It's Bill that's spent the money on his cussed booze and gambling. Way of the Lawless Max Brand The gambling houses can do it, and so keep on breaking the law.
When Winnie tries to drink, Jesse stops her. Then Mae and Miles appear. Alarmed at Winnie's discovery of the spring, they kidnap her. Winnie learns that the music she heard comes from Mae's music box. She also learns the Tucks' secret: the water in the spring is magic and has made them ageless.
The negative effect of those vacuums is that persons of lesser Intent but stronger Wills can easily manipulate those vacuums to their own purpose, and this is what happens when ritual magic, rather than ceremonial magic, goes haywire, and backfires on the original parties of ritual magic.