Low-impact development (LID) is a term used in Canada and the United States to describe a land planning and engineering design approach to manage stormwater runoff as part of green infrastructure . LID emphasizes conservation and use of on-site natural features to protect water quality . This approach implements engineered small-scale hydrologic controls to replicate the pre-development hydrologic regime of watersheds through infiltrating , filtering , storing, evaporating , and detaining runoff close to its source. Green infrastructure investments are one approach that often yields multiple benefits and builds city resilience.
41-569: (Redirected from Low Impact Development ) Low-impact development may refer to: Low-impact development (U.S. and Canada) , the term used in Canada and the US to describe planning and engineering design approach to managing stormwater runoff Low-impact development (UK) , the term used in the UK for developments with little or no environmental impact Topics referred to by
82-435: A piezometer . Aquifers are also described in terms of hydraulic conductivity, storativity and transmissivity. There are a number of geophysical methods for characterizing aquifers. There are also problems in characterizing the vadose zone (unsaturated zone). Infiltration is the process by which water enters the soil. Some of the water is absorbed, and the rest percolates down to the water table . The infiltration capacity,
123-410: A model and manage rainfall at the source is accomplished through sequenced implementation of runoff prevention strategies, runoff mitigation strategies, and finally, treatment controls to remove pollutants. Although Integrated Management Practices (IMPs) — decentralized, microscale controls that infiltrate, store, evaporate, and detain runoff close to the source — get most of the attention by engineers, it
164-402: A more global approach to the understanding of the behavior of hydrologic systems to make better predictions and to face the major challenges in water resources management. Water movement is a significant means by which other materials, such as soil, gravel, boulders or pollutants, are transported from place to place. Initial input to receiving waters may arise from a point source discharge or
205-451: A prediction in practical applications. Ground water is water beneath Earth's surface, often pumped for drinking water. Groundwater hydrology ( hydrogeology ) considers quantifying groundwater flow and solute transport. Problems in describing the saturated zone include the characterization of aquifers in terms of flow direction, groundwater pressure and, by inference, groundwater depth (see: aquifer test ). Measurements here can be made using
246-402: Is affected by the interaction of dissolved oxygen with organic material and various chemical transformations that may take place. Measurements of water quality may involve either in-situ methods, in which analyses take place on-site, often automatically, and laboratory-based analyses and may include microbiological analysis . Observations of hydrologic processes are used to make predictions of
287-445: Is an LID practice that facilitates the reuse of stormwater. There are 5 core requirements when it comes to designing for LID. Planning practices include several related approaches that were developed independently by various practitioners. These differently named approaches include similar concepts and share similar goals in protecting water quality. Planners select structural LID practices for an individual site in consideration of
328-769: Is an important part of the water cycle. It is partly affected by humidity, which can be measured by a sling psychrometer . It is also affected by the presence of snow, hail, and ice and can relate to dew, mist and fog. Hydrology considers evaporation of various forms: from water surfaces; as transpiration from plant surfaces in natural and agronomic ecosystems. Direct measurement of evaporation can be obtained using Simon's evaporation pan . Detailed studies of evaporation involve boundary layer considerations as well as momentum, heat flux, and energy budgets. Remote sensing of hydrologic processes can provide information on locations where in situ sensors may be unavailable or sparse. It also enables observations over large spatial extents. Many of
369-497: Is conducive to the generation of holistic policies, guidelines and regulations. Furthermore, the inclusion of UHI mitigation can be a driver to public participation in SPC construction, which can consolidate the PPP model for more funds. Hydrologic Hydrology (from Ancient Greek ὕδωρ ( húdōr ) 'water' and -λογία ( -logía ) 'study of')
410-508: Is crucial to understand that LID is more than just implementing a new list of practices and products. It is a strategic design process to create a sustainable site that mimics the undeveloped hydrologic properties of the site. It requires a prescriptive approach that is appropriate for the proposed land use . Design using LID principles follows four simple steps. The basic processes used to manage stormwater include pretreatment, filtration, infiltration, and storage and reuse. Pre-treatment
