Wetland Management
Sandhill’s wetlands are carefully managed through water level regulation and controlled burns.
Natural precipitation is the only source of water that collects in Sandhill’s many marshes and flowages. Wildlife technicians control the water level in these flowages in a couple of ways. They create earthen dikes and elevated roads that keep the water higher on the upstream side. They install spillways on these dikes to rid flowages of excess water. Wildlife techs also install and regularly manipulate water control structures specially constructed of culverts that pass beneath the earthen dikes and roads. The management staff may either remove or add "stop logs" that are stacked on top of each other in a vertical or "riser" culvert to lower or raise water levels. This system relies on gravity to move the water. If a wildlife technician removes logs from the riser, the water level drops. If a technician adds logs, then the water level rises. In spring and summer the management team draws down the water level to encourage a lush growth of green seed-bearing plants that are important to migratory birds that stop at the flowages in fall.
Where possible, the Sandhill Wildlife Management team drains wetlands on a 3-4 year cycle to mimic natural drought conditions. The mudflats that lay exposed after a wetland has been drawn down readily decompose dead plant materials and attract a variety of wading birds and shorebirds from the tiny solitary sandpiper and killdeer to the lumbering great blue heron that seeks out tadpoles in lingering pools. The nutrients released through plant decomposition are readily used by sprouting plants after the basin is slowly reflooded. Water clarity and plant nutritional value typically increases following a draw down.
In late summer, marshes that have been drawn down are burned, if weather permits. Fire helps reduce rank weed growth and the spread of shrubs that would eventually choke out plant life beneficial to wetland wildlife. Prescribed burns also clean out stagnant areas clogged with dead, decaying plant matter while releasing valuable nutrients trapped in the duff. These nutrients are then available for use by living plants and animals. Following the "draw downs" and prescribed burns, the Wildlife Management team refloods the basins in late summer after the plant seeds have ripened. These reflooded marshes and flowages provide a welcomed resting spot and a well-stocked smorgasbord of food for a wide variety of migratory birds who will be winging their way south across Wisconsin in the autumn months. Thousands of migratory birds stop over at Sandhill to take their fill of our bountiful supply of food. Once an old flowage is "rejuvenated" in this manner, the benefits of our marsh management practices will last several years.
Learn more about Sandhill Wildlife Management Programs:
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