About 150 years ago, the great Western explorer, John Wesley Powell, penned this definition of a watershed: “that area of land, a bounded hydrologic system, within which all living things are linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community.”
Watersheds are networks interconnecting “all living things” and forming co-communities of people, plants and animals.
Like nearly all human beings, we residents of San Luis Obispo County’s North Coast depend on watersheds. In these systems, whatever is added to the running water upstream can impact the network below it.
A stream flows across a landscape — runoff enters tributaries, tributaries join streams, streams flow to rivers or into ocean estuaries. There’s also vertical movement in a watershed. Precipitation percolates through the soil and subsoils to underground basins and pockets. This vertical movement rids water of materials and organisms picked up at the surface, but it also can carry pollutants into groundwater.
Watersheds are active through time as well, shape-shifting with erosion, landslides and earthquakes and the introduction of nonnative species. Climate affects watersheds, as droughts, rains and changes in climate influence water sources, soil composition, vegetation and animal habitats.
A watershed’s complex ecological relationships flourish in balance. Its health is visible in the condition of its streams and rivers. What does a healthy stream look like? Its water is clear, unless runoff is high, and varies from transparent blue to tea brown (from tree tannins). In-stream algae is vivid green and doesn’t impede flow. Stream banks are secured by networks of rocks and roots. The stream includes riffles and quiet pools for healthy fish populations. Fry can hide under downed trees and large rocks. Native insects and amphibians thrive, along with local and migratory birds. Overhanging trees provide shade that moderates water temperatures. Chemical load is low, pH levels are balanced, and biotic populations are stable.
As streams and rivers indicate watershed health, so adjacent lands determine their condition. This is where people play a crucial role. What we do where we live contribute to watershed health. We don’t have to live next to a creek to make a difference. What happens on Happy Hill or Lodge Hill doesn’t stay there. Spraying glyphosate for weed control, dumping dirty motor oil, pouring out paint thinner, even leaving cigarette butts or pet feces on the ground — all these activities can impact watershed health.
But what I spill, dump or toss dilutes, disintegrates or washes into a boundless ocean, doesn’t it? No. And as our population grows, the impact of individual actions multiplies: Algae overgrowth leads to ocean “dead zones”; popular glyphosate weed killers cause reproductive damage; chemicals and heavy metals impair drinking water wells and weaken native plants; polluted runoff affects locally grown foods.
We live together in the Santa Rosa and San Simeon watersheds — we are part of them. Let’s strive to be good neighbors to people, land, streams, forest, ocean and creatures. Their health is bound up with ours.
Want to learn more about local watersheds and support their protection? Call Greenspace at 927-2866 or visit www.greenspacecambria.org.
Wastes that harm watersheds
- Rust remover
- Paint thinner, mineral spirits
- Glyphosate weed killers
- Chemical pesticides
- Chemical fertilizers
- Gasoline, diesel, kerosene
- Motor oil and additives
- Fiberglass, plastics
- Epoxy and other glues
- Lead acid, lithium, cellphone batteries
- Prescription drugs
- Hair dyes
- Nail polish remover
- Fluorescent lights
- Oven cleaners, drain cleaners
- Toilet-bowl cleaners
- Cosmetics containing polyethylene microbeads