As far as I know, they have always discharged when lake levels got too high but did so primarily in areas south of the lake. They pumped water south towards the Everglades.
According to the following 2016 dated article, in 1999 the US Fish and Wildlife Service closed of large portions of the Everglades to discharge from Lake Okeechobee in order to protect Cape Sable Sparrow nesting habitat.
Environmentalists prevent water nature destined for the Everglades from flowing into the Everglades yet, everybody listens to the media and blames farmers for simultaneously starving the Everglades of water and discharging flood waters into the St. Lucie and Caloosahatchee rivers.
Since 1999, at the direction of the Fish and Wildlife Service, the U.S. Army Corps of Engineers has closed very large water control gates along Tamiami Trail leading into Everglades National Park, preventing their use from November to July every year supposedly to protect the sparrow. This has parched the park and Florida Bay of much needed clean fresh water.http://sunshinestatenews.com/story/saving-endangered-sparrow-and-restoring-balance-everglades-ecosystem-possible-after-all
Lake holding at 14.48 today
due to lack of rain in lower kissimmee ..inflows only 3700 cfs...outflows continue over 3000 cfs from the Chain of lakes into the upper Kissimmee..
outflows have increased to about 1300 south out of the 351 ans 354 canals
the Corps will release their updated plan a couple of hours