This report was Attachment A to the 2004 Bidwell Park Vegetation Management Plan

Restoration of Chico's Riparian Habitats
(Approved by the BPPC 3/28/00)

A. Purpose of this Proposal

Due to the number of diverse groups involved locally in riparian restoration projects, it would be useful for the city to have a concept paper including specifically defined parameters and assurances of quality control to guide the efforts of volunteers or organizations with grant funds working within the city. Approval of a blanket concept paper should save time for everyone involved since projects following established guidelines could be approved with less scrutiny.

B. Project Description

Chico is fortunate to have several watercourses passing through its urban area: Big Chico Creek, Undo Channel, Little Chico Creek, Sycamore and Mud Creeks and Comanche Creek. The stream reaches through Chico serve many needs of fish and wildlife. For spring-run chinook salmon and steelhead rainbow trout they function as migratory corridors and rearing habitat. For fall and late-fall run chinook salmon and pacific lamprey they function as migratory corridor, spawning and rearing habitat. For five resident species of native, non-game fish and many aquatic invertebrates they provide complete habitat. The associated riparian strips provide habitat for a variety of wintering and resident songbirds as well as resident species of amphibians, reptiles, and mammals. Our creeks and their associated riparian strips also serve as extended laboratories for school and university students and as favorite places for relaxation, hiking and bird watching for the Chico community.

Although ornamentals have been deliberately planted in a few places, the general policy of the city has been to leave riparian corridors "natural". Unfortunately abundant seeds from nearby ornamentals have resulted in invasion by exotic plants to the point where they dominate many urban parts of the riparian strips. (See attached list of exotic plants common in Chico's riparian zones.) Native animals, particularly insects, are not adapted to feeding on the exotic plants. Consequently, exotic plants suffer little from herbivory and outcompete natives that have to produce for the herbivores as well as themselves. Riparian areas dominated by exotic plants no longer produce butterflies and other insects for bird food so diversity and interest declines.

Management plans for CSU, Chico, Bidwell Mansion State Historical Park and Chico's Bidwell Park all call for the restoration of the native riparian zone that historically occurred along our creeks. Numerous riparian sites have already been restored by public school classes or local volunteer organizations but there is much more to be done. The necessity of dealing with separate proposals for each site creates substantial work for both city personnel and the people organizing the restoration. To reduce paperwork and ensure quality control, we created this blanket proposal to cover all similar riparian restoration projects.

We propose to use volunteer labor from CSU, Chico student service organizations, the three watershed organizations, Streaminders, the Chico Unified School District (through the Watershed Education Project), and community members in replacing riparian strip exotics with native riparian plants. Public school classes will be involved wherever possible to provide kids with "hands-on" ecological education and a sense of ownership in their community.

Volunteers will be physically remove smaller exotics and replant native riparian plants. In the heart of the riparian zone, where the potential of falling limbs poses no danger, exotic trees up to a foot in diameter will be girdled and left to die and become woodpecker habitat and a source of woody debris. Exotic trees, which are larger than one-foot basal diameter or located in areas where limb drop constitutes a hazard, will be left to die naturally unless physically removed by city maintenance personnel or contracted professionals.

An exhaustive list of riparian species native to this immediate area, including all vegetative layers (ground-cover to canopy) and all stream-side zones (water-edge to top of bank) has been prepared by CSU, Chico professionals (please see attached list). When money is available, species from this list will be purchased from local nurseries specializing in native plants. Seeds and cuttings of native species will be also collected and propagated by university classes, student organizations, Chico Unified Students and the California Native Plant Society (CNPS), then used to replant cleared areas.

