How Do Forests Play a Role in Our Water Story?

The U.S. Forest Service within the Santa Ana River Watershed is currently managing two forests: San Bernardino National Forest and Cleveland National Forest. The two combined encompass 29 percent (1.1 million acres) of the Santa Ana Watershed’s land mass. This land mass is mostly comprised of trees, meadows, and chaparral, which all provide advantages and disadvantages. Though only covering about a third of the watershed in area, this same forest area within the watershed receives over 90 percent of total annual precipitation and directly impacts the amount of water and water quality downstream. Too many trees will decrease the water supply causing a greater risk of forest fires. On the other hand, they are a natural filtration system against sediment, fertilizer and pesticides from agricultural and urban runoffs. In addition, during heavy rainfall and snow melt, they soak up excess water helping to minimize floods. Meadows are nature’s sponge in that they retain large amounts of water for groundwater recharge. Besides trees, the other major type of vegetation is chaparral which is predominantly closer to the foot of the mountains is also beneficial against erosion control and water dispersion, but is simultaneously prone to becoming fire fuel. Because of the sheer amount of land in the watershed, it has become increasingly challenging for the U.S. Forest Service to maintain, as well as address other problems that may arise from droughts including pine bark beetle infestation, and increased risk of human-initiated forest fires.