U&A has restored a one mile reach of an urban stream, retrofit stormwater ponds with impervious areas that exceeded 40% and removed a dam to restore streams and associated wetlands in a 13 square mile drainage area. But one of the most challenging, yet immensely rewarding, project we successfully realized was a design and build effort for a therapeutic riding horse farm whose mission is to improve the quality of life of adults and children with disabilities.
Maryland Therapeutic Riding (MTR) has a 26-acre drainage area and occupies the lowest part of the landscape with three sides of the property draining toward their buildings. The property was once a sand mine that buried the existing stream on site and drains into a very shallow sloped, slowly flowing stream, causing stormwater to regularly flood poorly situated arenas and paddocks and barely drain the property. Prior to the project, flooding regularly limited the accessibility of various locations on the property, causing repeated cancellations of classes, and contributed to damaging the buildings’ foundations.
During the design phase, U&A Principal and staff attended numerous committee meetings that involved the Executive Director, Program Director, Development Director, Board Members, among others to understand the client’s myriad needs for the safety of the riders with disabilities as well as the horses. Through a year long process, U&A addressed MTR’s concerns and incorporated many of their comments into the RSC design while maintaining the integrity of an RSC approach. U&A successfully developed viable solutions to address four challenging design goals: 1) reduce flooding, especially the indoor arena, from regular storm events; 2) meet the water quality improvement requirements of the grant; 3) meet the needs and precautions for their special needs clients and specially managed herd; and 4) reduce the footprint of the open water stormwater channel as much as possible in order to reduce encroaching on paddocks, access roads and paths.
The design, true to RSC, did not simply remove stormwater off site. Although concessions to losing small areas of a few paddocks and paths needed to be made by the client, the U&A designed system captured stormwater on site and directed it through a series of sand bedded channels, pools, weirs and berms to infiltrate a significant portion of the incoming water throughout the system, thereby recharging the groundwater table, allowing sedimentation, regulating temperature and utilizing biogeochemical processes to break down nutrients. The open channel design that simulates a natural stream, also allows for evapotranspiration, which underground pipes cannot. Conventional stormdrain pipe network would present sell on paper, but in reality it would have been exacerbated the problem by channeling large volumes of stormwater to the receiving stream that does not have the capacity to handle such volumes and thereby degrading the stream with erosive forces, backwatering a greater portion of the property and flooding the downstream property.
Construction phase also required close communication and coordination with MTR’s Caretaker, Barn Manager and Groundskeeper to work around horse trainings, morning and evening pasture/boarding transition times, lessons, etc. U&A worked around the various schedules, through Christmas and New Year’s to complete construction on time before winter class sessions resumed and modified few construction practices to reduce stress on the horses. Post construction, U&A and MTR observed a few large storm events and returned to make modifications, which had been suggested by U&A prior to the completion of construction but cautiously rejected by MTR at the time, to further increase infiltration and reduce flooding.
By utilizing both lateral and vertical hydrologic gradients and working close with MTR staff and board members, the design and construction significantly reduced flooding of the buildings, volume of stormwater runoff exiting the property, improved the water quality of the tributary to the Severn River, protected one of the last remaining bogs in the county from getting washed out and silted, and maintained the safety of the riders and horses.
Maryland Therapeutic Riding Center, a non-profit organization who seeks to help children and adults with physical, mental, and emotional disabilities through therapeutic riding and horse aided therapies. The farm consists of an indoor arena, two outdoor riding areas, two barns and nine paddock. A lack of storm water management for the property has caused several problems impacting the non-profits programs. In addition, Arden bog, a very important unique ecosystem identified by the Department of Natural Resources, sits a mere mile from the farm collecting uncontrolled storm water runoff. Underwood & Associates has designed a drainage enhancement system and will build a RSC creating 0.75 aces of retention area, 1 acre of grasslands and nearly and constructing 1,600 linear feet of regenerative open-channel system that converts storm flows to shallow groundwater flows. The project goal is to reduce the potential for flooding the buildings and paddocks on the site, and to leverage storm water to create high quality wetland habitat and enhance ecosystem services on site.
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