On 25/08/2019 20:19, Dave Liquorice wrote:
On Sun, 25 Aug 2019 05:50:00 -0700 (PDT),
wrote:

If you block up the outlet completely it becomes a cesspit and does not
discharge into the watercourse.

The OP says it's draining into drainage field that is now blocked.
It's not drianing directly into a water course. So the 1st Jan 2020
compliance doesn't apply.

Just replace the drainage field. But with seven other housholds all
sharing it getting everyone to agree to share the cost, how much to
spend and then stumpup the dosh is another matter. Who said move?
It's simpler...

A higher water table doesn't necessarly mean that the drainage is any
less than it was before. Water does move downhill through the ground.

I was dubious about that claim too. There's a standard meme about
someone digging a ditch at the bottom of a sloping field to improve
drainage. You should normally dig the ditch at the top, to intercept
run-off *into* the field.