"where people drown in lakes"
Public DomainRhododendrons

Even in her champagne-infused state, Bridget's literary credentials shine through.  Rhododendrons are mentioned in D.H. Lawrence's 1915 novel, The Rainbow:

Maggie's people, the Schofields, lived in the large gardener's cottage, that was half a farm, behind Belcote Hall... In the morning, a covering of snow weighed on the rhododendron bushes.

In 1920 the sequel, Women in Love, was published. It focuses on the third generation of the Brangwen family chronicled in The Rainbow, sisters Ursula and Gudrun. Gudrun has a relationship with Gerald, heir to an impressive estate.  On it is a lake in which his sister drowns.