EXHIBIT 2-A
Scope of Work, Budget and Schedule
Most
of the riverbed and streambanks along the alluvial section (the lower 18 miles)
of the
The material carried down from the
upper watershed makes up the water-bearing alluvium in Carmel Valley that is
pumped to supply Cal-Am and non-Cal-Am demand.
Because the river channel changes in response to the amount of sediment
that flows through it, an important aspect of managing and understanding this
portion of the riparian corridor is long-term monitoring and documentation of
changes in the elevation of the river bottom.
Gravel mining, main stem reservoirs,
and streambank armoring have contributed to a sediment-starved condition in the
river channel downstream of Los Padres Dam, which is located at approximately
River Mile (RM, measured from the ocean) 25.
A chronic lack of sediment from the watershed area above San Clemente
Dam for 95 years has been a factor in aquatic habitat degradation, channel
incision, streambank instability, infrastructure damage, loss of property, and
episodes of bank erosion along the river.
In addition, incision and removal of alluvial valley deposits reduces
the volume of water that can be retained in storage in the Carmel Valley
Alluvial Aquifer.
One
of the results of sediment starvation in the alluvial reach is that in-channel
supports for basic infrastructure (bridges with roads and utilities) have been undermined
and compromised at several locations. In
addition, there are areas along the river where scour at the base of slope
protection installed to prevent bank erosion has caused bank slumping and/or
the protection appears to be at risk of failure during high flows.
The
focus of the work proposed in this scope will be to gather thalweg (low point
in the channel) data between the Carmel River lagoon and Carmel Valley Village for
use in maintaining a long-term record and to compare to past and future monitoring
data. Comparisons of repeated surveys
carried out over long periods can yield information about the long-term rate of
aggradation (i.e., sediment build-up) or degradation (i.e., loss of sediment),
effects of restoration projects along the river, and can inform decisions about
infrastructure maintenance and repairs and proposed restoration projects.
Survey
data will be used by MPWMD staff to adjust Carmel Valley Alluvial Aquifer
parameters and to monitor effects to downstream areas from ongoing sediment
retention at San Clemente and Los Padres Reservoirs.
It
should be noted that San Clemente Dam at RM 18.6 will be removed in 2015. The dam no longer traps 100% of the bedload sediment
(the portion of the sediment load that tends to roll or saltate) and currently,
fine grained material can move past the dam at high flows. After the dam is removed, it is likely that
in addition to fine-grained material, coarse-grained material will begin to
move past the dam in the foreseeable future.
Thalweg profiles are one of the key monitoring methods in evaluating the
effects on the streamside corridor from any increase in sediment flow. A potential change in sediment flow to the
lower 15.5 miles is also an issue that must be evaluated with any alternative
associated with long-term management of Los Padres Dam and Reservoir.
Previous MPWMD Survey Work
MPWMD
conducted the first detailed long profile thalweg survey (a survey of the
lowest point along the channel) of the lower 15.5 miles of the
In
1995, MPWMD contracted with Central Coast Surveyors to set 12 permanent survey control
points in the vicinity of six different bridge locations[1]. The bridges are located along the river as
shown below. The control points were set
using Global Positioning System receivers and referenced to a control point in
the CALTRANS High Precision Geodetic Network.
These control points can serve as intermediate check points for surveys
along the river.
Bridge ___ Owner[2] ___ RM[3] Comment
Via Mallorca Hacienda Carmel 3.24 Two-lane bridge.
Valley Greens MCPWD 4.82 Two-lane bridge
Don Juan MPRPD 10.78 One-lane bridge
Rosie’s MCPWD 14.45 Two-lane bridge
It
should be noted that due to limited access into the riverbed, gathering
detailed survey work along the channel bottom may involve long hikes in
difficult terrain. If the riverbed is
dry at the time a survey is performed, MPWMD will grant access into the
riverbed near
Approach and Scope of Work
Tasks
and the percentage of the budget to be used for each task are shown below. MPWMD staff is requesting that up to $25,000
be made available for this work. The
portion of the budget to be used for each task is approximate and is intended
to be a guide in carrying out tasks. The
percentages shown may be modified based on field conditions and/or
recommendations made by the Consultant for the work.
Task 1 (85%) – Obtain Long Profile.
Gather thalweg data along the bottom of the river channel
between the upstream end of the
Profile
data shall be provided as a spatially referenced file (NAD 1983 and NAVD 1988) and in drawings at a horizontal scale
of 1 inch = 200 feet and a vertical scale of 1 inch = five feet (all drawings
no larger than 24 in. x 36 in.). Data should
be in an Excel format, similar to previous thalweg profiles, with an ability to
import new data into existing data files. Drawings may be in PDF format.
Task 5 (15%) – Prepare Report. A report shall
be prepared that presents results and describes the equipment and methods used
to gather and analyze data.
Project Deliverables:
Any
reference articles, books, publications, or software purchased specifically for
this study shall be provided to MPWMD.
Data input and output files from computer analysis shall be
provided. A final report shall be
provided in an acceptable digital format (e.g., Word, PDF, Excel). All files are to be provided electronically.
Budget:
It
should be noted that the scope of Tasks 1 and 2 may be amended in order to
maintain project costs within the proposed budget.
Professional
Services
Up to $25,000 to be expended
on a time-and-materials basis. Expenses
are estimated at $2,800 per mile of channel surveyed (includes analysis and
report delivery).
Schedule:
It
is anticipated that survey work would commence soon after issuance of a notice
to proceed (i.e. during late August or early September 2014). All filed work shall
be completed within four months of authorization to proceed and the project
shall be completed within six months of authorization to proceed.
U:\staff\Boardpacket\2014\20140818\ConsentClndr\02\item2_exh2a.docx
[1].
MPWMD, May 20, 1995. Survey Control
Points Established with GPS Methods,
[2]. Owner or responsible agency. MCPWD = Monterey County Public Works Department, MPRPD = Monterey Peninsula Regional Park District
[3] RM = River Mile, measured from the ocean along the approximate center of the channel