Sawmill Wetlands

More info and photos:

The Sawmill Wetlands page on Ohio Department of Natural Resources site

FLOW's fall 2020 newsletter featuring recent preservation work

OSU capstone project 2021 - Sawmill Wetlands Forest Assessment

OSU capstone project 2021 - The bats of Sawmill Wetlands

How Sawmill Wetlands was saved from development
Thanks to the effort of many dedicated advocates, Sawmill Wetlands was saved from being developed in spite of a deed restriction limiting the wetlands to being used and occupied solely for public purposes. Read the full story here.

Vernal Pools & Trees
It is the vernal (spring) pool habitat which gives Sawmill Wetlands their name. A unique balance of clay soils, rainfall and the surrounding trees have made this natural system sustainable (able to survive year after year).

Vernal pools start to collect water in winter, supporting life which feeds on leaves and other 'debris' on the forest floor. Then as new leaves form, water is drawn up through the tree roots, drying up the pools. In fall, leaves fall from the trees, providing more food for future generations...and so the cycle continues!

Wetland Habitat
The woodland vernal pools at Sawmill Wetlands are temporary bodies of water that are typically wet by late winter and then dry up in early summer. The seasonal nature of this habitat supports many species, such as salamanders and fairy shrimp, which are uniquely adapted to thrive only in areas without permanent water (avoiding predators including fish).

Sadly, Ohio has lost over 90% of its original wetlands, a large number of which were vernal pools, one of the many reasons that protection of this rare urban habitat is so important.

Wetland Shrubs and Plants
Several beautiful native shrubs and plants such as Buttonbush, Jack-in-the-Pulpit and Gray's Sedge thrive only in these shaded wetland areas where the soils are rich and permanently moist.

Since they are native to Ohio these unique plants provide important habitat and food for the animals which live here.

Cycles of Life
Observe an oak tree that has fallen to the ground in a wind storm. Nature never lets anything go to waste though (the perfect recycler!); the fallen tree will slowly be broken down by life on the forest floor, including fungi and insects. This natural process returns precious nutrients to the soil, allowing acorns to grow up into new oak trees.

The "Big Woods"
“When I was ten years old my family moved to an old farm house located near here. This was back in the 1940's where our old house stood is now a parking lot, but one nice thing is that this portion of what my brother and I referred to as the 'Big Woods' is still here. I have fond memories of chasing through the magnificent Beech trees scattered throughout.

The survival of these woods now is about the need for a little bit of green space among the surrounding parking lots, roads, businesses and houses.”

Bob Thompson, local resident (from a letter to ODNR – Feb. 3, 2013)

Boardwalk through
the vernal pools

Vernal pools

Dirt trail through the forest

Fairy shrimp – Anostraca, one of the four orders of crustaceans in the class Branchiopoda, can be found in the vernal pools

Some of the diverse vegetation found in the wetlands




Virginia Waterleaf


Turkey Tail

Grey Dogwood

Below: Sawmill wildlife captured by Carol Shurlow (identifications through iNaturalist)

Golden Sweat Bee - Augochlorella aurata

Nobile scoliid wasp - Scolia nobilitata Fabricius

Widow Skimmer - Libellula luctuosa

Long-legged Fly - Condylostylus patibulatus

Margined Leatherwing Beetle -
Chauliognathus marginatus

Beetle - Hoshihananomia octopunctata

watchful chipmunk

White tailed deer

Purple coneflower

Male goldfinch

Tree swallows

Orchard orb weaver

Water Quality Monitoring at Sawmill Wetlands 6-8-22

summary by Eileen Sawyer

Water level 4.5" next to the dock

Notable insects and macroinvertebrates that were missing or scarce:

  • Very few mosquito larvae

  • No water beetles, dragonfly or damselfly larvae

  • Very few ostracods

  • No green flatworms

We found:

Ostracods (seed shrimp), if details are noted, it was under the microscope

  • 204 ostracods in general

  • 67 ostracods of the hairy green & white pattern

  • 2 green-colored ostracods

Water fleas (Daphnia). If a genus is listed, it was usually seen under the microscope.

A reddish color can sometimes indicate stress per my books. The water is low enough now that “pockets” are forming so it’s possible for Daphnia to be stressed in one area as their water lowers and not in another where there is still a good water column. That is not definitive, but it’s interesting to watch this.

  • 324 reddish water fleas

  • 85 D. pulex (short tail)

  • 75 water fleas, no color noted

  • 5 D. pulex reddish in color

  • 3 Simocephalus water fleas (flat butt), 2 of them with an ephippium inside

  • 2 tan water fleas had 2 ephippiums in their brood sacks with two eggs in each

  • 4 water fleas seen under the microscope in a “top view” had a very odd scalloped butt shape with two “bristles” that I didn’t recognize at all.

  • 2 D. laevis (long tail and pinkish)

  • 1 ephippium (resting egg) loose in the water with one egg inside

  • 1 pop-eyed water flea possibly Cereodaphnia genus though I’m not sure.

Cyclops copepods (We hadn’t seen many at all to this point and it’s interesting to see them now when with many other pools it’s much earlier in the season.)

  • 80 cyclops copepod with no eggs and tan in color

  • 6 cyclops copepods with eggs and tan colored

  • 1 mottled gray cyclops with no eggs

  • 1 almost transparent cyclops with twin egg sacks

Other aquatic life

  • 9 flatworms of a gray or dark color

  • 3 ram’s horn snails, alive

  • 3 red water mites

  • 3 “round-headed” water tigers, likely of the Agabus genus

  • 2 aquatic worms with zigzag guts and a flattened tail with “finger” features

  • 2 mosquito larvae

  • 1 Aquatic worm, thread like

  • 1 backswimmer (legs are up versus water boatmen whose legs are downwards)

  • 1 live fingernail clam

  • 1 large live spiral snail

  • 1 water strider


6-8-22 Sawmill pictures.pdf