By HEATHER HACKING – Staff Writer Chico Enterprise-Record
CHICO — Cruising along Highway 99 as the freeway passes the Chapman neighborhood, often a warm stench rises from the east.
The odor is sometimes earthy, like compost; other times it’s more offensive, like the waning scent of a sewage detention pond.
The source is eutrophication, which occurs at Teichert Ponds during the warmer months. The 40 acres of habitat and water is to the east of the highway, south of Little Chico Creek and Humboldt Road.
The land was an alluvial fan, which means streams slowed down and sand and gravel were deposited over time. In the 1960s, the Teichert Construction Co. used the land as a gravel quarry for use in construction of the highway, explained Dick Cory of the Teichert Ponds Restoration Foundation.
One pond is uniformly 10 feet deep, which makes it the deepest of the three, yet the smallest in circumference.
The other two ponds are three and a half feet deep in the wet season, and drop by about half during other parts of the year.
In 1980, the city diverted two storm drains, which run through 54-inch pipes, into the ponds, rather than directly into Little Chico Creek, Cory said.
The presence of the ponds helps with flood control, and has become an area where wildlife thrives.
The water draining from the more than 400 acres of housing development nearby and into the foothills now causes the ponds to hold water year-round, Cory explained.
This brings in excess nutrients — nitrates and phosphates, which cause plants to grow quickly.
When the water level drops, the water stagnates. Then the summer plant growth dies and rots. It’s essentially pond scum.
Also, the excess plants on the surface cut off photosynthesis of plants under the water.
Some of the main plants include green and brown algae, parrots feather and elodea. Elodea is the plant you see in the bottom of aquariums, Cory explained.
Many years ago, the ponds were stocked with catfish, bass and mosquito fish. When the plants in the pond die, some fish will go “belly up” from lack of oxygen, he said.
But most fish survive and some people are known to fish the waters, he said. Yet, he said he personally wouldn’t eat fish caught there, because he knows there are so many nitrates and phosphates from nearby runoff.
Often gasoline can be seen floating at the top of the pond, from runoff from parking lots, he explained.
The longer-term plans for the area include draining one of the shallower ponds, then using the other shallow pond for flushing water, then alternating draining and flushing.
If funding becomes available, the stagnation and smell should disappear.
“If we can restore it back to what it was before 1980, the quality of the water would increase.”
For the most part, Cory said the neighbors like having the ponds nearby. Over the years, one housing developer built paths, which are used by people who take wildlife strolls.
Animals spotted in the area include wood ducks, Canada geese, songbirds, raptors, red-shouldered hawks, beavers, western pond turtles, dragonflies and many others.