451-602: Is different from Wikidata All article disambiguation pages All disambiguation pages Low-impact development (U.S. and Canada) Broadly equivalent terms used elsewhere include Sustainable drainage systems (SuDS) in the United Kingdom (where LID has a different meaning ), water-sensitive urban design (WSUD) in Australia, natural drainage systems in Seattle , Washington, "Environmental Site Design" as used by
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#1732869884053492-489: Is only one of many important aspects within those fields. Hydrological research can inform environmental engineering, policy , and planning . Hydrology has been subject to investigation and engineering for millennia. Ancient Egyptians were one of the first to employ hydrology in their engineering and agriculture, inventing a form of water management known as basin irrigation. Mesopotamian towns were protected from flooding with high earthen walls. Aqueducts were built by
533-449: Is recommended to remove pollutants such as trash , debris , and larger sediments. Incorporation of a pretreatment system, such as a hydrodynamic separator , can prolong the longevity of the entire system by preventing the primary treatment practice from becoming prematurely clogged. When stormwater is passed through a filter media, solids and other pollutants are removed. Most media remove solids by mechanical processes. The gradation of
574-916: Is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle , water resources , and drainage basin sustainability. A practitioner of hydrology is called a hydrologist . Hydrologists are scientists studying earth or environmental science , civil or environmental engineering , and physical geography . Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation , natural disasters , and water management . Hydrology subdivides into surface water hydrology, groundwater hydrology ( hydrogeology ), and marine hydrology. Domains of hydrology include hydrometeorology , surface hydrology , hydrogeology , drainage-basin management, and water quality . Oceanography and meteorology are not included because water
615-580: Is thought of as starting at the land-atmosphere boundary and so it is important to have adequate knowledge of both precipitation and evaporation. Precipitation can be measured in various ways: disdrometer for precipitation characteristics at a fine time scale; radar for cloud properties, rain rate estimation, hail and snow detection; rain gauge for routine accurate measurements of rain and snowfall; satellite for rainy area identification, rain rate estimation, land-cover/land-use, and soil moisture, snow cover or snow water equivalent for example. Evaporation
656-513: Is utilized to formulate operating rules for large dams forming part of systems which include agricultural, industrial and residential demands. Hydrological models are simplified, conceptual representations of a part of the hydrologic cycle. They are primarily used for hydrological prediction and for understanding hydrological processes, within the general field of scientific modeling . Two major types of hydrological models can be distinguished: Recent research in hydrological modeling tries to have
697-618: The Greeks and Romans , while history shows that the Chinese built irrigation and flood control works. The ancient Sinhalese used hydrology to build complex irrigation works in Sri Lanka , also known for the invention of the Valve Pit which allowed construction of large reservoirs, anicuts and canals which still function. Marcus Vitruvius , in the first century BC, described a philosophical theory of
738-698: The Maryland Department of the Environment , and "Onsite Stormwater Management", as used by the Washington State Department of Ecology. A concept that began in Prince George's County , Maryland in 1990, LID began as an alternative to traditional stormwater best management practices (BMPs) installed at construction projects. Officials found that the traditional practices such as detention ponds and retention basins were not cost-effective and
779-399: The return period of such events. Other quantities of interest include the average flow in a river, in a year or by season. These estimates are important for engineers and economists so that proper risk analysis can be performed to influence investment decisions in future infrastructure and to determine the yield reliability characteristics of water supply systems. Statistical information
820-455: The 20th century, while governmental agencies began their own hydrological research programs. Of particular importance were Leroy Sherman's unit hydrograph , the infiltration theory of Robert E. Horton , and C.V. Theis' aquifer test/equation describing well hydraulics. Since the 1950s, hydrology has been approached with a more theoretical basis than in the past, facilitated by advances in the physical understanding of hydrological processes and by
