By Paul Kwiatkowski
Water Quality Mount Auburn Cemetery has four significant water bodies within its 175-acre property . This includes three small ponds and a vernal pool . The ponds are permanently flooded features in the landscape and the vernal pool is a seasonal flooded depression that may completely lack surface water during droughty periods that can last past late summer and into autumn .
All the water bodies are shallow with considerable layers of organic material accumulated at each pond bottom . The three ponds are connected to the underground water catchment system and there are multiple culverts that carry stormflow into the ponds . The vernal pool is not connected to the catchment system and receives storm inputs only through direct rainfall and sheetflow that may contain organic material washed from the slopes of the hollow in which the pool is located .
Figure 1 – This image of a Great Blue Heron dining on a fish is an indicator that Mount Auburn ’ s long-term plan to monitor water quality and improve the overall health of each pond is working .
Organic material does not build up from storm discharge alone . The primary source is the vegetation that surrounds each water body . Leaves and small limbs fall , then sink through the water column and accumulate over time , reducing the depths of the ponds . The storm water and the accumulating sediment impact the waterbodies in negative ways . The stormflow carries harmful , nutrient-laden sediment from the cemetery ’ s roads that is rich in phosphorus and nitrogen . In large enough amounts , each can harm water quality . The loss of pond depth allows the water temperature to warm more quickly which can aid algae growth and impact the amount of available oxygen for fish , amphibians and reptiles .
Mount Auburn has a long-term plan in place to monitor water quality and improve the overall health of each pond . This includes strategies both outside of and inside of the water bodies . The outside efforts include annual street sweeping every spring to remove sands put down during winter storms and cleaning out catch basins throughout the cemetery . These actions reduce sediment entering the ponds . The areas surrounding each waterbody are restricted from fertilizer applications . This also helps reduce excessive nitrogen and phosphorus inputs . The inside efforts include aeration systems to improve oxygenation and the creation of emergent shelves along the shallow pond edges , near storm drainpipes , to allow for sedimentation and for emergent plants to take up and sequester harmful nutrients through their root systems , which protects aquatic habitat for wildlife .
Mount Auburn Cemetery | Climate Action & Sustainability Plan 44