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Levee and Revetment Routine Maintenance
Levee and revetment monitoring and maintenance
activities include:
Mowing
Some levee and revetment access roads and slopes are mowed to
allow crews to inspect these facilities during and after flood
events. This mowing is generally done in the late fall, just
before the winter flood season.
Access Control and Maintenance
Gates and gravel roads are maintained on most river facilities.
Access road resurfacing is rare, and is usually accomplished
in conjunction with a major maintenance project. Gates that limit
public access to river facilities are occasionally repaired or
replaced.
Control of Invasive Plant Species at
Project Sites
In order to improve the success of bioengineered facility repairs,
comply with state noxious weed regulations, and in some cases,
meet specific permit requirements, invasive species are removed
from project repair sites and areas where listed noxious weeds
are present. The species most commonly encountered include Blackberries,
Japanese and/or Giant Knotweed, Knapweed, Tansey, and Scot's
Broom. In most cases weeding has been accomplished through hand
labor, however in limited cases herbicides are used. A licensed
technician does all of the herbicide application.
Irrigation
In order to improve the success of bioengineered facility repairs,
most projects are irrigated weekly during summer and early fall
for two years after the completion of each project. A one or
two person crew typically does the irrigation using a gasoline-powered
pump to withdrawal water from the river. The pump intake is screened
in accordance with WDFW standards and all withdrawals are documented
per a water withdrawal permit issued by the Washington State
Department of Ecology.
Revegetation
Annual inspection of recent facility repair sites is used to
determine revegetation needs. Revegetation is accomplished by
hand crews and typically involves transplanting native species
from one- or two-gallon pots. Revegetation needs are identified
in late summer and planting occurs in the fall or winter.
Hazardous Tree Removal
Trees do occasionally fall across access roads or pose a threat
to those using the roads. These trees are either removed entirely,
or moved to the riverward side of the facility.
Facility Inventory and Assessments
Levees and revetments are inspected on a regular basis. Routine
facility assessments help identify and prioritize maintenance
needs.
Logjam Removal
Logjams are removed only if they pose a direct threat to certain
types of property, and can be removed without endangering personnel
or equipment. When logjams are moved, the woody debris is usually
dislodged and but back into the river. |
