You can't anchor anywhere in the City of Seattle except in a designated
area of Andrews Bay in Seward Park. There is an exception for the
Opening Day ceremonies in the Montlake Reach.

This old law dates back to the late 60's or early 70's, when a "hippie
barge" anchored off Matthews Beach park. Everytime the cops would show
up for a raid, all the contraband went overboard. Was a rather neat
arrangement. The neighbors were not amused. "Those kids have long hair!
They're listening to rock 'n roll music! A bunch of them are probably
against the war in Viet Nam! Get those damn communists off our beach!"

Somebody advised the city attorney that the only way, for sure, to get
rid of the hippie barge and prevent it just simply showing up off
another park someplace was to ban achoring in the City of Seattle. And
so the law stands today.

If you own lakeside property, you can probably get a permit to put a
permanent mooring buoy in front of your house. (These days, if you have
lakeside property, you can probably afford a boat that will require a
200 foot commercial pier). :-)

If the City of Seattle doesn't issue permits, check with the Corp of
Engineers. They control the level of the lake, etc, at the locks.
Unless you own the property immediately ashore, however, I think you're
out of luck.