861-550: The U.S. Environmental Protection Agency (EPA) and is being promoted as a method to help meet goals of the Clean Water Act . Various local, state, and federal agency programs have adopted LID requirements in land development codes and implemented them in public works projects. LID techniques can also play an important role in Smart Growth and Green infrastructure land use planning. The basic principle of LID to use nature as
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#1732869884053902-483: The University of Maryland, College Park conducted research on the runoff management from LID rain gardens. His data indicated that LID rain gardens can hold up to 90% of water after a major rain event and release this water over a time scale of up to two weeks. LID also improves groundwater quality and increases its quantity, which increases aesthetics, therefore raising community value. LID can also be used to eliminate
943-560: The advent of computers and especially geographic information systems (GIS). (See also GIS and hydrology ) The central theme of hydrology is that water circulates throughout the Earth through different pathways and at different rates. The most vivid image of this is in the evaporation of water from the ocean, which forms clouds. These clouds drift over the land and produce rain. The rainwater flows into lakes, rivers, or aquifers. The water in lakes, rivers, and aquifers then either evaporates back to
984-530: The atmosphere or eventually flows back to the ocean, completing a cycle. Water changes its state of being several times throughout this cycle. The areas of research within hydrology concern the movement of water between its various states, or within a given state, or simply quantifying the amounts in these states in a given region. Parts of hydrology concern developing methods for directly measuring these flows or amounts of water, while others concern modeling these processes either for scientific knowledge or for making
1025-434: The benefits of infiltration include improved water quality (as water is filtered through the soil) and reduction in runoff. When distributed throughout a site, infiltration can significantly help maintain the site's natural hydrology. Capturing and reusing stormwater as a resource helps maintain a site's predevelopment hydrology while creating an additional supply of water for irrigation or other purposes. Rainwater harvesting
1066-685: The future behavior of hydrologic systems (water flow, water quality). One of the major current concerns in hydrologic research is "Prediction in Ungauged Basins" (PUB), i.e. in basins where no or only very few data exist. The aims of Statistical hydrology is to provide appropriate statistical methods for analyzing and modeling various parts of the hydrological cycle. By analyzing the statistical properties of hydrologic records, such as rainfall or river flow, hydrologists can estimate future hydrologic phenomena. When making assessments of how often relatively rare events will occur, analyses are made in terms of
1107-461: The hydrologic cycle, in which precipitation falling in the mountains infiltrated the Earth's surface and led to streams and springs in the lowlands. With the adoption of a more scientific approach, Leonardo da Vinci and Bernard Palissy independently reached an accurate representation of the hydrologic cycle. It was not until the 17th century that hydrologic variables began to be quantified. Pioneers of
1148-430: The important areas of hydrology is the interchange between rivers and aquifers. Groundwater/surface water interactions in streams and aquifers can be complex and the direction of net water flux (into surface water or into the aquifer) may vary spatially along a stream channel and over time at any particular location, depending on the relationship between stream stage and groundwater levels. In some considerations, hydrology
1189-403: The maximum rate at which the soil can absorb water, depends on several factors. The layer that is already saturated provides a resistance that is proportional to its thickness, while that plus the depth of water above the soil provides the driving force ( hydraulic head ). Dry soil can allow rapid infiltration by capillary action ; this force diminishes as the soil becomes wet. Compaction reduces
1230-675: The media, irregularity of shape, porosity, and surface roughness characteristics all influence solids removal. Many other pollutants such as nutrients and metals can be removed through chemical and/or biological processes. Filtration is a key component to LID sites, especially when infiltration is not feasible. Filter systems can be designed to remove the primary pollutants of concern from runoff and can be configured in decentralized small-scale inlets. This allows for runoff to be treated close to its source without additional collection or conveyance infrastructure. Infiltration reclaims stormwater runoff and allows for groundwater recharge . Runoff enters
1271-511: The modern science of hydrology include Pierre Perrault , Edme Mariotte and Edmund Halley . By measuring rainfall, runoff, and drainage area, Perrault showed that rainfall was sufficient to account for the flow of the Seine. Mariotte combined velocity and river cross-section measurements to obtain a discharge value, again in the Seine. Halley showed that the evaporation from the Mediterranean Sea
