[Dave] told me he had been flushing the lake with clean water, which is why it was suddenly so clear, but he agreed with me that a natural process of clearing had already begun, although the new water gave it a kick. But he added that the new sunlight in to the water will encourage algae to grow.

I have seen this on previous years where the lake is clearing in Spring but by Summer is laden with algae growths.

Or, as Marty Robbins sang:

All day I've faced a barren waste/ Without the taste of water, cool water/ Old Dan and I with throats burned dry/ And souls that cry for water/Cool, clear, water