Flooding or Precipitation: What is the Dominant Source of Moisture Sustaining a Backwater Bottomland Hardwood Forest?

Author(s): Johnson, D.

When modeling the potential impact of the Yazoo Backwater Pump Project on the Bottomland Hardwood Wetlands, the Corps assumed the precipitation played an insignificant role in the sustenance of these wetlands. That assumption will be examined through the use of a water budget equation and groundwater monitoring wells.

The dominant water demand in forested areas is from evapotranspiration. It is generally presented that a forested area will be a wetland if precipitation exceeds evapotranspiration. A wetland water budget is actually much more complicated than that. Forested wetlands have four potential sources of moisture: precipitation, surface water, groundwater, and tidal, and four potential methods to lose water: evapotranspiration, surface runoff, infiltration into groundwater and tidal. Yazoo Basin wetlands are not affected by tides and are disconnected from the alluvial aquifer by a confining clay layer. Thus there are only two remaining sources of moisture: precipitation and surface water (riverine flooding). This presentation will compare the relative roles of these two sources of moisture to the forested wetlands in the Yazoo Backwater Area.


Technical Presentations

  • Delta Water Quality
  • Delta Water and Agriculture
  • Wetlands
  • Water Quality
  • Sediments
  • Non-Point
  • Management and Sustainability
  • Wood Treatment
  • Modeling
  • Soil and Water Treatment


Responsible Site Design: Implementing Innovative Stormwater Management Strategies

The primary goal of the workshop is to create a dynamic learning experience that examines the role of stormwater management in the built environment. The workshop will focus on integrating ecologically sound water management approaches into site design. After the workshop, attendees will be familiar with the following concepts and technical issues:

  • Knowledge of the stormwater treatment chain
  • Knowledge of the impact of land use codes on stormwater management
  • Application of a design process that mitigates the effects of stormwater on-site
  • Knowledge of the relationship between land use codes and design for innovative stormwater management


For information contact:
Jessie Schmidt
Box 9680
Mississippi State, MS 39762