Lake Mead

While looking around along some earlier trip, I discoverd that Lake Mead http://www.openstreetmap.org/browse/relation/1275469
at some places extends far beyond the water line visible in BING.

Of course, the water level in Lake Mead changes over time, but at some places there seem to be permanent buildings (solar powerplant?) within the “Lake”
http://www.openstreetmap.org/?lat=36.07026&lon=-114.80529&zoom=16&layers=M

At other places there are fractions of ways that follow the visible coast line :http://www.openstreetmap.org/browse/way/169248440

What is to be done ?