Restoration of the native riparian plant community will provide both immediate and long-term benefits. The immediate benefit will be hands-on education of students and local residents about ecological relationships and the techniques of restoration. Long-term benefits include:

C. Project Objectives:

  1. To replace exotic plants in Chico riparian corridors with plants native to the area, including all vegetative layers (ground-cover to canopy) and all stream-side zones (water-edge to top of bank) thereby improving habitat for fish and riparian wildlife.
  2. To create a sustainable natural riparian corridor.
    1. Native plants are adapted to local environmental variance and do not need summer irrigation; existing irrigation systems will be removed.
    2. Removal of local exotic seed sources, establishment of a native plant community and elimination of irrigation will minimize re-invasion by exotics.
    3. Continued stewardship by local residents trained while participating in the restoration process will facilitate removal of invading exotic seedlings before they become problems.
  3. To involve Chico Unified School District faculty and students, CSU, Chico faculty and students, city maintenance personnel, and community members in a hands-on, volunteer effort to restore riparian areas, thereby introducing them to the larger concept of watershed stewardship.
  4. To educate the community about the need for and process of restoration.
  5. To contribute to the ongoing effort by grassroots organizations (such as the Watershed Alliances and Streaminders) to restore local watershed ecosystems

D. Project Constraints

  1. Esthetics - A "clear-cut" devastated appearance to restoration sites will be minimized. Cleared areas will be replanted immediately to avoid the appearance of large bare areas. Girdling of exotic trees will be spaced over several years so that not all die at once and planted natives can be growing up to replace them as they die.
  2. Safety - Volunteers will be trained in safe use of hand tools. Trees that are positioned so as to have a likelihood of falling or dropping branches across trails will not be girdled (they may be taken out completely or left alone.)
  3. Erosion - Stream banks will not be denuded during the rainy season. Stream banks will be given preference for replanting to stabilize them as quickly as possible.

E. Methods

Target areas will be chosen on the basis of need for restoration, proximity to local schools, and support by local residents. Restoration in each target area will follow the sequence:

1. (Year 1-2) Enhancing existing native vegetation
  1. Obtain and rear propagules of riparian plants native to the area. Propagules of native species will be collected and raised by university classes, student organizations, Chico Unified students, the California Native Plant Society (CNPS) and local nurseries specializing in native plants.
  2. Locate existing native shrubs and patches of groundcover (Santa Barbara sedge, Woodwardia, California blackberry, mugwort, spicebush, elderberry, pipevine, buttonbush and others). Remove competing exotic groundcover and enlarge the area occupied by the native by dividing and dispersing existing plants or planting additional plants.
  3. Plant additional native groundcover and shrub plants in the general pattern of some large patches and many scattered small patches.
2. (Year 1-3) Replacing exotic trees with natives
  1. In the heart of the riparian zone, where the potential of falling limbs poses no danger, exotic trees up to a foot in diameter will be girdled and left to die. Woody debris generated by dying girdled exotics will be allowed to remain in the riparian zone or creek to provide habitat. Exotic trees, which are larger than one-foot basal diameter or located in areas where limb drop constitutes a hazard, will be left to die naturally unless physically removed by city maintenance personnel or contracted professionals.
  2. Replant with seedlings of white alder, Oregon ash, California bay, western sycamore, valley oak, and other native trees.
3. (Year 1-3) Watering
  1. a. Watering will vary with species, time of planting, and proximity to the creek, but will generally follow the pattern of twice weekly the first summer, alternate weeks the second summer, monthly the third summer, with plants expected to survive on their own after that.
4. (Year 1 and subsequent years) Landscape Integration
  1. Encourage planting of additional native shrubs and trees in lawn areas adjacent to the riparian strips to integrate them with local landscaping: Select natives such as western redbud, toyon, California rose, coffee berry, buckeye, valley oak, interior live oak, gray pine, California bay which have clear landscape qualities.
  2. Clear remaining exotic groundcover from the riparian zone and plant additional patches of natives.
5. (Year 1 and subsequent years) Maintenance
  1. a. Revisit restored areas, removing root-sprouting or seedling exotics and replanting native plants, which failed to survive. An attempt would be made to get local residents to "adopt" each target area.

F. Project Evaluation:

Photo points will be set up at the beginning of restoration in each target area. Site photographs will be taken before removal of exotics, after the initial restoration, then at the end of the first and second year.

G. Personnel

All riparian restoration projects covered under this blanket proposal will be supervised by persons approved by the Park Director.