Can I Build On A Slight Slope

[Daniel12490]

Hi All,

It’s been sometime since I’ve posted and finally made a LOT of progress but need help in getting this pond over the finish line by spring of 2026.

So, my pond depth is 4 feet with one 18 inch shelf. I live in a pretty rural area so predators are abundant. I’m hoping with the four foot depth and a cave or two, my koi will be well protected. I’m also planning to use the shelf for plantings as my backyard dosent have a whole lot of shade.

My question is as follows, how do I cut in correctly for my waterfall for filter return? I’m planning on using a skimmer directly across from the waterfall to maximize cleaning and circulation. I don’t know much about pond filtration so what are my options? Do I need a bottom drain?

Attaching some pond build photos!

 

[GBBUDD]

Looks like you have been working hard. But your statement about abundance of predators and only having an 18 deep shelf could be problematic if you really expect the blue herons in particular then I would shoot for a 30 inch shelf..
90 % of the flowering bog and marginal plants that is have found just like there feet wet . 18 inches deep other than pickrel weed lilies they are they only two that can thrive in 18 inches of water. Unfortunately so can the great blue bird . They can wade in 24 inches of water. Walk in the pond and wait for a fish to swim by.
There's only two sure ways to protect your fish. One net and cables over the pond. That and having a 30 inch drop from. The edge of the pond to the water line that is vertical or so steep the dang birds can't stand on the edge. Or wade on the water. So my answer to your question as to plants. get your liner over sized and just make some 1 foot deep areas along the side of the pond and let the plants thrive there. And give the fish their security with no where for the birds to walk . Trust me lilies will fill the surface of the pond you'll be glad you gave more surface area to the design