Residential and commercial land development comes with an entire slew of potential issues, not the least of which is stormwater runoff and potential damaging effects. Local, state, and federal regulations impose requirements on developers to plan for stormwater runoff when constructing developments to prevent future damage to structures, land, and surrounding areas. One of the most commonly used methods of preventing stormwater runoff and damage in modern developments is the use of man-made ponds; specifically, via detention and/or retention ponds.
Potential Damaging Effects of Stormwater Runoff
According to government climate data, New Hampshire receives more annual precipitation that average when compared to other states. Due to the climate of New Hampshire, this precipitation can come in several forms, including but not limited to rain, snow, and hail. If not adequately controlled, this precipitation can cause damaging effects to structures, land, and natural topographical features.
Specifically, in larger cities like Manchester and Concord, unchecked stormwater runoff can overwhelm public sewers and infrastructure. In smaller municipalities without municipal services, stormwater runoff poses threat of disaster to unpaved roads, delicate infrastructures like culverts, and undeveloped land. Natural bodies of water like streams and rivers can be adversely affected due to erosion and over-flooding. In essence, unchecked stormwater runoff can illustrate first hand the true devastating power water can have on human civilization.
Retention and Detention Ponds
One of the most common ways of controlling stormwater runoff is through the use of basins, also commonly referred to as ponds. While there are many different types of ponds used to control stormwater runoff, with new types and variations of ponds being developed all the time, the most commonly utilized ponds for development purposes are retention and detention ponds.
Retention ponds are man-made ponds that constantly maintain a water level but are designed with the ability to hold additional water like stormwater runoff. Retention ponds look like regular ponds, but are designed to retain and treat stormwater runoff. Generally, retention ponds capture stormwater runoff; use natural processes to remove pollutants from the runoff water; and then, via a network of pipes and infrastructure, slowly releases excess water to get back to its “standard” water level.
In contrast, detention ponds are not really ponds at all, but more accurately imagined as basins. Detention ponds do not maintain a constant water level; rather, detention ponds are designed to gather diverted stormwater into the basin and slowly drain the stormwater through an outlet (or outlets, in the case of larger detention ponds). In New Hampshire, detention ponds tend to be most appropriate for developments of large acreage, while retention ponds can be used in developments of any size.
In general, retention and detention ponds serve critical roles in controlling stormwater runoff in New Hampshire’s communities. As with all development infrastructure, retention and detention ponds should only be designed and constructed by licensed professions in conjunction with one another, typically designated as engineers, surveyors, and/or wetlands scientists. For more information on New Hampshire development, or for recommendations of professionals specializing in stormwater runoff management, please contact Liz Nolin, Esq. at (603) 227-6286 or liz@alfanolawoffice.com,