Pealiquor Road Stormwater Management Retrofit

In the concept phase Sustainable Science gathered soils, topographic and drainage data, met with the County and the affected landowners, including an onsite meeting in August 2022, and laid out a stormwater wetland fed by ditch enhancements, with culvert improvements at the road. FieldDoc pollutant load modeling supplied the metrics table for the County's grant application, and UMD Sea Grant Extension prepared the application materials and the drainage area map.

With the design contract in place, the firm gauged the watershed from April 2 through December 16, 2023, using five pressure transducer gauges (three in surface water at the ditch, the perennial stream and the pond outlet, and two groundwater piezometers in the proposed wetland area) and a tipping rain gauge, and surveyed monthly stream transects. Three significant runoff events were recorded, the largest from April 28 to May 5, 2023, which produced 62.94 acre-feet of runoff and a peak of 54.0 cfs. The upper watershed responded dramatically to storms, while the lower watershed and the stream showed no appreciable response and stable cross-sections, which pointed the design at the upstream ditches and the road crossing rather than the stream. The piezometers showed uniformly permeable sands beneath the proposed wetland, a condition the design relies on.

The Caroline Soil Conservation District approved the erosion and sediment control plan, and Sustainable Science prepared a Critical Area Simplified Buffer Management Plan for Caroline County Planning and Codes covering removal of two 18-inch trees to reach the breached pond pipe, with 2,000 square feet of native woody plantings as mitigation. During construction the firm coordinated with MDE's Tidal Wetlands Division, which confirmed on April 24, 2026 that in-kind replacement of the outlet pipe and tide gate needed no tidal authorization and that a turbidity curtain could be used without one. MDE and the Soil Conservation District approved a construction sequence revision on June 1, 2026.

Construction was funded through an MDE grant. The Center for Watershed Protection provided construction oversight and punch lists for the County, and UMD Sea Grant Extension advised on the planting plan.

The retrofit produced a 1.6-acre stormwater wetland, larger than the 1.5 acres in the concept, with its bioswales, check dams, the new road crossing and the restored pond outlet. Sustainable Science's revised FieldDoc modeling for the as-designed footprints estimates annual removals of 101.5 pounds of total nitrogen, 6.08 pounds of total phosphorus, and 3.31 tons of total suspended solids. These are model estimates, not measured loads.

Wetland and pond plantings, 7,210 plants in all with 820 at the pond, were deferred to fall 2026 for survivability, with fewer and larger trees under a separate grant workplan; disturbed areas were stabilized and grassed in the meantime, and about 3.74 acres of alfalfa were replanted for the farm. Sustainable Science flew drone imagery of the finished site in October 2026 and is preparing a joint permit application to MDE for the remaining pond dredging and a beaver fence at the culvert mouth.