Hydrology and Wetland Restoration for Human Subsistence and Regional Biodiversity - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 130

TABLE 9.2
Hydrologic Comparison of Outlet Types

One Stage
(Ditch Plug)

Two Stage/
Operable Natural

Average number of summer bounce events > 0.5 ft 3.7 10.1 9.6

Average summer bounce height (ft) 0.98 0.87 0.99

Average bounce duration (days) 72.7 43.6 37.7

Average spring bounce (ft) 1.00 1.36 1.52

Average yearly fluctuation (ft) 1.63 2.18 2.11

Measured Water Levels
Total range of measured water levels (ft)

2.30 2.50 2.99

Seasonal drawdown (ft/day) 0.015 0.020 0.021

s Ummary
This study provided a strategic understanding and a framework for large-scale wet-
land restorations. We also became aware of a keen need for an adaptive approach, and
sideboards to define response-nonresponse approaches, to restoration as follows:

1. The study of nature can show the most successful way to restore ecological
systems.

2. Strategically locating start-ups is very important, especially in larger
projects.

3. The design process for projects is very important. For larger projects in par-
ticular, defining adaptive management triggers, designs to allow stochas-
tic events to play out (e.g., fire, insect infestation, hydrological cycles, and
blowdown in forests), is very important.

4. In the design of wetland restoration projects, matching the desired out-
comes of a project to the watershed and site characteristics determines if
restorations fall within three broad wetland quality categories for deeper
and shallow depressional systems.

5. Site selection for wetland restoration and the strategy for buffering hydrol-
ogy, hydraulics, and water quality from agricultural and developed water-
sheds will closely influence the levels of wetland biodiversity and quality
achievable in a wetland restoration.

6. If higher biodiversity wetland restorations are desired in locations with
higher watershed ratios, additional measures will be required. A reduc-
tion in watershed ratio will provide associated reductions in bounce, and
increased water quality and biodiversity. This can be done by increasing the
size of the proposed wetland, increasing upstream storage, perhaps restor-
ing other dispersed wetlands or otherwise impounding water, and diverting
water around the subject wetland restoration site. Buffering, planting more
perennial vegetation in the watershed, and active vegetation management