Please remember to let people know not to dump leaves into the ravine. While the ravine can handle the natural leaf fall from its own trees, added leaves from outside the ravine clump and create an impenetrable layer that will prevent the growth of native plants next spring.
If heavily treed yards are creating more leaves than you can handle, try mowing over the leaves with a mulching mower first to reduce the leaves to flakes. Then if there are still too many flaked leaves, vacuum up the flakes with the bag on the mower. The flaked leaves take up only about 10-15% of the originals, and they decompose much faster when put in a mulch pile. They’re also very good for a winter top dressing on gardens. Then next spring just dig them into the gardens they mulched for added organic matter. Use specific leaves for mulch, such as oak and other acidic leaves around azaleas and other acid loving plants.