Don’t think there’s any sheet music of the harp parts, but Tom the harpist from the Machine is on Facebook – Tom Moth – or Twitter – @LunamothTom. He might know for sure.
What about one or more of the ‘Six Pièces’ by Jacques Ibert? They include Matin Sur L’Eau, En Barque Le Soir and Reflects Dans L’Eau, and Ballade sounds like a river, too…..