Page 6 - USGBC Louisiana 2017 Green Report Online

Ground Water & Stormwater

The sustainability of Louisiana’s water resources is heavily Aging water infrastructure continues to be a concern
dependent upon the management of water withdrawals across the state. Greater investment in maintenance and
and usage. A recent study by the Water Institute of the green infrastructure would support longer term
Gulf has revealed many instances across Louisiana where sustainability of the water supply.
the removal of water stored in the system exceeds the
amount of water recharging the system. Different areas of The short term abundance of surface water from heavy
the state have certain unique combinations of water usage, rainfall continues to threaten communities. Activity to
with agriculture and industry often dominating the overall remove surface water as quickly as possible has
water balance. The greatest amount of ground water is compounded the issue and current thinking is to detain and
used for rice irrigation, followed by public consumption, and retain water, allowing for percolation and replenishment of
then industry. Power generation and industry are the ground water.
largest consumers of fresh water.
Article 23 of the New Orleans Comprehensive Zoning
One commonality across the state is that a large amount of Ordinance (CZO) requires a Stormwater Management Plan
drinking water is needed to support urban and rural for building permits. The new regulation applies to any new
population centers. Projections of future population growth development or redevelopment, aside from single- or two-
reveal that, absent adaptations to change, patterns of family residences, that is five thousand (5,000) square feet
water level decline can be expected to continue. or more of impervious surface, or a total site area of one
(1) acre or more. It requires that the plan retain, detain, and
A consequence of climate change is the intrusion of filter the first one and one quarter inch (1.25”) of
saltwater into freshwater systems. Since Hurricane Katrina, stormwater runoff during each rain event.
coastal Louisiana has experienced higher than expected
salinities in traditionally freshwater marshes and
waterways.

Due to heavy pumping of certain aquifers within the Capital
area, saltwater from the south has moved across the Baton
Rouge Fault into some of the fresh water aquifers in East
Baton Rouge Parish. The threat to the area’s drinking
water has raised concern and conservation efforts have
become a high priority.