ITEM:

INFORMATIONAL ITEMS/STAFF REPORTS

 

26.

QUARTERLY CARMEL RIVER RIPARIAN CORRIDOR MANAGEMENT PROGRAM REPORT

 

Meeting Date:

October 15, 2018

Budgeted:

N/A

 

From:

Dave Stoldt,

Program/

N/A

 

General Manager

Line Item No.:

 

 

Prepared By:

Thomas Christensen and

Cost Estimate:

N/A

 

Larry Hampson

 

 

                            

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 is currently being carried out for the summer season at six Monterey Peninsula Water Management District (District) riparian habitat restoration sites.  The following irrigation systems were in use May through September: deDampierre, Trail and Saddle Club, Begonia, Schulte, Schulte Bridge, and Valley Hills.

 

            Water Use in Acre-Feet 2018 (AF)

            (preliminary values subject to revision)

            January - March          0.82 AF

            April - June                 3.41

            July – September        4.69

            Year-to-date                8.92 AF

 

MONITORING OF RIPARIAN VEGETATION:   Starting in June 2018, 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.

 

Current monitoring results for the 2018 monitoring season to date show that riparian vegetation is below threshold moisture stress levels. 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 through September 2018 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 JULY 2018 QUARTERLY REPORT:

 

1.                  Carmel River Vegetation Management: In September, District staff carried out vegetation management at 13 sites where downed trees or standing vegetation created blockages in the active channel. The work was carried out with permits from the U.S. Army Corps of Engineers, NOAA Fisheries (NMFS), U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, and the Regional Water Quality Control Board. The work will reduce the risk of streambank erosion along riverfront properties.

2.                  Rancho San Carlos Bank Stabilization Project:  The District contracted with Empire Landscaping in order to carry out a bank stabilization project just downstream of Rancho San Carlos Bridge. This area experienced significant erosion in the winter of 2016-2017. The Rancho San Carlos Bank Stabilization Project is currently underway with a projected completion date of October 31, 2018.

3.                  Sleepy Hollow Steelhead Rearing Facility Intake Upgrade: The Mercer-Fraser Company (from Eureka, Ca.) began construction at the facility in early September.  Instream work is expected to be completed prior to October 31.  All project work is scheduled to be completed by May 2019.

4.                  Instream Flow Incremental Method Study: Staff is working with Cal-Am on a response to NMFS comments about use of the IFIM model to evaluate Los Padres Dam alternatives.  NMFS position is that the model cannot accurately predict changes in habitat in a dynamic streambed.

5.                  Los Padres Dam Long-Term Plan:  Balance Hydrologics completed a sediment transport simulation for controlled releases of sediment from Los Padres Reservoir.  Draft results indicate up to five feet of aggradation in the bottom of the channel along the lower nine miles of the river over a 60-year model period.  The Technical Review Committee comprised of MPWMD, Cal-Am, and agency staff is continuing to review results. 

 

HDR, Inc. presented a draft set of fish passage alternatives that includes construction of a permanent fishway adjacent to the existing spillway, improvements to the existing trap and truck facility and installation of a reservoir collector at various locations within the existing reservoir to improve downstream passage.  NMFS suggested that no alternatives can be finalized without considering data from the ongoing steelhead tagging program.  Initial results are not expected until late 2019.

 

EXHIBITS

26-A    Average Willow and Cottonwood Canopy Rating

26-B    Depth to Groundwater

                       

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