Sharon - I would be tempted to take advantage of this poor drainage and make a sort of bog garden there. Just off the top of my head I would fill a lot of it with a stony/rocky fill topped with something to stop dirt just filtering down; add dirt then plant water-loving irises etc. If you make it a dense planting any falls in to this garden will be 'cushioned' and water won't gather either. Remember - just off the top of my head so details need refining
