Municipal water needs in Travis Municipal water needs in Travis County, selected water-policy County, selected water-policy

shortcomings, and water shortcomings, and water conversation measuresconversation measures

Raymond Slade, Jr., PH

Certified Professional Hydrologist

Slide show organizationSlide show organization• Drought Drought • Texas Water PlanTexas Water Plan• Municipal water supply needs in Travis CountyMunicipal water supply needs in Travis County• Selected water policy shortcomings in TexasSelected water policy shortcomings in Texas• Effective water conservation measuresEffective water conservation measures

Google “Texas flood”…Google “Texas flood”…

DefinitionsDefinitionsWhat Texans know about waterWhat Texans know about water

You might get Stevie Ray Vaughn playing the song “Texas flood”

Definitions…Definitions…

Google “drought”…Google “drought”…

You might get a TV meteorologist defining drought as an annual rainfall deficit

Father Guido Sarducci Vatican Weatherman, SNL

It’s gonna rain or…

Typical drought cycleTypical drought cycle

From TWDB

Start here

agriculture agriculture

StreamflowReservoirs & Groundwater

StreamflowReservoirs &Groundwater

Decreasing numbers represent greater drought intensity

Green—wetter than normalGold – drier than normalEdwards Plateau

Through March 18, 2015

Assessment of current droughtAssessment of current drought

 

Hydrologic drought index

1952-57 drought more intense than current drought

Indicates substantial flooding after severe drought

Reality—how we deal with droughtReality—how we deal with drought

Start here

i.e., proposition 6

Source and fate (water budget)

Data values in million gallons per day

90%

8%

2%

99%1% <1%

% of inflow % of outflow

consumption

border flow

Why Texas droughts occur fast and are intenseWhy Texas droughts occur fast and are intense

2 reasons

99% of source water to Texas from rainfall but about 90% of that lost to evapotranspiration thus only 10 % of rain available for use

Texas Water PlanTexas Water Plan1961 19901968 1984

19971992 2002 2007

Previous plans

Texas Water Plan 2012Texas Water Plan 2012 Purpose of Plan

Estimate current and future water needs (shortages) and identify water management strategies and associated costs to meet future needs.

http://www.twdb.state.tx.us/wrpi/swp/swp.asp

Based on

Data and analyses of current and future population, water use, and water availability (every 10 years from 2010 to 2060)

Severe drought conditions (water demand at maximum and supply at minimum)

6 water use types: i.e., municipal (urban & rural), irrigation, livestock, manufacturing, mining, and steam electric)

Texas Water Development Board

Existing water supplies - the amount of water that can be produced with current permits, current contracts, and existing infrastructure during severe drought (1950s drought).

Water Demand Projections - Quantity of water projected to meet the overall necessities of an area in a specific future year.

Water supply needs (shortage) - projected water demands in excess of existing supplies that would be legally and physically available during a severe record (1950s drought).

Water management strategies - projects and associated amount of water designed to meet needs for additional water supplies during drought. Proposition 6 money to fund strategies.

Definitions of water category terms in the Definitions of water category terms in the Texas Water PlanTexas Water Plan

Calculation of water needs (shortages)

Calculations made for 1950s type severe drought

Water Supplies from the Water PlanWater Supplies from the Water Planbased on 1950s drought conditionsbased on 1950s drought conditions

200-year drought 50-year droughts

20-year drought1950s drought compared to Texas droughts from past 2000 years based

on tree ring analyses

In Travis CountyIn Travis County

Current and future municipal water needsCurrent and future municipal water needs

Municipal (urban and rural) water needs (shortages) Municipal (urban and rural) water needs (shortages) for Travis County for Travis County (based on 1950s drought)(based on 1950s drought)

2010 “Severe” drought conditions 2030 “Severe” drought conditions

28,000 peopleNeed volume = 16% of Lake Austin

105,000 peopleNeed volume = 60% of Lake Austin

Service areas--Travis County municipal water shortages, 2030(based on 1950’s drought)

2060 “Severe” drought conditions2060 “Severe” drought conditions (based on 1950s drought)(based on 1950s drought)

1.78 million people; Need volume = 3.7 times greater than Lake Austin

Need(shortage)

Austin’s water source: the Highland Lakes

Why is inflow being reduced to Lake Buchanan19 upstream major reservoirs—some less than 5 to10% full

39% decrease in inflow

Selected water policy shortcomings in TexasSelected water policy shortcomings in Texas(pertinent to Austin water sources )(pertinent to Austin water sources )

Lack of proper regulation of groundwater pumpage

• June 1904: Texas Supreme Court laid the foundation of Texas groundwater law: the rule of free capture. “Because the existence, origin, movement, and course of such waters, … are so secret, occult, and concealed that an attempt to administer any set of legal rules …would be impossible.

• Rule of free capture: Landowner can pump as much groundwater as wanted from beneath their land, regardless of the effects on neighboring wells, so long as they are not “wasting” the water. (Based on oil and gas reserves—groundwater moves). Exception—jurisdiction of Groundwater Conservation Districts. Most of Travis County not in a district.

• In Edwards Aquifer Authority vs. Day (2012), Texas Supreme Court rules that Groundwater districts may impose “reasonable” limits on pumping from wells within their boundaries, but a landowner may sue the district for compensation if limits are excessive.

• In Edwards Aquifer Authority vs. Bragg Pecan Farm (2013), the Texas Fourth Court of Appeals ruled that the Edwards Aquifer Authority owes landowners money for “taking” their groundwater by limiting pumping.

This could occur in most of Travis County

Areas in white not protected by a Groundwater Conservation District

Water developer can obtain right from landowner to pump unlimited water from areas not protected by a GCD

Proposition 6Proposition 6

• What does Proposition 6 do?• Transfers $2 billion from the State’s Economic Stabilization

Fund to the State Water Implementation Fund

• How will the money be used?

• Support projects identified in the State Water Plan. The TWDB “shall undertake to apply” 10% of the funds for rural political subdivisions and agricultural water conservation and 20% for water conservation and reuse. The money may be used for low-interest loans, and other methods of financial assistance for public entities developing and managing water supplies.

Lack of regulatory water conservation measures

Five water conservation measuresFive water conservation measures1. Fix leaking pipes and canals: Water conveyance losses in

Texas are estimated to be about 600,000 acre feet per year, a value equal to the existing Statewide municipal water need (shortage).

2. Use urban Xeriscape, less water-thirsty vegetation: About one-half of residential water use is for lawns.

3. Remove thirsty rural phreatophytes: For example, the water loss due to transpiration from tamarix (salt cedar) and mesquite in the main stream flood plain in the Colorado River in west Texas is equivalent to the long-term mean flow in the river--136 million gallons per day.

90% of Tx water lost to ET

4. Residential greywater systems: Use of greywater (water from sinks, tubs, and washing machines) to irrigate lawns would cut residential water use in half.

Rainwater harvesting5. Rainwater harvesting5. Rainwater harvesting

Texas water sourceFlow from other states

PrecipitationFate of source water

Evaporation and transpiration

Runoff to streams, lakes, and groundwater

1% 99%90% 10%

Residential water supply from surface water or groundwater

Summary: Each house using water from surface water or groundwater uses the same amount of source water as 10 houses using rainwater harvesting

Residential water supply from rainwater harvesting

90 gallons of source water lost for each 10 gallons of water used

Almost all source water used—no lost water

Good news--new source of waterGood news--new source of water

From TWDB

The solution to Texas water problemsThe solution to Texas water problemsBuild water towers everywhere