Case Study:
Water and Wastewater Utilities
Planning for Climate Change
CITY OF HOUSTON, TEXAS
Background
The city of Houston's Public Works and Engineering Department provides drinking water services for the greater
Houston area. Historically, the city of Houston's drinking water has been sourced from both groundwater and surface
water. However, due to local subsidence from groundwater extraction, surface water from three lakes - Lake Livingston,
Lake Houston and Lake Conroe - now provide 80 percent of the area's water supply.
The city of Houston owns a significant volume of surface water rights in the San Jacinto River and Trinity River basins.
Although the city may not be immediately threatened by water scarcity, the city wants to ensure that it is planning
appropriately and anticipating potential changes in water demand and availability.
Climate Threats
The city of Houston has evaluated the potential impacts of a multi-year drought similar to one that occurred during the
1950s, as well as a long-term version of the 2011 drought. The impacts of these extreme drought conditions might
include:
	Impacts to treatment infrastructure from lowered lake levels.
	Increased stress on groundwater sources.
	Increased demand on the city's raw water system, which could be coupled with an expected increase in demand
during hot and dry weather as seen during the 2011 drought. During this drought, unique soil conditions of the area
caused system-wide water main breaks that were nearly ten times normal levels.
Planning Process
To better understand the vulnerability of its surface water supplies, the city of Houston assessed potential climate
change impacts for Lake Livingston, Lake Conroe and Lake Houston using the U.S. Environmental Protection Agency's
Climate Resilience Evaluation and Awareness Tool (CREAT). The CREAT assessment brought together individuals
from the city's Public Works and Engineering Department to think critically about potential climate impacts, prioritize
assets and consider possible adaptation options. The city of Houston is interested in using the results of the CREAT
assessment to inform a variety of projects, including an industrial re-use project which could mitigate impacts from future
drought events.
Adaptation Measures
The city of Houston considered potential consequences of extreme drought on its drinking water infrastructure and
operations. To assess this potential threat, the city considered how potential adaptive measures would help lower
consequences. See the table below for the potential adaptive measures that were considered.
City of Houston, Texas Case Study  Page 1
SEPA

-------
Case Study: Water and Wastewater Utilities Planning for Climate Change
TYPE	POTENTIAL ADAPTIVE MEASURES
Expand demand management program
Drought Planning
Revise drought contingency plan to re-define drought stages and trigger levels, considering
impacts from a long-term drought
Future building code changes for new construction to enhance conservation
Additional and
Expanded Water
Sources
Inter-basin transfer of new water source via the Luce Bayou Project
Water resource acquisition of Aliens Creek Reservoir
Desalination of brackish surface water or groundwater
Provide reclaimed water to industrial customers in place of raw surface water
Rainwater collection and use
Retrofit intake in Lake Houston to access water at lower elevations
Contact Information
For more information regarding the city of Houston's climate adaptation planning, contact Infrastructure Planning Branch
Staff at PWEplanninq@houstontx.qov.
City of Houston, Texas Case Study  Page 2
&EPA
Office of Water (4608T)
EPA 800-Q-15-008
December 2015

-------