This article shows the synergy between solar PV and the use of the canals as the location for solar canopies. They call it agrivoltaics but there is no agriculture or crops. The author said there are three benefits. But the author did not include the added benefit that the canal water keeps the solar panels cooler thus adding a small amount to their efficiency and output.
There may be some detractors. The panels need to be cleaned periodically so it may be more difficult over water, but the panels could be cleaned by automated cleaners s no human intervention is needed. Also there is plenty of water to use for cleaning.