The Ice Pond
I have a client that was required to remove an in-line pond that was built in the headwaters of a Use Class IV, recreational trout stream. The “ice pond” was built around 1905 and is a spring seep. The pond never had fish, but was always considered a good “herp” pond for amphibian breeding. Although historic, because the pond was built to cut winter ice for an estate home on a farm with a once beautiful allee driveway, lined with old eastern red cedar, the pond discharged warm water to the headwater stream.
The goal was to eliminate the thermal loading and restore the headwaters, while still providing a herp pool. Our design was to breech the dam and build a Piedmont step pool to convey base flow to the natural forested stream. We therefore converted the majority of the open water pond into a forested and emergent wetland with a smaller area of open water. The summer of 2015 constitutes year-4-of-5 for mandatory monitoring, where we submit trend analysis reports to the U.S. Army Corps of Engineers and the Maryland Department of the Environment. The following are some photos of the project site from today’s field work.
The outlet (drain-plug) for this pool is a rock level-lip spreader, which is a series of four rock step pools that ties in the pond to the receiving stream. The pond has a very discrete series of zones, where aquatic plants occur in bands based on hydrology and hydrophytic preference/tolerance. The open water yields to zone of floating aquatic vegetation known as pondweed (Potamogeton bicupulatus), which then as the inundation drops to about 4-inches deep, yields to water plantain.
The next band of shallower inundation is a zone of pickerelweed and then a band of soft-stem bulrush. The next zone is saturated soil consisting of a band of rice cutgrass, mixed with occasional fringed, lurid, hop, fox and bladder sedge, along with patches of beaked spike rush. The back zone (capillary fringe) of saturated soil is comprised of woolgrass, transitioning to aerated soils with showy forbs that include swamp milkweed, blue vervain, New York ironweed, square-stem monkey flower, cardinal flower and seedbox.
The majority of the created wetland basin is well off to the right of this photo. The area to the left of the photo shows the remains of the dam and top of dam, where the original pond elevation occurred. Our step pool used the weep of the former pond, which was effectively an earthen spillway, as the pond was so old, it did not have a piping system.
The following are a few photos of various herbaceous plants and grass-sedge-rush that were in flower and/or inflorescence:
Carolina Nightshade (Solanum carolinense).
Skeletonweed (Chondrilla juncea).
Lurid Sedge (Carex lurida).
Woolgrass (Scirpus cyperinus).
Green Bulrush (Scirpus atrovirens).
Umbrella Sedge (Cyperus strigosus).
The spray of Water Plantain (Alisma plantago-aquatica) flowers.
Pickerelweed (Pontederia cordata).
Eastern Pondhawk (Erythemis simplicicollis).
Arrowhead (Sagittaria latifolia).
Square-Stem Monkeyflower (Mimulus ringens).
Swamp Milkweed (Asclepias incarnata).
Rice Cutgrass (Leersia oryzoides). The blue in the background is pickerelweed.
Blue Vervain (Verbena hastata).
Curled Dock (Rumex crispus).
An aggregate of Curled Dock.
Lady’s Thumb Smartweed (Persicaria maculosa).
A cabbage butterfly on a flowering Canada Thistle (Cirsium arvense).
Yarrow (Achillea millefolium).
Wineberry (Rubus phoenicolasius), of which I ate dozens.
White-Top Fleabane (Erigeron annus).
We also observed jewelweed and dye bedstraw in flower today. Great day in the field.