Assessment of Phosphorus Loads in Tile Drainage in the Jewett Brook Watershed of St. Albans Bay, Lake Champlain
Stone Environmental, Inc.(2019) Assessment of Phosphorus Loads in Tile Drainage in the Jewett Brook Watershed of St. Albans Bay, Lake Champlain, Grand Isle, VT: Lake Champlain Basin Program
Subsurface (tile) drainage is an essential water management practice on many agricultural fields in Vermont, allowing timely equipment access, reduced soil compaction, and increased crop yields in fields otherwise too wet to efficiently farm. Tile drainage can provide significant environmental benefits, from reduced soil erosion to more efficient nutrient uptake by crops to enabling more timely application of conservation measures, because producers face fewer delays due to wet field conditions. Tile drainage significantly alters field hydrology, reducing surface runoff but increasing subsurface discharge. Reports in the scientific literature suggest that discharge from subsurface drainage systems can be a significant source of phosphorus (P) to surface waters.
In Vermont and across the Lake Champlain Basin, little is known about the potential water quality impacts of agricultural tile drainage systems. To address this knowledge gap, the Project Team monitored representative tile drainage systems in the Jewett Brook watershed (JBW), a tributary to St. Albans Bay of Lake Champlain, estimated P loading from these tile drainage systems, and evaluated the significance of this loading to the overall P load from the JBW.
Data download includes monitoring and analysis data.