ITEM:

INFORMATIONAL ITEMS/STAFF REPORTS

 

24.

QUARTERLY IRRIGATION PROGRAM AND RIPARIAN PROJECTS REPORT

 

Meeting Date:

October 18, 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 from April through September: 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                     1.33

            July – September 2010 3.04

            Year-to-date                            4.37 AF

 

MONITORING OF RIPARIAN VEGETATION:   During the period May through September 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 every other week 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 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.  Soil moisture measurements are conducted at all four sites using tensiometers.  Soil moisture values are measured at four stations with 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 California American Water system, 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.  Some signs of yellowing are occurring but the overall riparian corridor still shows obviously vigorous trees. The graphs in Exhibit 24-A and 24-B show average canopy ratings for willows and cottonwoods in selected restoration sites in the lower Carmel Valley and impacts to water table elevations.

 

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

 

            Monitoring Measurement

            Canopy Ratings                                                (See Exhibit 24-A for trends.) 

            Soil moisture (tensiometers)                                         

            Groundwater levels (monitoring wells)   (See Exhibit 24-B for trends.) 

            Groundwater pumping (production wells)                     

           

 

 

OTHER TASKS PERFORMED SINCE J  ULY’S 2010 REPORT:

 


1.         Public Outreach and Education: On August 26, 2010, the District’s Riparian Projects Coordinator, Thomas Christensen and Field Biology Assistant, Elizabeth Geisler gave presentations to freshman biology classes from Carmel High School. Topics included information on the Monterey Peninsula Water Resource System, MPWMD’s Environmental Protection Program, the Carmel River steelhead life cycle, and specific issues related to the Carmel River watershed.    

 

 

 

EXHIBITS

24-A    Average Willow and Cottonwood Canopy Rating

24-B    Depth to Groundwater

 

 

 

 

 

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