Zebras and quaggas affect every lake differently. Warm lakes get hit harder with the mussels being able to breed constantly. As far as fishing goes, again every lake is different. Lake Havasu is crystal clear now as the mussels are filtering all the algae and plankton out of the water. Red Ear, aka shell crackers, are thriving from feeding off the mussels.Why are we thinking of new ways to tax people? This is not a money problem its a how we choose to deal with it problem. Most every lake I fish in TX has zebra mussels and the water intakes are good and the fishing is as good as ever and you can launch a boat whenever you want anywhere you want.
A lake like Granby would be hit hard if the mussels took hold and had explosive growth, but with the cold water they might not be an issue. If the mussels did though, Kokes would have another organism to compete with in a low nutrient lake.
Lakes like Chatty and Pueblo could see at least a short term benefit. Shad would have competition for food, so there would likely be some decline in their population. Less food, more hungry fish that are easier to catch.
I've inspected San Justo Reservoir in California which is infested with Zebras. They had just drawn down the reservoir 10 feet and the entire shore was completely black. Think an ocean pier pile covered in mussels, but for miles of shore. They were attached to rocks, submerged trees and even the dirt. It stank and you were unable to walk the shore. As deep as I could see into the water, crystal clear at least 30 feet, all I could see was mussels.
Lots of research going on there. USBR's big hope was a coating that had copper in it, because copper kills them quickly. Research found the villagers (larval mussels) kept attaching until there was a layer of dead mussels that shielded the new mussels from the coating. At that point the mussels took off.Whomever invents some kind of coating that the mussels can't attach to will be a millionaire.
Most of the problems caused for water municipalities is in the delivery systems and not the large gates and outletworks. You have to treat the water immediately because they will attach inside your pipes. You then have to filter the villagers out before they travel down the pipe even if they are dead. Any pipe under 12" dia. is very susceptible to clogging or too much loss in flow. This really causes problems in power plants and pumping plants. Raw water is used for cooling and mechanical seal water.
Only places having issues on larger outlets are places like Havasu. The mussels are growing so fast they clog trashracks and gate slots. Most places the mussels can just be knocked off by moving the gates, but they are so prolific at Havasu that they can plug a 12" wide guide.
So in my personal experience, it is worth protecting our lakes, but CPW needs to do a better job of allowing access.