This gist of it is that Hydro turbines do not need to be approved under the Microgeneration Certification Scheme (MCS) but can get access to FiTs via the ROO-FIT process via Offgem.
“the Department for Energy and Climate Change (DECC) published their intention to extend the ROO-FIT accreditation process for micro-hydro installations indefinitely… hydro installations with a DNC of 50kW or less must continue to be accredited for the FIT scheme under the ROO-FIT accreditation process. This process is administered by Ofgem. Therefore all hydro installations with a total installed capacity up to and including 5MW will continue to be accredited through the ROO-FIT process, from 1 October 2012 onwards… contact the Renewable & CHP team at firstname.lastname@example.org.”
I have two Powerspout customers pursuing this ROO-FIT thingy now, and both of them happen to have wordpress sites as well: