ITEM: |
INFORMATIONAL
ITEM/STAFF REPORT |
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24. |
QUARTERLY CARMEL RIVER RIPARIAN CORRIDOR
MANAGEMENT PROGRAM REPORT |
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Meeting Date: |
October 19, 2020 |
Budgeted: |
N/A |
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From: |
Dave Stoldt, |
Program/ |
N/A |
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General Manager |
Line Item No.: |
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Prepared By: |
Thomas Christensen |
Cost Estimate: |
N/A |
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General Counsel Review: N/A |
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Committee Recommendation: N/A |
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CEQA
Compliance: This
action does not constitute a project as defined by the California
Environmental Quality Act Guidelines Section 15378. |
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IRRIGATION
OF RIPARIAN VEGETATION: The
supplemental watering of riparian restoration plantings is currently being
carried out for the summer season at seven Monterey Peninsula Water Management
District (District) riparian habitat restoration sites. The following irrigation systems were in use May
through September: Sleepy Hollow, deDampierre, Trail and Saddle Club, Begonia,
Schulte, Valley Hills, and San Carlos.
Water Use in Acre-Feet 2020 (AF)
(preliminary values subject
to revision)
April
- June 0.63
MONITORING
OF RIPARIAN VEGETATION: Starting in June 2020, staff recorded monthly
observations of canopy vigor on target willow and cottonwood trees to provide
an indication of plant water stress and corresponding soil moisture
levels. Four locations (Rancho Cañada,
San Carlos, Valley Hills, and Schulte) are monitored monthly for canopy ratings
based on a scale from one to ten. This scale evaluates characteristics such as
yellowing leaves and percentages of defoliation (see scale on Exhibit 24-A). A total of 12 willows and 12 cottonwoods at
these locations provide a data set of established and planted sample trees that
are representative of trees in the Carmel River riparian corridor. Combined
with monthly readings from the District’s array of monitoring wells and pumping
records for large-capacity Carmel Valley wells in the California American Water
service area, the District’s monitoring provides insight into the status of
soil moisture through the riparian corridor.
Current
monitoring results for the 2020 monitoring season to date show that riparian
vegetation is below threshold moisture stress levels. The graph in Exhibit 24-A shows
average canopy ratings for willows and cottonwoods in selected restoration sites
in lower Carmel Valley. The graph in Exhibit
24-B shows impacts to water table
elevations. The types of monitoring
measurements made during June through September are as follows:
Monitoring Measurement
Canopy
ratings (See
Exhibit 24-A for trends.)
Groundwater
levels (monitoring wells) (See Exhibit
24-B for
trends.)
Groundwater pumping (production
wells)
OTHER
TASKS PERFORMED SINCE THE JULY 2020 QUARTERLY REPORT:
1.
Rancho San Carlos Bank Stabilization Project: The District continues
to irrigate the Rancho San Carlos Bank Stabilization Project just downstream of
Rancho San Carlos Road Bridge. District staff have noticed vigorous growth of
willows and cottonwood trees this summer, which will help stabilize this reach
of the river. This area experienced significant erosion in the winter of
2016-2017.
EXHIBITS
24-A Average Willow and Cottonwood Canopy Rating
24-B Depth to
Groundwater
U:\staff\Boardpacket\2020\20201019\InformationalItems\24\Item-24.docx