Help with frog spawn

I'm in N/W England and this morning found a patch of frog spawn in a drainage ditch which drains into a grid/the sewer in my garden, what do I do with it?  I have no pond, there are no ponds nearby and the ditch will be filled in soon as it's part of drainage works happening in my garden.  I read this normally happens in early Spring but it's currently the end of September!  Any advice? Should I relocated it?