Preventing Agricultural Water Pollution

The West side of the San Joaquin Valley represents a perfect storm of environmental unsustainability, combining massive Delta diversions, poor drainage conditions for agriculture and contaminated runoff.

Here, the largest irrigation district in the country and other water users import huge amounts of Delta water – harming aquatic species and their habitats in the process – which are applied to drainage problem areas with high levels of selenium and other toxic trace elements in the soils. The subsurface runoff has contaminated drainage ponds, the local aquifer and the San Joaquin River, even killing and deforming waterbirds in the worst cases.

Over the years, The Bay Institute has fought to halt completion of the partially-built San Luis Drain, which would convey the West side’s polluted drainwater to the Bay-Delta, and close contaminated evaporation ponds throughout the San Joaquin Valley. Instead of transferring the drainage problem to other areas, the best solution is the "4 Rs" approach:
  • Retire the worst drainage problem areas from irrigation

  • Reduce the volume of drainage produced by using source control and other methods

  • Reuse and manage residual drainage where it is produced

  • Reclaim salts and other materials at the end of the waste stream

The Rivers & Delta program works to promote the 4 Rs approach as the basis for future management in our ongoing battle to win an environmentally sound solution to the West side drainage problem.