You'd need all intakes (e.g., downpipes from gutters) to be protected with mesh, the tank itself to have likewise, but the most painful bit is handling those in

You'd need all intakes (e.g., downpipes from gutters) to be protected with mesh, the tank itself to have likewise, but the most painful bit is handling those intakes/overflows getting blocked by leaves/debris. My pipes get blocked by leaves even without mesh. There are a variety of angled mesh systems you can use but adding them to each down-pipe gets expensive.