Low Impact Development Practices: Designing to Infiltrate in Urban Environments

Abstract

Low Impact Development (LID) is predicated on achieving a water balance for runoff, infiltration, and evapotranspiration. To meet infiltration needs associated with LID, many structural practices are used including: bioretention, infiltration trenches/wells, infiltrating wetlands, level spreader, vegetated filter strip systems, permeable pavement, swales, and water harvesting systems. Each of these practices can potentially infiltrate substantial amounts of runoff. Moreover, designers can alter these practice designs to increase infiltration volumes. Some design and construction features discussed in this chapter include the incorporation of sumps, or storage wells, in the bottom of LID infiltration practices and innovative means of excavation such that underlying soil saturated hydraulic conductivity is better preserved. An important concern for a system that relies on infiltration is whether the rate of infiltration is retained with time. A study at Villanova University indicated that while there is substantial infiltration rate fluctuation seasonally, there was no statistical evidence of annual infiltration rate decreasing. An examination of several types of permeable pavement systems in North Carolina showed that the type of permeable cover was not a factor in substantial and statistical runoff reduction. This allows LID designers to specify permeable pavement types based upon cost and 308 Effects of Urbanization on Groundwater Downloaded from ascelibrary.org by University of Illinois At Urbana on 10/08/15.

A Review of Permeable Pavement Clogging Investigations and Recommended Maintenance Regimes

“…LID and WSUD both aim to minimise the effects of urbanization by attenuating runoff peak flows and providing water quality control in order to protect downstream waterbodies, largely through mimicking natural processes [6,7]. Permeable pavements systems are able to both mitigate urban runoff [8] and to improve stormwater quality [9][10][11].…”

Optimal Planning of Low-Impact Development for TSS Control in the Upper Area of the Cau Bay River Basin, Vietnam

“…To deal with such an environmental issue, low impact development (LID) implementation has been considered an effective tool to remove pollutants of stormwater flow through detention, filtration, chemical adsorption, and biological processes [3]. LID is a green approach for managing both the quantity and quality of stormwater at a given site using decentralized micro-scale control measures [4,5].…”

Low Impact Development Practices: A Review of Current Research and Recommendations for Future Directions

“…Following LID goals and principles, there are large number of techniques generally classified as LID practices. Hunt et al [21,22] published examples of structural and nonstructural practices that promote these main goals of LID. Structural practices include bioretention, infiltration wells/trenches, stormwater wetlands, level spreaders, permeable pavements, green roofs, swales, vegetated filter/buffer strips, sand filters, smaller culverts, and water harvesting systems (rain barrels/cisterns).…”

“…Structural practices include bioretention, infiltration wells/trenches, stormwater wetlands, level spreaders, permeable pavements, green roofs, swales, vegetated filter/buffer strips, sand filters, smaller culverts, and water harvesting systems (rain barrels/cisterns). Nonstructural practices consist of minimization of site R e t r a c t e d Unauthenticated Download Date | 5/9/18 7:36 AM disturbance, preservation of natural site conditions and feature, reduction and disconnection of impervious surfaces (ie elimination of curbs and gutters), native vegetation utilization, soil amendment and aerification, strategic grading, and minimization of grass lawns [21,22]. LID encourages processes such as filtration, onsite storage and detention, infiltration, evapotranspiration, adsorption, biodegradation precipitation, and percolation, among others, which reduce the need for a centralized best management practice [7,23,24].…”

“…The main principles of LID are as follows [10,20]: Integrate stormwater management strategies in the early stage of site planning and design Manage stormwater as close to the source as possible with the some distributed micro-scale practices Encourage and implement environmentally friendly design Promote natural hydrological feature to create a hydrologic multifunctional landscape Mainly focus on prevention rather than mitigation and remediation Reduce costs for the construction and maintenance Empower communities and societies for environmental protection through public education and participation The main goals of LID practices and principles include runoff reduction (peak and volume), groundwater recharge, stream protection, increase infiltration and water quality assessment through the removal of different pollutants from the mechanism such as filtration, chemical sorption and other biological process [21]. Following LID goals and principles, there are large number of techniques generally classified as LID practices.…”