Dear Keith,
This is a note of appreciation for creating a lovely, tranquil environment in our backyard. Ever since you built our pond, we have enjoyed watching our fish, listening to the peaceful flow of water and relaxing by the pond. In what was once an unattractive dead spot in our backyard, the pond is now a natural beauty and the focus of all our outside activities.
We have always enjoyed our backyard during the summer months, but now we will also enjoy its beauty during the rest of the year.
Thank you for creating this lovely environment.