ITEM:

INFORMATIONAL ITEM/STAFF REPORT

 

24.

QUARTERLY CARMEL RIVER RIPARIAN CORRIDOR MANAGEMENT PROGRAM REPORT

 

Meeting Date:

January 27, 2022

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 2021 at eight 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, Schulte Downstream, and Rancho San Carlos.

 

            Water Use in Acre-Feet (AF)

            (preliminary values subject to revision)

           

            January - March 2021             0.15 AF

            April - June 2021                    0.69

            July – September 2021           1.81

            October – December 2021      0.34 AF

           

            Year-to-date                            2.99 AF

 

MONITORING OF RIPARIAN VEGETATION:   Starting in June 2021, 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.

 

 

Monitoring results for the 2021 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 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 - October 2021 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 OCTOBER 2021 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

24-A    Average Willow and Cottonwood Canopy Rating

24-B    Depth to Groundwater

                       

 

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