Much like Our Wives Under The Sea this is a character driven, slow burn, melancholic literary horror. I had this on my highly anticipated release list as i love a dystopian setting, and the atmosphere in this was perfect. The city is its own character and comes to life on the page. The never-ending rain, the grey, damp, and dull lives, and society fighting to build lives around crumbling foundations all matched the moody, despairing, and depressing lives of Isla, Irene and Agnes. 
As with OWUTS, you never can quite get a grip on the story or the lives of our characters. It's all very fluid with glimpses of details and a vague sense of motivation that builds to a perfect final 50 or so pages where it builds to a crescendo that still doesn't provide a whole lot of closure but does also give us some answers and clarity (albeit still pretty fluid and dreamlike).
My main wish for this book (and probably would need a companion piece) would be to have more about the city and society- the rituals, the dispersed communities and their goals to survive.
If you want straight forward you're not going to get it but if you're looking for a strong character focus and are able to read between the lines and have patience you will be rewarded.