ITEM:

INFORMATIONAL ITEMS/STAFF REPORTS

 

30.

QUARTERLY IRRIGATION PROGRAM AND RIPARIAN PROJECTS REPORT

 

Meeting Date:

July 19, 2010

Budgeted

N/A

 

From:

Darby Fuerst,

Program/

N/A

 

General Manager

Line Item No.:

 

Prepared By:

Thomas Christensen

Cost Estimate:

N/A

 

General Counsel Review:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A

 

IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings resumed in April of 2010 at seven Monterey Peninsula Water Management District (District) riparian habitat restoration sites.  The following irrigation systems were in use April through June: Trail and Saddle Club, Begonia, Schulte South, Schulte, All Saints, Valley Hills, and San Carlos at Dow Property.

 

            Water Use in Acre-Feet (AF)

            (preliminary values subject to revision)

           

            January - March 2010   0.00 AF

            April - June 2010           0.71

            Year-to-date                  0.71 AF

 

MONITORING OF RIPARIAN VEGETATION:   During May and June 2010, staff recorded bi-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 bi-monthly for canopy ratings based on a scale from one to eleven. This scale evaluates characteristics such as yellowing leaves and percentages of defoliation (see scale on Exhibit 30-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.  Soil moisture values are measured at all four sites using 18-inch and 36-inch tensiometers in the soil column.  Combined with monthly readings from the District’s array of monitoring wells and pumping records for large-capacity Carmel Valley wells in the Cal-Am service area, the District’s monitoring provides insight into the status of soil moisture through the riparian corridor.

 

Current monitoring results for the 2010 monitoring season to date show that riparian vegetation is below threshold stress levels.  Late spring rains and adequate river flows have helped trees in the riparian corridor remain vigorous during the early months of summer. The graph in Exhibit 30-A shows average canopy ratings for willows and cottonwoods in selected restoration sites in the lower Carmel Valley.  The graph in Exhibit 30-B shows impacts to water table elevations.

 

The types of monitoring measurements made during May through June 2010 are as follows:

 

            Monitoring Measurement                                        

 

            Canopy ratings                                     (See Exhibit 30-A for trends.) 

            Soil moisture (tensiometers)                                         

            Groundwater levels (monitoring wells)   (See Exhibit 30-B for trends.) 

            Groundwater pumping (production wells)                     

           

 

 

OTHER TASKS PERFORMED SINCE APRILS 2010 REPORT:

 


1.         Carmel River Property Owner Assistance: On May 6, 2010, District staff assisted Roy Woods and Nick Marotta (Carmel Valley property owners) by expanding their current irrigation system to accommodate riparian plants that have been planted in access areas that were associated with the bank repair project that took place last fall. Now that winter rains have ceased, District staff is coordinating with property owners who operate individual systems to help establish irrigation schedules that maintain riparian vegetation along the Carmel River.    

 

2.         Annual Carmel River Inspections: During the month of May, District staff inspected the Carmel River from Camp Steffani (River Mile 15.5) to the Carmel River Lagoon (River Mile 0.0). Annual inspections help determine the scope of work for vegetation management activities typically conducted in the fall in preparation for high winter flows, and for addressing new erosion problems and riparian ordinance violations.

 

3.         Carmel River Vegetation Management Project Notification: On June 1, 2010, District staff notified the U.S. Army Corps of Engineers, NOAA Fisheries, U.S. Fish and Wildlife Service, California Department of Fish and Game (CDFG), and the Regional Water Quality Control Board of nine sites that are scheduled for vegetation management activities this fall. A total of approximately 2,400 lineal feet of stream encompassing approximately 0.55 acre in the channel bottom will be affected by this year’s project.  The goal of the vegetation management activities is to reduce the risk of streambank erosion along riverfront properties where vegetation encroachment could potentially divert river flows into streambanks during high flow periods.

 

EXHIBITS

30-A    Average Willow and Cottonwood Canopy Rating

30-B    Depth to Groundwater

 

 

 

 

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