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1312-625: The need for stormwater ponds, which occupy expensive land. Incorporating LID into designs enables developers to build more homes on the same plot of land and maximize their profits. In some municipalities, LID can be a cost-effective way to reduce the incidence of combined sewer overflows (CSO). According to the co-benefits approach, LID is an opportunity to technically mitigate urban heat island (UHI) phenomenon with higher compatibilities in cool pavement and green infrastructures. Although there are some intrinsic discrepancies among understandings of LID and UHI mitigation towards blue infrastructure,
1353-461: The osmotic pool, wet pond, and regulating pond are essential supplements to urban water bodies, performing their roles in nourishing vegetation and evaporating for cooling in UHI mitigation. LID pilot projects have already provided the financial foundation for taking the UHI mitigation further. It is an attempt for people in different disciplines to synergistically think about how to mitigate UHI effects, which
1394-461: The porosity and the pore sizes. Surface cover increases capacity by retarding runoff, reducing compaction and other processes. Higher temperatures reduce viscosity , increasing infiltration. Soil moisture can be measured in various ways; by capacitance probe , time domain reflectometer or tensiometer . Other methods include solute sampling and geophysical methods. Hydrology considers quantifying surface water flow and solute transport, although
1435-528: The results did not meet water quality goals. The Low Impact Development Center, Inc., a non-profit water resources research organization, was formed in 1998 to work with government agencies and institutions to further the science, understanding, and implementation of LID and other sustainable environmental planning and design approaches, such as Green Infrastructure and the Green Highways Partnership. The LID design approach has received support from
1476-440: The same term [REDACTED] This disambiguation page lists articles associated with the title Low-impact development . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Low-impact_development&oldid=676229125 " Category : Disambiguation pages Hidden categories: Short description
1517-689: The site's land use , hydrology , soil type, climate and rainfall patterns. There are many variations on these LID practices, and some practices may not be suitable for a given site. Many are practical for retrofit or site renovation projects, as well as for new construction. Optimal places for retrofitting LID are single houses, school/university areas, and parks. Frequently used practices include: Urban areas are especially prone to create barriers for LID practices. The most common limits are: LID has multiple benefits, such as protecting animal habitats, improving management of runoff and flooding, and reducing impervious surfaces. For example, Dr. Allen Davis from
1558-483: The soil and percolates through to the subsurface. The rate of infiltration is affected by soil compaction and storage capacity, and will decrease as the soil becomes saturated. The soil texture and structure, vegetation types and cover, water content of the soil, soil temperature, and rainfall intensity all play a role in controlling infiltration rate and capacity. Infiltration plays a critical role in LID site design. Some of
1599-440: The treatment of flows in large rivers is sometimes considered as a distinct topic of hydraulics or hydrodynamics. Surface water flow can include flow both in recognizable river channels and otherwise. Methods for measuring flow once the water has reached a river include the stream gauge (see: discharge ), and tracer techniques. Other topics include chemical transport as part of surface water, sediment transport and erosion. One of
1640-604: The variables constituting the terrestrial water balance, for example surface water storage, soil moisture , precipitation , evapotranspiration , and snow and ice , are measurable using remote sensing at various spatial-temporal resolutions and accuracies. Sources of remote sensing include land-based sensors, airborne sensors and satellite sensors which can capture microwave , thermal and near-infrared data or use lidar , for example. In hydrology, studies of water quality concern organic and inorganic compounds, and both dissolved and sediment material. In addition, water quality
1681-603: Was sufficient to account for the outflow of rivers flowing into the sea. Advances in the 18th century included the Bernoulli piezometer and Bernoulli's equation , by Daniel Bernoulli , and the Pitot tube , by Henri Pitot . The 19th century saw development in groundwater hydrology, including Darcy's law , the Dupuit-Thiem well formula, and Hagen- Poiseuille 's capillary flow equation. Rational analyses began to replace empiricism in