Healthy streams need an intact riparian canopy, well-vegetated soils, and large trees alongside the stream banks. Photo by Jodi Frediani

by Jodi Frediani

We all know that hardening of the arteries is damaging to human health and that arterial blockages can lead to death. We also know that toxic substances in the bloodstream can cause cancer and other serious problems. Not surprisingly, our streams and rivers —the circulatory system of our environment— must be protected from similar threats.

We need to treat our creeks and streams as the lifeblood of our environment and not as drainage ditches. Taking better care of our streams is not only good for us and our drinking water, but essential for several local threatened or endangered species—coho salmon, steelhead trout, and California red-legged frogs.

What do healthy streams need?
Healthy streams need an intact riparian canopy to keep water cool for fish. Creeks and rivers need “breathing room”— well-vegetated soils for proper infiltration of rain. Riparian corridors should be kept free of development and impervious surfaces. Large trees along creek banks should be retained for canopy and their strong root systems which stabilize stream banks, retard erosion, and, where exposed, provide hiding places for fish. When such trees fall into the creek, the downed logs help regulate the flow of water and sediment downstream and continue to provide essential cover for fish. Downed wood also helps create deep cool-water pools needed by fish.

Development along stream banks can result in an unhealthy waterway. When we allow buildings in the natural stream flood plain or along stream banks, for example, we create problems. Flooding is a natural stream process which replenishes soil nutrients. A better use of flood plains and banks is for parks and greenways which can be flooded occasionally without threatening homes and businesses.

What harms waterways?
Dams and culverts restrict water flow and impede fish passage. Excessive sediment generated from dirt roads, landslides and bank erosion clogs spawning gravels and reduces survival of hatching fish. Organic matter which accompanies sediment entering streams interacts with chlorinating products to produce cancer-causing compounds in drinking water.

Excessive logging or cutting of trees along a stream bank eliminates the leafy canopy which shades the water and provides fish habitat. An extreme example of canopy removal is the clearcutting of trees within the channel of the Pajaro River after the floods of 1995. The levees constrain the natural flood waters, turning the river into a flood control channel. The trees, which provided many functions including significant bird habitat, were considered a threat because they took up room in the flood channel.

Channelization (straightening of the stream course) increases the velocity of the water as it runs downstream. An extreme example is the channelization of Branciforte Creek where it flows into the San Lorenzo River (also channelized between levees) in Santa Cruz. Less extreme channelization techniques are applied to protect poorly-sited houses and roads adjacent to creeks and streams. Such retaining walls restrict or change natural flows, do not provide useful habitat, and otherwise degrade the health of the waterway. It would be better to enforce existing setbacks from the riparian corridor and establish appropriate setbacks in communities where there are none.

Storm drains laden with oil, tire dust, and other road pollutants are directed to creeks and ultimately the Monterey Bay National Marine Sanctuary. Instead, we should be capturing this runoff on land and letting it filter through constructed wetlands and soil before naturally flowing to the water table or into streams once adequately filtered. This can be accomplished in many ways including constructing French drains, using permeable surfaces for driveways and sidewalks, and directing runoff toward green areas for biofiltration instead of directly into storm drains.

Additionally, creeks and rivers are polluted from leaking septic tanks, sewage leaks, farm and garden pesticides and poorly maintained dirt roads. Most of our local streams and rivers are listed as impaired for sediment under the Clean Water Act, and some are also adversely impacted by pesticides, septic runoff and other pollutants.

The National Marine Fisheries Service (NMFS) will be releasing their draft Coho Recovery Plan in early 2009. This plan identifies a number of areas where Santa Cruz County riparian policies are deficient and detrimental to the survival of our nearly extinct coho salmon populations. These policies are in need of a major overhaul. For years, the County has been removing fallen trees from stream channels often at the request of concerned landowners. NMFS wants those trees to remain. Property owners need to be educated about the importance of these essential elements in a healthy stream system. More culverts need to be retrofitted for fish passage or better yet, replaced by bridges to allow fish into currently inaccessible stream reaches. New construction should be kept out of riparian corridors to limit septic leakage and input of pesticides, herbicides and household chemicals.

Poor policies and enforcement
Santa Cruz County has a history of granting riparian exceptions, allowing for additions to existing non-conforming structures within the 50’ riparian buffer zone. A recent project proposes reducing the riparian setback from 50’ to 20’ along Aptos Creek and running storm water culverts directly into Aptos Creek for a Planned Unit Development. Another project redirects flows into Rodeo Gulch by building 1500' of new drainage pipe and bypassing a wetlands. Rather than removing culverts as Berkeley is doing (a process called “day-lighting”), Santa Cruz County is creating more runoff into more drainage ditches and installing more culverts.

It took two months of complaints before the County red-tagged this illegal cistern in a coho stream in Bonny Doon.

Code enforcement needs to take stream protection seriously as well. When an illegal concrete cistern was constructed recently in a tributary of Laguna Creek in Bonny Doon, a coho stream, it took two months of complaints from multiple neighbors including photographs circulated far and wide before the County red-tagged the structure. At press time the partially-dismantled cistern was still in place and causing bank erosion and water-quality degradation. If removal is not done in a timely fashion, the county road adjacent to this cistern could actually fail, sending tons of soil into the creek channel.

Often the need for affordable housing is cited as a reason to allow building in riparian corridors. Housing is an important need, and it must be sited in less environmentally-sensitive areas. It harms everyone to build in areas prone to flooding, most especially the residents themselves.

We need to learn to respect our local creeks and rivers and remember that they all flow into the Monterey Bay National Marine Sanctuary. Our creeks and rivers are the lifeblood of our communities.

< back to all issues