Written by Alyssa Burley.
RCP Block & Brick is a concrete masonry and hardscape supplier. The company mined sand from the San Diego River in order to manufacture concrete blocks used in local construction projects (e.g., hospitals, parking structures, schools, homes and community centers).
Students toured the facility and saw first-hand how concrete blocks are made. Tom Phelps from RCP Block & Brick noted the blocks used to build the elephant enclosure at the San Diego Zoo came from the Santee plant and were made with sand mined from the San Diego River.
While at the plant, the students performed a sieve analysis to determine which sample of sand is best for making concrete (i.e., river or beach sand). Then, they mixed their own concrete using sand, gravel, cement and water. Instead of making concrete blocks, each student choose a fun silicon mold to use. Some chose footballs, butterflies and trucks. At the end of field trip each student were able to take their concrete projects home.
Walker Preserve was created by removing sand from the San Diego River bottom. The sand was used to make building materials. The voids that were left from the sand removal were turned in to several ponds. The ponds provide a water source for local wildlife and pleasant views for residents. The site’s reclamation plan transformed the formerly dry river bed into a rich nature preserve.
The students toured the trail and learned about the area's former use as a sand mine and the reclamation project designed to establish native vegetation along the slopes.
The City of Santee built the trail that runs along the northern edge of the preserve. It is open to the public for walking, equestrian riding and biking.
Photos by Alyssa Burley.