PHIG intern Lauren has drawn several conclusions from the data on the health of the creek. Lauren found that while the creek pH is usually in the tolerant range for aquatic life, it is often greater than ideal, which could be due to urban runoff or higher carbon dioxide levels. General hardness and carbonate have remained constantly in the desirable range.
Lauren noted that dissolved oxygen was lower than usual in 2020, even lower than a dip in 2018. High temperatures, stagnant water, and bacteria are some causes for low dissolved oxygen. She also noticed higher nitrite and nitrate levels in 2020-21, which could be caused by fertilizer runoff. Nitrite has often been above the desirable level, which could stress fish populations in the creek. Of new concern is pollution from phosphates noticed above tolerant ranges mostly at the same inlet into the creek.
Currently the creek seems healthy enough to support some smaller organisms. Minnows, tadpoles, crawdads, small fish, and a variety of birds, as documented also by Mt. Diablo Audubon Society, have found habitat in and around Grayson Creek.