them.
"I think that the arsenal of many central banks has been significantly depleted and we no longer have many of the options that existed in years past," said Eric R Peterson, partner at consultancy giant A T Kearney.
Kwan got to her feet, continued her routine and went on to compete for her fifth national title tonight against a women's field that was significantly depleted by the growing problem of injuries from high-impact landings.
Nickel (Ni) was significantly depleted from the solar abundance.
