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Drought Impacts on Surface Waters and POTWs Ken Landau Assistant Executive Officer Rancho Cordova Office 1 Central Valley Water Board - 5 June 2014 Agenda Item 6
Drought Impacts on Surface Waters and POTWs
Ken Landau Assistant Executive Officer Rancho Cordova Office
1 Central Valley Water Board - 5 June 2014 Agenda Item 6
Surface Water Impacts Less Precipitation • Lower river flows • Lower lake/reservoir levels • Drier ground • Less groundwater recharge
Delta Ocean
Pumps
2 Central Valley Water Board - 5 June 2014 Agenda Item 6
Surface Water Impacts Less snow • Warmer rivers / lakes • Loss of seasonal storage
• Changed runoff pattern
Delta Ocean
Pumps
3 Central Valley Water Board - 5 June 2014 Agenda Item 6
Surface Water Impacts Warmer waters
• Hard on cold-water fish • Reduced DO saturation • Increased BOD kinetics • Reduced dissolved oxygen
Delta Ocean
Pumps
4 Central Valley Water Board - 5 June 2014 Agenda Item 6
Lower lakes / reservoirs • Bath tub ring
• Increased erosion • Increased mercury methylation
when refilled
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Lower lakes / reservoirs • Cold water pool
• Lake turnover
6
Warm Water
Cold Water
Central Valley Water Board - 5 June 2014 Agenda Item 6
Lower lakes / reservoirs • Cold water pool
• Lake turnover
7
Warm Water
Central Valley Water Board - 5 June 2014 Agenda Item 6
Lower lakes / reservoirs • Cold water pool
• Lake turnover
8
Warm Water
Cold Water
Central Valley Water Board - 5 June 2014 Agenda Item 6
Why are we worried about erosion?
• Sediment deposits – Change stream bottoms – Increase stream turbidity – Carry pollutants – metals, pesticides, nutrients
• Harder for vegetation to grow
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Surface Water Impacts
Economic Impacts • Less / poorer water supply
• Fallow land, jobs
• Less hydropower production • Reduced recreation
• Fishing, skiing, boating, hiking • Motels, grocers, rentals, jobs
Central Valley Water Board - 5 June 2014 10 Agenda Item 6
Timber Increased wild fires
• Reduced vegetation • May destroy top soil
• Erosion • Toxic runoff • Staff response to
fires
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Reduced vegetation • Reduced forage
• Over grazing
• Increased wind and rain erosion • Higher peak runoff / floods • Warmer runoff • Reduced infiltration
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POTW Impacts Conservation / Reduced Flow
• More concentrated effluent • Potential effluent violations • Possible Permit changes
• Interim effluent limits • Performance-based final limits
POTW 13 Central Valley Water Board - 5 June 2014 Agenda Item 6
POTW Impacts Water supply changes
• Shift to ground water • Poorer quality wells in use • More salt and trace metals
POTW 14 Central Valley Water Board - 5 June 2014 Agenda Item 6
POTW Impacts Lower wastewater flows • Reduced overflow risk for land
disposal • Reduced dilution for NPDES
• May change dilution for future permits
POTW 15 Central Valley Water Board - 5 June 2014 Agenda Item 6
POTW Impacts Increased demand for recycled water • State Board recycle Gen. WDRs • Enforcement discretion • Clean Water Act • Cal. Wat. Section 1211
POTW 16 Central Valley Water Board - 5 June 2014 Agenda Item 6
Irrigated Lands Reduced supply – fewer crops • Fallow land – increased erosion • Lower ILRP fees • Delayed Rice submittal alternative
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Urban Runoff Less rain – less runoff • Best water quality at monitored
ocean beaches in years
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Impacts on Water Board
• Continued work with Water Rights • Increased post-fire response • Increased recycling
– Project reviews, WDRs, construction stormwater, WQ Certs
• Permit modifications – Consider relaxing limits, IF POSSIBLE – More stringent effluent limits
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Possible permit modifications
• More concentrated effluent – more limits • Lower river flows – less dilution available
– More stringent effluent limits
• Higher background concentrations in rivers – Less assimilative capacity available – More stringent effluent limits
• Effluent cooling could become common • Major WWTP upgrades could be needed
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Questions?
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DROUGHT, GROUNDWATER, AND PERMITTED DISCHARGERS
Clay Rodgers Assistant Executive Officer
Central Valley Water Board - 5 June 2014 22 Agenda Item 6
Central Valley Water Board - 5 June 2014 23
Presentation Overview
Groundwater Cycle Potential Impacts (short & long term)
Agenda Item 6
Groundwater Cycle
Central Valley Water Board - 5 June 2014 24 Agenda Item 6
Groundwater Cycle
Central Valley Water Board - 5 June 2014 25 Agenda Item 6
Impacts
Central Valley Water Board - 5 June 2014 26
Drop in water levels
GRACE Data (from NASA)
Oct 03 – March 09
Agenda Item 6
Impacts
Central Valley Water Board - 5 June 2014 27
Overall decrease in groundwater quality
Agenda Item 6
Impacts
Subsidence
Central Valley Water Board - 5 June 2014 28 Agenda Item 6
Summary
Drought will have significant impacts Effects will be long lasting Presents significant challenges
to Dischargers and the public
Central Valley Water Board - 5 June 2014 29 Agenda Item 6
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Questions ?
Central Valley Water Board - 5 June 2014 Agenda Item 6
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Surface Water Impacts The Delta
• Reduced river flow • Increased salt water intrusion • Increased Delta and export salts
• Balance between water supply and salinity
Delta Ocean
Pumps
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POTW Impacts Conservation / Reduced Flow
• Less flushing of sewers • More concentrated sewage
• Operational changes?
POTW 33 Central Valley Water Board - 5 June 2014 Agenda Item 6
Surface Water Impacts Lower River Flows
• Less dilution • Reduce dilution in Permits • Tighter effluent limits
• Reduced aquatic habitat
Delta Ocean
Pumps
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Surface Water Impacts Increased erosion / sedimentation
• Drier ground more erosive • Reduced vegetation
• Rain drops strike soil directly • Over grazing • Fires
Delta Ocean
Pumps
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Surface Water Impacts Lower groundwater levels
• Reduced accretions to rivers • Lower river flows • Increased river temperatures • Reduced deep pool refuges
Delta Ocean
Pumps
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