Yesterday at Terra Nova there were several hundred Lesser Snow Geese (I didn't think to count), but the flock covered less of the field than it did the last time I was there, two weeks ago.
Drinking from a very full ditch.
The Richmond Snow Goose situation is fluid, changing from year to year and month to month during the non-breeding season. Numbers have increased steadily over the past several decades. This year, for whatever reasons, they did less damage to Richmond playing fields than in 2007-08, when they really overstayed their welcome. According to Campbell et al. (1990), their peak spring movement (i.e., getting a move on) is April 18. Assuming that hasn't changed much, the bulk of them should be gone in three weeks, on their way to Wrangel Island, Siberia. I'm not sure how the flocks that overwinter in Washington State and California play into this, whether they stop over or fly on past.
Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, J.M. Cooper, G.W. Kaiser and M.C.E.McNall. 1990. The Birds of British Columbia. Vol. 1. UBC Press.