James Serra explains why you might want multiple data lakes in an organization:
A question I get asked frequently from customers when discussing Data lake architecture is “Should I use one data lake for all my data, or multiple lakes?”. Ideally, you would use just one data lake, but I have seen many valid use cases where customers are using multiple data lakes. Here are some of those reasons:
I’d quibble with a couple of these (and given James’s intro, I’m not sure he’s fully on board with all of the reasons) but this is a good list of reasons why you might see several data lakes in an organization.