Title: Drought and Water Supply Issues in
1Drought and Water Supply Issues in
2Water Supply Concerns
Reduced supply - drought
Increasing demand
3Water Supply It all Starts Here
4The Natural Supply and Demand of Water
Evapotranspiration
Over 50 of precipitation is lost to
evapotranspiration
Precipitation
Moisture Deficit
Groundwater Recharge
Moisture Surplus
5What is Groundwater?
well
Soil
Capillary Water
Unsaturated Rock
Water Table
Saturated Rock (Aquifer)
Saturated Water
6An Example of Normal Groundwater Fluctuations
During the Year
7Wells, Springs, and Other Private Water Systems
1000 to 5000
5,000 to 10,000
10,000 to 15,000
15,000 to 20,000
gt 20,000
1990 Census data
8The Added Pressure on Water Resources
Wells drilled between 1966-1994 Average of
15,000 new wells each year!
9Private Water Supplies in PA
Total 899,483
Total 1,083,087
10Water Use
Consumptive Water Use
Septic System
Non-Consumptive Water Use
11Groundwater Mining
Consumptive Water Use
Can result from -removal of water -density of
homes
Treatment Plant
12Drought
- Meteorological based solely on precipitation
- Agricultural based on soil moisture
- Hydrologic based on stream flow, groundwater
conditions
Not correlated to air temperature
13Drought Measurements
- Precipitation
- NWS precipitation stations
- Streamflow
- USGS monitoring stations
- Groundwater Levels
- 50 wells throughout state
- Palmer Drought Index
- Computed for ten divisions
- Reservoir Storage
- Delaware River Basin
14Precipitation Data
15Stream Flow Monitoring Network
16Ground Water Monitoring Network
17Example of Groundwater Data Available on USGS
Web Site
observed
average
record low
18Palmer Drought Index
- Long term hydrologic index
- Widely used (and abused)
- Water balance method compares water input to
water demands - Complex, need 30 years of data
- Values range from 6 to 6
- Positive number surplus moisture
- Negative number moisture deficit
- Normalized to climate
19Historical Palmer Drought Index in
Pennsylvania(1930 2001)
moderate
severe
extreme
20Drought Susceptibility
- Cisterns (High)
- Streams
- Ponds
- Springs
- Shallow Wells
- Deep Wells (Low)
21Drought Stages
- Watch - warning emergency
- Each stage carries increasingly strict water use
regulations - Need three of five indices to agree on stage
- Stage recommended by Emergency Management Council
- Emergency declared by Governor
- Enforced by DEP, River Basin Commissions, police
- Separate declarations can be made by the River
Basin Commissions to control streamflow
22Managing Your Water Supply During Drought
- Obtain your well log if possible
- Rock type, depth, yield, depth to water, etc.
- Keep records
- Identify alternate sources (private and public)
- Monitor your water supply
- depth to water in the well
- flow from springs
- Monitor nearby wells and streams on the web?
- Hire a consulting hydrogeologist? ()
- Water conservation!!
23Monitoring Wells During Drought
Water Level Recorder
- Allows accurate detection of water level
- Can be easily and quickly read
- 250 - 1,000
24Planning For Your Water Needs
25Recommended Flow Rates for Homes(gallons per
minute)
Bathrooms
Bedrooms 1 2 3
2 6 10
3 8 12 14
4 10 14 16
5 15 17
26Flow Rates for Livestock Production
Flow Rate (gallons per minute)
0
8
16
24
28
32
36
39
42
45
48
50
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
12000
Peak Use (gallons per day)
Assumes relatively uniform use throughout the day
27Example
- 600 hogs _at_ 4 gpd 2,400 gpd
- Hose for hydraulic
- waste removal (1 hr) 600 gpd
- Total 3,000 gpd
- Necessary flow rate 24 gpm
28Home Water Use in Pennsylvania
29Water Conservation
- achieved by change in habit or plumbing
- voluntary 10 during watch and warning
- mandated 15 during drought emergency
- ban on non-essential use
- always controversial
- water rationing last resort
- agriculture exempt
- can be difficult to enforce
30Effect of Water Conservation
Low flow toilets
Front- loading
Low flow showerhead
aerators
Normal use 72 Conservation use 49 Total
savings 32
31Pennsylvania Water Use - 1995
32Pennsylvania Drinking Water Sources - 1995
Total Population 12,071,810
Private Ground Water
Public Surface Water
Public Ground Water
Per capita 60 gpd
33U.S. Per Capita Water Use
These numbers are calculated as the total amount
of water used by everyone (residential,
industrial, commercial, etc.) users divided by
the total population.
34Pennsylvania Water Law
- Much debate over water use during drought
- Centered on reasonable use
- DRBC and SRBC permit of large users
- Registration of 10,000 gpd users
- Permitting of 100,000 gpd
- Little protection for existing sources!
- Agricultural uses exempt
- Several bills introduced to update the State
Water Plan
35Southeast PA Ground Water Protection Area
Permit for 10,000 gpd for 30 days
Due to Groundwater Mining
36Surface Water Laws
- Riparian Rights doctrine
- landowners with property adjacent to or crossed
by a water body have the right to use the water
unchanged in quality or quantity - i.e. nobody can use the water!
- Reasonable Use doctrine
- Allows water to be used as long as other users
are not unreasonably harmed - Reasonable use defined case-by-case
- Domestic gt Navigation gt Other uses
37Ground Water Laws
- American Rule
- May withdraw water for any natural and ordinary
use without regard for neighboring users - Natural and ordinary just about anything as
long as it is on the property - Established to promote economic development
- Not meant to deal with disputes
- Deepest well and biggest pump wins!
- No guarantee of future availability
38River Basin Commissions
- SRBC and DRBC
- Issue permits for surface and groundwater
withdrawal (100,000 gallons per day) - Designate Special Protection Areas
- Declare drought emergencies
- Develop comprehensive plan for water use
- Resolve disputes??
39Drought Resources on the Web
- PA DEP drought home page
- http//www.dep.state.pa.us/dep/subject/hotopics/dr
ought/ - PA State Climatologist page
- http//pasc.met.psu.edu/PA_Climatologist/
- Mid Atlantic River Forecasting Center
- http//crab.met.psu.edu/
- Susquehanna River Basin Commission
- http//www.srbc.net/
- Delaware River Basin Commission
- http//www.nj.gov/drbc/
- National Climatic Data Center
- http//lwf.ncdc.noaa.gov/oa/climate/onlineprod/dro
ught/xmgr.htmlds - NOAA Drought Information Center
- http//www.drought.noaa.gov/
- U.S. Geological Survey
- http//wwwpah2o.er.usgs.gov/