Another interesting subject then would be how they use data from past flood events such as flow and depth to map out flood risk areas. The models themselves cost in the region of £30/40k as they're usually done externally.
I'll PM you as I've got a book on what is basically river rehabilitation, so in times past when a rivers course was in the way, they would pretty much build a new water course to divert it, or in the case of towns and cities, they would culvert a lot of a river and make it mechanical pretty much.
Being geeky I followed a few schemes that were / are being done. The Jubilee River near London way is amusing as an engineering botch up, as by creating a diversion a bit like a balancing pond, but not a balancing pond, they created a whole new flood risk that never existed. Cities like Birmingham have the River Rea, where the majority of the time it's a trickle, but during storms can be 15ft in depth. That's a mechanical channel with tall buildings either side. The bed is actual concrete, so little opportunities for biodiversity. In Birmingham there's an old factory that was used for building industrial units and homes. They opened up the culvert, or proposed to, rehabilitating the river to a more natural environment.
A lot of the engineers who had the idea you could make water run where you want, discovered that you had to pretty much use concrete in order to do this.
Another area of interest you could really get into is how there was/is legislation under a document Making Space for Water, so areas that typically flooded, you wouldn't build on, but some how such developments get the goahead. There's no such thing of creating defences in one area and the problem is solved, you need intense engineering to ensure you don't push the water elsewhere, creating a new flood risk.
Cumbria / Lake District is quite interesting, as is Cornwall/Devon. More so the later plus East Coast as it's tidal, so if you get a centralised storm with spring tides you have a nightmare on your hands.
If nature / biodiversity / geomorphology is an interest, from the Bristol Channel down is geologically interesting due to how the sea/rivers affect the land with say salt marshes, mud flats. How they're developed. How the rock in the area can play a big role, where to go fossil hunting etc. Boscastle is a good example, how a simple storm can cause havoc.
Sorry it's an area of interest if you can't tell.
It's an industry that is worth millions.
Things like building defences, how bunds work, how that wall that protects an area can be so much more than a wall. So piling is needed depending on soil type. Same with constructing near to water courses. The water table. The difference between salt water and fresh water. On the River Severn & Trent you see a phenomenon where at certain times of the year you get tidal bores, people surfing up stream.
I'll stop there in case I'm boring you.