From Ben's twitter account

If you're into the Saint-Venant equations, there's a new derivation in town.

https://doi.org/10.5194/hess-23-1281-2019 …

Conservative finite-volume forms of the Saint-Venant equations for hydrology and urban drainage
Ben R. Hodges
National Center for Infrastructure Modeling and Management, University of Texas at Austin, Austin, Texas, USA
Received: 02 May 2018 – Discussion started: 25 Jun 2018 – Revised: 04 Jan 2019 – Accepted: 19 Feb 2019 – Published: 07 Mar 2019