Steampunk styled self-readjusting stream table
Name ideas:

Streamoscope

Readjusting

Reconfigurable

Recombining

Miniature

Stream

River

Simulator

Cabinet

Scope

The idea is to build a stream table in a small frame (30x40x50 cm), which can reconfigure its ground support itself. It should use lightweight plastic grains for sand particles, so that features form in scale (heavier sand will not form as meandering rivers for example). Different sized particles should be different colors, to bring forth the formation shapes clearly.
Problems:

Source of finegrained plastic particles.

Plumbing

Bottom material

Solutions

Use coffee grinder to grind plastic granules to desired size

Needed things

Coffee grinder - China/ebay cheapo thing maybe

Plastic granules of some lightweight plastics

Could use acrylic waste from laser cutter, acrylic has a suitable density of 1.2

Meshes of different sizes for filtering sand particles

Pumps and valves