The inlet of a greywater wetland can be trouble if you don't plan carefully.  This is where the most tasty (from a dog's point of view) gunk is going to land, so you want to close it in to prevent nibbling.  Water will also be gushing out of the pipes with quite a bit of force here, so it's handy to make a solid bottom in this area to prevent erosion.

There are lots of designs for greywater inlets, but I wanted to work with what I have on hand --- bricks from the old chimney.  I loaded up a wheelbarrow full of the best ones and brought them down to my budding wetland.

The pipes aren't in place yet, but they'll be bringing water in from the top-left side of the picture above.  I simply laid bricks loosely on the ground and put a few on the downhill side to further break up the flow.

I'd been saving these fire bricks since they hold their shape much better in freezing, wet conditions than the bricks that made up the bulk of the chimney.  I assume "Davis Savage," which is stamped on each fire brick, refers to some long-ago local brick manufacturer.  I only had enough fire bricks to coat the bottom of the inlet, but that'll probably be the spot that stays wet longest and will need to be strongest.

Some river rocks laid loosely on top may or may not be enough to keep Lucy out.  We'll have to wait and see.  I can hardly wait until these bricks moss over and the greywater trickles down them like a tiny waterfall.

(Can you tell building the greywater wetland is the most fun I've had all year?)