ITEM: |
INFORMATIONAL ITEMS/STAFF REPORTS |
||
|
|||
30. |
QUARTERLY CARMEL RIVER EROSION
PROTECTION AND RESTORATION PROJECTS REPORT |
||
|
|||
Meeting Date: |
July 19, 2004 |
Budgeted: N/A |
|
|
|||
Staff Contact: |
Larry Hampson |
Program/Line Item No.:
N/A |
|
|
|
Cost Estimate:
N/A |
|
|
|||
General Counsel Approval: N/A |
|||
Committee Recommendation: N/A |
|||
CEQA Compliance:
N/A |
|||
Carmel River Large Wood Inventory: During the summer and fall of 2003, a survey of large wood in the channel bottom was completed between the Carmel River lagoon and San Clemente Dam. The Watershed Institute at California State University Monterey Bay, the District’s contractor for the work, completed the final report in June 2004. Essential findings from the report include:
• A comprehensive survey was completed
along 14 miles of the Carmel River. In this section of river there are 471
occurrences of large wood (LW) or LW accumulations. This figure leads to an
average frequency of nearly 37 significant LW pieces or accumulations per mile
of river.
• The density is not evenly distributed,
but decreases downstream and is highly variable.
• Approximately 71% of LW pieces are
between six and 12 inches in diameter. About 84% of the wood is between five
and 20 feet in length. There is an increase in LW size downstream from Via
Mallorca.
• 70% of the LW in the Carmel River has
no significant impact lateral channel stability, or is protecting the banks
from erosion. Only 3% of the wood was causing bank erosion.
• 29% of the wood was fostering pool
habitat in the bed.
• 50% of the occurrences of wood were
associated with aquatic fauna sightings, commonly with multiple taxa (species)
per sighting. Fauna included steelhead trout, stickleback, crayfish, western
pond turtles, California red-legged frogs, and bullfrogs.
• 7% (35 pieces) of the LW surveyed in
2003 had been placed in the stream for habitat enhancement purposes by MPWMD.
The final report is
currently available over the Internet at:
http://science.csumb.edu/~watershed/pubs/carmel_lwd_2003_report_fina.pdf
In the past, much large wood in the channel bottom
was routinely removed or modified (cut) with the assumption that this action
would reduce the potential for bank erosion and/or damage to public
infrastructure. This type of management
is no longer allowed in the Carmel River, as large wood can provide significant
habitat for aquatic species and alteration of streamside habitat is closely
regulated. MPWMD
developed and has implemented guidelines for managing large wood that provide a balance
between habitat preservation and protection of public and private property.
It appears that the vast majority of large wood
and debris currently in the system is not inducing erosion. However, it is clear that large
accumulations of wood and debris during high flows can cause bank erosion and
bridge failures. It is likely that
live, fallen trees washed out from streambanks during high flows add
significantly to woody debris accumulations.
Carmel River Violation: A serious violation of the District's riparian ordinances occurred in
late December 2003 on two residential properties on the north bank of the
river just upstream of the Rancho Cañada Golf Club. One of the property
owners, Roy Woods, had directed workers to cut riparian vegetation and place
concrete slurry on the river bank in an area that had been armored with rip-rap
following the high flows in 1998. Approximately one-half of the work was
carried out on an adjacent property, owned by Nick and Gerda Marotta. District staff took enforcement action against
both property owners and recorded Notices of Non-Compliance on the titles of
both properties.
Carmel River Watershed Council (CRWC) Coordination: MPWMD continued work on an assessment of biologic, aquatic, and environmental conditions along the main stem. A draft report was completed in early July that staff is reviewing for consistency. A final report is expected to be completed by early August 2004.
U.S. Army Corps of Engineers
(Corps) Permit for Carmel River Activities: The District received the final,
signed Regional General Permit (RGP) from the Corps to carry out Mitigation
Program projects along the Carmel River, valid through October 30,
2009. The permit also allows riverfront property owners to
conduct work on their property, as long as they agree to conform to the conditions
of the permit. The permit includes by reference three lengthy
documents that provide detailed direction on activities allowed by the permit
and measures required to protect steelhead and California red-legged frogs.
Staff estimates that the cost since 1999 for obtaining the permit was approximately $111,000, which consisted of $32,000 in consultant-related costs and $79,000 in staff costs. The permit is expected to significantly reduce the administrative costs and time required to obtain specific project authorizations over the next five and a half years.
Annual Carmel River Inspections: District
staff continued the annual inspections of the Carmel River from the
upstream end of the lagoon at River Mile (RM) 0.5 to Camp Steffani at RM
15.5. Staff members responsible for vegetation management and erosion
prevention annually walk the entire river to observe and record erosion damage,
conditions that could cause erosion (e.g., in-channel vegetation or debris),
riparian ordinance infractions, presence of deleterious material, and the
overall condition of the riparian corridor. Staff also uses these
inspections to document existing river restoration projects and compliance with
previously issued River Work Permits.
Staff has completed an inspection from Camp Steffani to Rancho Cañada. Several riparian ordinance infractions were noted, and staff plans to follow up on these with letters to individual property owners. Overall, most of the river between Camp Steffani and Schulte Road Bridge appears to be healthy, with a few isolated areas of bank erosion. However, staff noted several locations where vegetation encroachment into the center of the channel appears to be extensive enough to increase the potential for bank erosion during high winter flows. Additional work to document these sites and develop a modification strategy is under way.
The most heavily pumped reach during the dry season, between
Schulte Road Bridge and Rancho
Cañada, continues to show signs of plant stress in some of the areas without
active irrigation programs. Most
streamside areas within this reach that were restored by MPWMD and private
property owners since the floods of 1995 and 1998 appear to be fairly healthy
and stable and are benefiting from regular irrigation during the dry season. However, bank loss continues in some areas
previously damaged by winter flows and that are not irrigated, especially
between the vicinities of Rancho San Carlos Road Bridge and Via Mallorca
Bridge.
U:\staff\word\boardpacket\2004\2004boardpacket\20040719\InfoItems_Reports\30\item30.doc