Groundwater and Groundwater Surface Water Interaction: How Does It Work?

Transcription

1 Napa Valley Groundwater Advisory Committee February 23, 2012 Groundwater and Groundwater Surface Water Interaction: How Does It Work? Thomas Harter University of California, Davis Groundwater Resources Association of California

2 Overview What is groundwater? How much groundwater is there? How fast does groundwater move? How do we measure groundwater? Where does groundwater come from and where does it go? How do Californians use it? Groundwater management and groundwater quality

3 What is Groundwater? An underground lake? A network of underground rivers? A rectangular network of pipelike water arteries? A giant sponge?

4 Groundwater = Water completely filling Pores/Fractures

5 Groundwater in Different Sediments and Rocks

6 How fast does water flow? water-level drop Sand

7 How fast does water flow? water-level drop Loam

8 How fast does water flow? water-level drop Sand Darcy s law: groundwater flow = hydraulic conductivity x pressure gradient

9 How do we measure hydraulic conductivity? Estimate based on sediment type (gravel, sand, silt, clay, fractured rock): => well logs (geologic logs, geophysical logs) Measure on sediment/rock cores in laboratory Estimate from specific capacity of wells: ratio of pumping rate to well water level drawdown Measure using an aquifer test: 1-day to 7-day well pumping tests Estimate from groundwater models: => matching model results to measured water levels, groundwater flows

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12 Sediments => result of erosion, water, wind, lake deposition, ocean bay deposition fractured bedrock of California s mountain ranges

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14 Unconfined Aquifer Losing stream

15 What is Groundwater?

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22 Unconfined Aquifer Gaining stream

23 Springs From: Harter and Rollins, Watersheds, Groundwater, and Drinking Water - A Practical Guide. University of California Agriculture and Natural Resources Publication 3497, 2008;

24 Fall River, NE California Basaltflow Alluvial Basin

25 Perched Water Table

26 (Semi-) Confined Aquifer

27 Artesian Well (Confined Aquifer)

28 Vernal Pools aka Seasonal Wetlands

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30 Direction of Groundwater Flow?

31 Map from: Direction of Regional GW Flow

32 The Classic Hydrology View From: Jeff Mount California Rivers and Streams Hydrograph storm flow & interflow base flow Time

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34 A Groundwater Well well screen gravel pack

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36 Hydraulic Conductivity from Borehole Logs (Estimated) Courtesy, Claudia Fawn, USGS, 2008

37 Cone of Depression near a Well from: U.S. Geological Survey, Ground Water and the Rural Homeowner

38 Local & Regional Groundwater Flow

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48 Gaining Stream

49 Losing Stream

50 Disconnected Stream

51 Dry Stream

52 Reconnecting Groundwater to Surface Water: Role of Aquifer Heterogeneity Fleckenstein et al., Ground Water 2006

53 Gaining Stream Stream-Aquifer Connection at the Regional Scale Losing or Disconnected Stream

54 Well Near a Stream

55 Well Near a Stream

56 Well Near a Stream

57 Well Near a Stream

58 Well Near a Stream

59 Well Near a Stream

60 Well Near a Stream

61 Well Near a Stream

62 Well Near a Stream

63 Well Near a Stream

64 Well Near a Stream

65 Well Near a Stream

66 Well Near a Stream

67 Well Near a Stream

68 Groundwater Dependent Ecosystems And the GW SW Interface

69 Conjunctive Use

70 Meandering Streams & Paleochannels Boulton and Hancock, Austral J Botany, 2006

71 The Hyporheic Zone

72 Losing Gaining Flow Through Woessner, Ground Water 2000

73 Where does groundwater come from and where does it eventually go? - The Hydrologic Cycle -

74 Courtesy, Claudia Fawn, USGS, 2008

75 Space and Time Disconnect between Water Supply and Water Use RAIN WATER USERS

76 California s Urban Water Users Population (Year 2000): 34 million Water Use: 8-9 MAF MAF = million acre-feet

77 California s Agricultural Water Users Irrigated Acreage (Year 2000): 9.5 million acres Water Use: MAF MAF = million acre-feet

78 California Water Infrastructure Bridging the Spatial and Temporal Disconnect between SUPPLY and USE California Water Plan, Bulletin Total reservoir storage: 40 MAF

79 Groundwater Use in California: The Invisible Storage Reservoir From: DWR California Water Plan 2009 (Bulletin )

80 Southern Tulare County Water Budget USE SUPPLY 1990 drought 1977 drought Ruud, Harter et al., 2003, 2004

81 1977 Tule River Basin: Monthly Water Budgets, Oct-Sep Ruud, Harter et al., 2003,

82 Irrigation Efficiency

83 Irrigation Efficiency

84 Groundwater Management and Groundwater Quality

85 Integrated Regional Water Management Planning toward Integrated Resource Management Planning Groundwater Surface Water Air Soil quality Energy / Carbon Landuse planning (Courtesy: Sarge Green, CSU Fresno)

86 Questions?

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