ITEM:

INFORMATIONAL ITEM/STAFF REPORT

 

26.

QUARTERLY CARMEL RIVER RIPARIAN CORRIDOR MANAGEMENT PROGRAM REPORT

 

Meeting Date:

January 23, 2023

Budgeted:

N/A

 

From:

Dave Stoldt,

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:  This action does not constitute a project as defined by the California Environmental Quality Act Guidelines Section 15378.

 

IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings was carried out for the dry season in 2022 at six Monterey Peninsula Water Management District (District) riparian habitat restoration sites.  The following irrigation systems were in use April through November: Sleepy Hollow, deDampierre, Trail and Saddle Club, Begonia, Cypress, Schulte, and Rancho San Carlos.

 

            Water Use in Acre-Feet (AF)

            (preliminary values subject to revision)

           

            January - March 2022             0.20 AF

            April - June 2022                    0.70

            July – September 2022           1.38

            October – December 2022      0.34 AF

           

            Year-to-date                            2.62 AF

 

MONITORING OF RIPARIAN VEGETATION:   Starting in June 2022, 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 26-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.

 

Monitoring results for the 2022 season show that riparian vegetation experienced moisture stress because of the “dry” rainfall year and lack of soil moisture. It is important to note that irrigation around municipal wells is carried out to help alleviate impacts from water extraction. The graph in Exhibit 26-A shows average canopy ratings for willows and cottonwoods in selected restoration sites in lower Carmel Valley.  The graph in Exhibit 26-B shows impacts to water table elevations.

 

The types of monitoring measurements made during June - October 2022 are as follows:

 

            Monitoring Measurement                                       

 

            Canopy ratings                                                (See Exhibit 26-A for trends.)          

            Groundwater levels (monitoring wells)          (See Exhibit 26-B for trends.)          

            Groundwater pumping (production wells)

 

OTHER TASKS PERFORMED SINCE THE OCTOBER 2022 QUARTERLY REPORT:

 

1.      District staff have been participating in Technical Advisory Committee meetings with Monterey Peninsula Regional Park District, NOAA, CDFW, and McBain Associates regarding restoration of the Carmel River in Palo Corona Regional Park. Meetings have been focusing on how to restore processes along the river and encourage natural meanders and make the floodplain more accessible during lower flows.

2.      District staff have also carried out steelhead population studies at various sites along the Carmel River.

 

EXHIBITS

26-A    Average Willow and Cottonwood Canopy Rating

26-B    Depth to Groundwater

                       

 

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