Looking good and appears a good size "what size is it roughly" cant wait to see the finished result hoping to have my own pond similar to yours sometime this year too, but will be using wooden blocks instead
The only problem doing it that way is that you cant really slope the bottom the pond towards the middle easily. Also you would need put a strainer on to stop fish going up into the filter
Looking at the design as well, notice a couple of points. The top of the filter is not level with the top of the pond (not the water level the actual pond) therefore if the pond overfils it will go over the filter system which could cause trouble later on.
Anothing this is the level of the pump. Is the pump sitting above the water level? If so then if power ever goes off then the pump could run dry when power turns back on. You are better having it under the water level so water will sit in the pump if power goes off. However this can pose some problems, if power goes off in the winter becare that the pump doesnt burst to the water freezing. Also (depending on the type of pump) it doesnt get flooded
When you are thinking about piping, it'll be worth putting in a drainage pipe idealy as low as you can so if you have to get out and you can easily.
thanks for reply points noted but my drawing skills are not too good the pump will go inside my brick filter housing alongside the filter and the top of the filter box will be the same hight as the pond wall good idea to have a drain will look at putting one in
I thought it was just down to the drawing but thought i should just make sure. Just remember that once its built and done its very hard to add stuff to it, so consider if theres anything you want to add in the future and it might be worth adding it now.