Hydrology and Wetland Restoration for Human Subsistence and Regional Biodiversity - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 121

areas. Interestingly, many human parasites “piggyback” on outbreaks and spread
to humans on programs that alter rivers and their hydrology such as occurred with
the Egyptian Aswan High Dam experience. The Iraqi Mesopotamian marsh areas
may be especially vulnerable at this moment in time owing to the excessive water
pollution from the upgradient urban centers discharging increased volumes of
untreated human sewage (pathogens) to the rivers as a result of infrastructure loss
during the recent wars. Reconstruction of the extremely damaged Baghdad sewer-
age system should be a public health priority and may need to precede reflooding the
Mesopotamian marsh systems (see chapters 18, 19, and 20).
PRINCIPLES FOR SCALING UP
Principles are important for wetland restorations at any scale. These become very
important as project scale, regional aridity, and the percentage of urban, industrial,
or agricultural land use and development change in the tributary watershed influ-
ence a restoration program. The following are understandings and principles used
by Applied Ecological Services, Inc., in the restoration of other large wetland com-
plexes that may be useful to consider for the Mesopotamian marshes.
1. Understanding the watershed context for wetland restorations is a criti-
cal factor in restoration success; existing (or possible) government policies
related to the river may be critical.
2. Biological productivity and availability of larger (human) consumable
foodstuffs often increase with some disturbance and nutrient loads in
tributary watershed.
3. Biological diversity of native plant and animal species appears to be great-
est in watersheds with the lowest agricultural conversion, lowest defores-
tation percentage, and lowest percentage of imperviousness or developed
land.
4. Biological diversity of all species (including invasive species) may elevate
with intermediate disturbance levels.
5. Biological diversity of all species declines with high hydraulic volatility
and increased nutrient loading regardless of whether these changes are
owing to impervious watershed conversion, row crop agriculture, industrial
discharges, or domestic sewage.
6. On the annual hydrograph, a predictable seasonal high-water level and the
trajectory to a seasonal low will be less predictable with an increased per-
centage of agricultural, urban, and industrial development.
7. For developed landscapes with the most land converted to annual crops and
human development, land stewardship appears to be essential to maintain
high levels of productivity and moderate diversity.
8. Significant incremental cost savings will accrue from seed bank and refugia
analyses used to design an integrated stewardship program consistent with
stakeholder participation and culture early in a project.
9. Cultural engagement is essential to any large-scale wetland restoration pro-
gram. Success will be driven by the residents.