Materials List: Erosion in Rivers

This activity was designed for classrooms with access to a 3D-printer and an erosion table. However, if either tool is unavailable, instructions are provided for alternative materials.

The class needs:

  • simulation of river flow, via an erosion table with hydraulic bench OR a stream table OR a homemade erosion table; see below for details on these options
  • small-size model buildings, one per student, made via 3D printer (plus computer and free drawing software) OR LEGO pieces; see below for details on these options
  • 10 pounds fine sand ($5)
  • water, sink and buckets
  • Erosion in Rivers Pre-Activity Quiz, one per student
  • Erosion in Rivers Post-Activity Quiz, one per student

River Simulation Options

A photograph shows a long, black plastic tray with six-inch sides filled with beige sand. At one end, a small stream of water pours in, traveling down the table through a meandering canyon in the sand.
Figure 1. An erosion table filled with fine sand.
Copyright © 2012 Ryan Cain (used with permission)

  1. Erosion table with hydraulic bench for academic purposes, such as the Hydro-Geology Stream table – Hubbard (product #Z06394M) for $1,330 from Nasco at; the recommended table dimensions are 26-in wide x 66-in long x 6-in deep; the author performed the activity using this erosion table, shown in Figure 1.
  2. Alternatively, use a stream table, such as the Stream Table Kit (product #SB01704M) for $80 at Nasco at; its heavy plastic tray is 14-in wide x 48-in long x 3-in deep with a drain hole.
  3. Alternatively, create a homemade erosion table; although a bit more work, it is an efficient low-cost alternative that can be created for ~$41 using the following supplies:
  • a large plastic box of similar dimensions to the erosion and stream tables; manually create a drain (hole) on one end; estimated cost $12
  • bucket or pan, to collect the water; estimated cost $5
  • filter, such as a piece of cheesecloth, to keep soil from escaping the pan; estimated cost $4
  • a pump, with velocity or flow meter if possible, so students can observe differences in erosion effects due to flow rate changes; estimated cost $20

Model Buildings Options

A photograph shows a big black box on a tabletop with a display screen and buttons on its front panel, and open in the front and sides to view an inside platform and machinery.
Figure 2. An example 3D printer, the MakerBot Replicator 2.
Copyright © 2012 Sophia Mercurio, Polytechnic Institute of NYU

  1. 3D printer, for example, the many models made by MakerBot Industries such as the MakerBot Replicator 2 (Figure 2; $2,000) or MakerBot Replicator Mini Compact ($1,375) at; the author used an earlier version of these 3D printers, the Thing-o-matic by Makerbot (; using any 3D printer also requires the use of computers and software, such as:
  • computer, one per student; alternatively, small groups of up to three students could work together on one computer so fewer computers are needed
  • 3D modeling drawing application, for designing building units, such as Google Sketch Up (; free) or 3D Tin (; free); helpful tips, tutorials and download information are available at
  • For design ideas and downloadable designs, use; suggested designs include and
  • a supply of the filament material the 3D printer uses to make the building models
    A composite image shows a photograph of a standard set of LEGO pieces given to each student. Arrows from this photo point to five photos, each showing a different way those pieces can be arranged to form model buildings.
    Figure 3. Using the same LEGO pieces, students create their own model buildings.
    Copyright © 2012 Sophia Mercurio, Polytechnic Institute of NYU
  1. Alternatively, give each student an identical set of 20-25 LEGO pieces (estimated cost $3), from which they can make their own unique model buildings (Figure 3); available for purchase at;%20; a suggested mix of typical LEGO pieces for a set of 19 includes the following pieces:
  • (2) 2 x 6 (one thickness)
  • (2) 4 x 8 (one thickness)
  • (2) 2 x 8 (one thickness)
  • (4) 2 x 3 (double thickness)
  • (1) 2 x 6 (double thickness)
  • (4) 1 x 8 (double thickness)
  • (4) 2 x 8 (double thickness)