ASBPA's 2015 National Coastal Conference:
"Broadening Coastal Perspectives"
Oct. 14-16, 2015
Successful swamp restoration in the Pontchartrain Basin
Eva R. Hillmann, Andy Baker, David Baker, Kristen Butcher, Theryn Henkel, and John Lopez
The Lake Pontchartrain Basin Foundation, UNO-CERM Suite 339, 2045 Lakeshore Dr, New Orleans, La. 70122
Abstract for ppt presentation
The estuarine swamps and marshes of the Pontchartrain Basin are ecologically significant and productive habitat.
They provide breeding grounds and food resources for birds and fish, are effective habitat for nutrient cycling as
well as long term carbon storage. These wetlands also provide storm surge protection for the people living within
southeast Louisiana’s coastal areas. Land loss within the wetlands of the lower Pontchartrain Basin has been a
problem for decades and can partly be attributed to the leveeing of the Mississippi River and the consequent
disconnect between the river and the wetlands of the lower basin. Historically, these wetlands were receiving
wetlands of seasonal river flooding. The Caernarvon Freshwater Diversion reconnects the Mississippi River to the
wetlands of the lower Pontchartrain Basin. The intent of the diversion was to reduce surface water salinity by
reintroducing pulses of fresh river water. The diversion was not intended or designed to move river sediment and
build land. However, the diversion has built over 600 acres of land in the past 25 years, most land building occurring
in the last 10 years and in spite of operational inefficiency in terms of effectively using the Mississippi River
sediment load. The state of Louisiana Master Plan incorporates proposed sediment diversions as a means of
combating land loss in southeast Louisiana. Yet, limited information exists about how fresh river water will affect
the potential for reforestation in the now mostly intermediate and brackish marshes of the lower Pontchartrain Basin.
The Lake Pontchartrain Basin Foundation (LPBF) has partnered with the Restore the Earth Foundation (REF) and
the Coalition to Restore Coastal Louisiana (CRCL) to plant more than 2,000 trees in the receiving basin of the
Caernarvon Diversion using locally grown trees and community volunteers. Since 2010, we planted five different
species of trees (Taxodium distichum, Nyssa aquatic, Acer rubrum, Nyssa sylvatica and Fraxinus pennsylvanica) at
different locations in the receiving basin of the diversion. All tree species were not planted in equal numbers, at each
planting event or at all locations. Proportionally, more T. distichum was planted than all other tree species. Four
hundred trees were tagged for monitoring. After 4 years of monitoring, 70% of planted trees survived when tree
guards are properly and quickly installed at the time of planting. On average, trees grow 0.5-0.7 meters in height per
growing season and increase in diameter at breast height (dbh) by 1.2-1.4 cm. In 2015, LPBF and its’ partners
expanded the reforestation effort and planted an additional 20,000 trees in the basin. Ten thousand trees were
planted in the Caernarvon area and 10,000 trees were planted along the north shore of Lake Pontchartrain. Twelve
hundred trees were added to the reforestation tree monitoring program. This effort will help clarify the potential for
wetland restoration and coastal protection through wetland reforestation in coastal Louisiana.
Eva R. Hillmann
POB1944, Ponchatoula, LA 70454
984-634-4243
erhillmann@gmail.com
Eva Hillmann is a coastal scientist with LPBF and has been with the foundation for 3 years. She is also a phd student
at Louisiana State University studying submerged aquatic vegetation and carbon storage along the northern Gulf of
Mexico.