VENICE — Between efforts to improve the water supply, clean up stormwater runoff and improve wastewater treatments, Sarasota County government and taxpayers have spent almost $1 billion over the past 25 years in improving water quality, county officials said.

Almost half of that has gone to improving stormwater flow in the watershed and reducing nutrients — resulting in improvements such as the Celery Fields and more recently the Dona Bay watershed cleanup of water that flows from Cow Pen Slough.

On Friday, in a preview of a presentation that will be given at a symposium in June, county officials highlighted aspects of those efforts at a joint meeting of the Argus Foundation and the South County Tiger Bay Club, hosted at the Venetian Golf & River Club.