ITEM:		INFORMATIONAL ITEMS/STAFF REPORTS
28.	QUARTERLY IRRIGATION PROGRAM AND RIPARIAN PROJECTS REPORT
Meeting Date:			October 20, 2008	Budgeted	N/A
From:			Darby Fuerst,	Program/	N/A
			General Manager	Line Item No.:
Prepared By:			Thomas Christensen	Cost Estimate:	N/A
General Counsel Approval: N/A
Committee Recommendation: N/A
CEQA Compliance: N/A

IRRIGATION OF RIPARIAN VEGETATION: The supplemental watering of riparian restoration plantings resumed in March of 2008 at ten Monterey Peninsula Water Management District (District) riparian habitat restoration sites. The following irrigation systems were in use March through September: De Dampierre, Trail and Saddle Club, Scarlett, Begonia, Schulte South, Schulte Bridge, Schulte, All Saints, Valley Hills, and San Carlos at Dow Property. The temporary San Carlos system was installed on August 11, 2008 and is also currently in use.

Water Use in Acre-Feet (AF)

(preliminary values subject to revision)

January - March 2008 0.01 AF

April - June 2008 2.19

July – September 2008 5.34

Year-to-date 7.54 AF

MONITORING OF RIPARIAN VEGETATION: During May through September 2008, staff recorded weekly 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 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 28-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 three of these sites (San Carlos, Valley Hills, and Schulte) using tensiometers. Soil moisture values are measured at seven 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 CAW system, the District’s monitoring provides insight into the status of soil moisture through the riparian corridor.

Current monitoring results for the 2008 monitoring season to date show that riparian vegetation is below threshold stress levels. Some signs of yellowing and defoliation are occurring in individual trees, but the overall riparian corridor still shows healthy trees. The graphs in Exhibit 28-A and 28-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 2008 are as follows:

Monitoring Measurement

Canopy Ratings (See Exhibit 28-A for trends.)

Soil moisture (tensiometers)

Groundwater levels (monitoring wells) (See Exhibit 28-B for trends.)

Groundwater pumping (production wells)

OTHER TASKS PERFORMED SINCE MARCH 2008 REPORT:

1. Vegetation Management on the Carmel River: District staff and the California Conservation Corps completed one week of successful “vegetation management” work along the Carmel River starting on September 22, 2008. Vegetation was selectively removed from four critical areas with vegetation encroachment in the channel bottom.  A total of 1,050 lineal feet of stream was opened up. These sites were chosen for their potential to direct high flows from the center of the channel toward the banks and potentially cause erosion and property damage.

2. Concrete Slab/Abutment Removal: District staff in partnership with the California Conservation Corps and National Oceanic Atmospheric Administration Restoration Center removed a concrete abutment (14 feet long, 6.5 feet wide and 2 feet thick) associated with an old bridge just below Esquiline Road Bridge. With a crew of up to 14 people and two jack hammers the concrete abutment was broken up and carried by hand out of the river bed and disposed of at the Monterey Regional Waste Management District. The slab was preventing streambed access for steelhead and may have contributed to the formation of a mid-stream island that can limit the ability of the river to pass high flows. The river will now be able to establish a natural sequence of pools and riffles with out the influence of the large concrete abutment.

EXHIBITS

28-A Average Willow and Cottonwood Canopy Rating

28-B Depth to Groundwater

U:\staff\word\boardpacket\2008\2008boardpackets\20081020\InfoItems\28\item28.doc