Barrett Boesen Park in Urbandale has such a fun creek play area. The creek access is conveniently located next to the mud kitchen, so we brought some kitchen items that I purchased at Dollar Tree. My kids especially like the mixing bowls with handles along with shovels for creek play.
The only downside to creek play at Barrett Boesen is that it's popular and the area to access the creek is somewhat small, so it can get crowded. That being said, I think it's a wonderful way for kids to play and highly recommend letting your kids splash around and get muddy there.