Garden Design Ideas

This is in a small landscaping rock garden. The small rocks are on a 15′ long & 2′ wide galvanized sheet metal channel designed to direct water quickly to a front yard storm drain (or else our basement would flood). I’ll need to remove the rocks & grit by hand but it’s a small job. Grit from the driveway and dirt has caused the channel to fill up. What’s the best way to separate the grit/dirt from the rocks? What can I use that would function in effect as a colander? Thanks.

It will be a meandering pond with a small catchement area at the end where I intend to locate the pump and filter. The pond will be about 50′ long width of max 10′ and water to a depth of about 1′. The quantity of water will be about 4500 gallons
Is EPDM liner the best?
Filter capacity about 33gpm?
What filteration method? pressure filter?Bio filter? UV filter?
Pump same capacity as filter?
The pump and the filter would run in a close circuit -taking the water out of the pond and returning it to the pond.
For waterfall sperate system because the waterfall will not run very often. I will have a water fall with a breath of about 2′. Water pump 60gpm?
Again another filter for water fall system?
happy

Does any one now were i can down load any 3D drawinging plans so i can design my garden and house, they both needs lots of work.If i can down load them free all the better.