The project is limited to the replacement of two culverts at EBMUD’s Aqueduct Station 330. The culverts are intended to drain stormwater away from the aqueduct right-of-way. Culvert #1 is located on the north side of Aqueduct #1 and culvert #2 is located on the south side. The current culvert configuration allows for stormwater to flow from culvert #1, meander around the bent, and eventually through culvert #2. The circuitous flow path is inefficient, causing erosion around the bent and downstream from culvert #2. A short section of the subterranean Aqueduct #2 is now exposed due to soil erosion. Culverts #1 and #2 will be replaced and extended. Work includes excavating to remove existing culvert #1, backfill with Class 2 road base, compact the
area. Excavate a new trench beginning at culvert #1’s original inlet and aligning it with culvert #2. Install two new approximately 12-inch by 24-feet high-density polyethylene (HDPE) pipes and backfill with Class 2 road base. Excavate and remove culvert #2, install either two 12-inch HDPE pipes or one 24-inch HDPE pipe approximately 35 feet long, backfill and armor pipes. Replace eroded soil on Aqueduct #2 and cover with Class 2 road base. Grade the area between culvert #1 outlet and culvert #2 inlet to direct stormwater flow between the two culverts and top with riprap.