FOX CANYON GMA STREAM DEPLETION GRAC STREAM DEPLETION

FOX CANYON GMA STREAM DEPLETION? GRAC STREAM DEPLETION WORKSHOP AUGUST 29, 2017 BRYAN BONDY, PG, CHG CONTRACT GW MGR. – CALLEGUAS MWD BONDY GROUNDWATER CONSULTING, INC.

Kern County Los Ventura County eles Santa Clara River n Cou Ventura River Ang Santa Barbara County FOX CANYON GROUNDWATER MANAGEMENT AGENCY ty Simi Valley Ventura Oxnard Fox Canyon GMA Calleguas Creek Watershed Thousand Oaks

DO WE HAVE INTERCONNECTED SURFACE WATER? § 354. 16. Groundwater Conditions - (f) Identification of interconnected surface water systems within the basin and an estimate of the quantity and timing of depletions of those systems § 351. Definitions- (o) “Interconnected surface water” refers to surface water that is hydraulically connected at any point by a continuous saturated zone to the underlying aquifer and the overlying surface water is not completely depleted.

FOX CANYON GMA PRIMARY SURFACE WATER BODIES Coastal Wetlands

OXNARD BASIN SURFACE WATER NOT INTERCONNECTED Perched Zone – Not a “Principal Aquifer” Vadose Zone

LAS POSAS BASIN ARROYO LAS POSAS IS INTERCONNECTED Losing Gaining Shallow Aquifer Methods: Wastewater Treatment Plant Other Surface Water Discharge Synoptic streamflow surveys in 2011 and 2012 Visual monitoring of streamflow terminus since 2012 Shallow aquifer monitoring wells drilled in 2013

SURFACE WATER IS THE PRIMARY SOURCE OF RECHARGE TO LPVB EASTERN MGMT. AREA 7

ENVIRONMENTAL BENEFICIAL USE Riparian vegetation transpires ~2, 000 – 3, 000 AFY CA Gnatcatcher SW Pond Turtle Least Bell's Vireo Arroyo Chub

WE HAVE INTERCONNECTED SURFACE WATER NOW WHAT DOES IT MEAN? The surface water is principally wastewater and other discharges to the arroyo SGMA does not distinguish between natural flow and discharges GSA does not have authority to regulate quantity of discharges Wastewater plant operators have SWRCB Division of Water Rights approval to divert for recycling

WASTEWATER PLANT FLOWS AND OTHER DISCHARGES Future Worst Case? Draft

MINIMUM THRESHOLDS? § 354. 28. Minimum Thresholds – (c)(6) Depletions of Interconnected Surface Water. The minimum threshold for depletions of interconnected surface water shall be the rate or volume of surface water depletions caused by groundwater use that has adverse impacts on beneficial uses of the surface water and may lead to undesirable results. § Biggest risk of “depletion” is diversion for recycling § Very minimal extraction from shallow aquifer § Concern about future desalter projects that would pump shallow groundwater and potentially cause depletion

MEASURABLE OBJECTIVES? § 351. Definitions- (s) “Measurable objectives” refer to specific, quantifiable goals for the maintenance or improvement of specified groundwater conditions that have been included in an adopted Plan to achieve the sustainability goal for the basin. Consideration of setting MO for “aspirational goals”: § Not enforceable – does not trigger state intervention § Designed to encourage protection of riparian habitat

MONITORING? § 354. 34. Monitoring Network – (c)(6) Depletions of Interconnected Surface Water. Monitor surface water and groundwater, where interconnected surface water conditions exist, to characterize the spatial and temporal exchanges between surface water and groundwater, and to calibrate and apply the tools and methods necessary to calculate depletions of surface water caused by groundwater extractions. § How much effort should be put into monitoring given that current groundwater extractions do not appear to have a material linkage to depletion? § Expensive – who pays? ? ? § Dischargers? Shallow Desalter Project Proponents? Deep Aquifer Pumpers?

FOCUS ON SOLUTIONS How can we protect riparian habitat AND mitigate future losses of surface water inflows to basin?

ARUNDO REMOVAL 118 Moorpark 23

ARUNDO REMOVAL COST Initial Cost: $26. 5 million (good candidate for grant funding)

STORM WATER CAPTURE AND PERCOLATION USING MOORPARK WWTP PERCOLATION PONDS Divert storm flow from arroyo into unused ponds for percolation Subsurface infiltration pipes, pump, and pipes

STORM WATER CAPTURE PROJECT MOORPARK WWTP PERCOLATION PONDS COST Initial cost: $3. 7 million

QUESTIONS? Contact: bondygroundwater@gmail. com 805 -212 -0484

EXTRA SLIDES

HISTORICAL SHALLOW AQUIFER GROUNDWATER LEVELS Draft