eastern washington low impact development guidance manual
LINK 1 ENTER SITE >>> Download PDF
LINK 2 ENTER SITE >>> Download PDF
File Name:eastern washington low impact development guidance manual.pdf
Size: 4487 KB
Type: PDF, ePub, eBook
Category: Book
Uploaded: 22 May 2019, 19:25 PM
Rating: 4.6/5 from 590 votes.
Status: AVAILABLE
Last checked: 9 Minutes ago!
In order to read or download eastern washington low impact development guidance manual ebook, you need to create a FREE account.
eBook includes PDF, ePub and Kindle version
✔ Register a free 1 month Trial Account.
✔ Download as many books as you like (Personal use)
✔ Cancel the membership at any time if not satisfied.
✔ Join Over 80000 Happy Readers
eastern washington low impact development guidance manualCommon LID practices include: bio-retention, rain gardens, permeable pavements, minimal excavation foundations, vegetated roofs, and rainwater harvesting. We partnered with Washington State University to develop a joint Washington State LID Certificate Program. The program offers two certificate tracks: What was challenging.Your name: Phone number. These low impact development techniques strive to mimic pre-disturbance hydrological processes by emphasizing site conservation, use of on-site natural features, site planning, and distributed stormwater management practices. This guidance manual addresses general requirements and may be modified or supplemented in other specific sections. This reference is on file with the director. Compliance with the Basic Requirements of the Spokane Regional Stormwater Manual shall be met regardless of best management practices used. Certain low impact development techniques may be used to fulfill the basic requirements set forth in the Spokane Regional Stormwater Manual, as approved by the director. Rain gardens do not necessarily meet basic requirements and can be used where basic requirements do not apply. A supplemental resource to the Eastern Washington Low Impact Development Guidance Manual is the Washington Stormwater Center. Stormwater is regulated under the federal Clean Water Act administered in Washington State by the Department of Ecology. Under Department of Ecology’s direction, cities and counties are required to integrate Low Impact Development (LID) into their local development and re-development regulations when they update them. Western Washington will require the use of LID for new development and redevelopment and Eastern Washington will allow the use of LID. Implementation of regulations will be come between 2015 and 2018 with most cities and counties implementing new regulations by December 2016. What does this mean for landscapers and nurseries.http://www.fototapetki.pl/upload/images/creative-zen-1gb-stone-manual.xml
- Tags:
- eastern washington low impact development guidance manual, eastern washington low impact development guidance manual, eastern washington low impact development guidance manual pdf, eastern washington low impact development guidance manual 6th edition, eastern washington low impact development guidance manual transmission, eastern washington low impact development guidance manual 2017.
Stormwater will increasingly be managed with LID rather than conventional management techniques. LID strives to mimic pre-developed drainage by using on-site natural features, site design, and runoff distribution. LID strategies include bioretention like rain gardens, permeable pavements, runoff dispersion through natural vegetation, and restoration of soil quality and depth. Get involved ! Provide ideas to your local leaders as they develop new policies encouraging or requiring LID. M unicipal Research and Services Center of Washington, provides information on city and county officials in the planning department to make contact with in regard to LID. Low Impact Development Resources Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia and Alaska. Lone Pine Publishing, 1994. The webinars also included information about upcoming regulatory changes that will increase the use of LID, the schedule for regulatory implementation, the opportunities for landscape and nursery professionals, and how to prepare. The webinars included presentation and discussion from experienced landscape, nursery and industry professionals. Webinar presenters discuss techniques for selecting plants, broadening the plant palette and growing native plants appropriate for LID in a nursery setting. Ballek specializes in seed collection, plant propagation, development of innovative restoration techniques, wetland mitigation, stream bank stabilization, erosion control, habitat enhancement, exotic vegetation control, out-planting techniques and success monitoring. www.herrerainc.com Ever wonder what the difference is between rain gardens and bioretention facilities. Presenters explain the differences of these two types of LID facilities along with their structure and maintenance requirements, and present experience and insight on preparing your business to install and maintain rain gardens as well as market them.http://l-max.ru/userfiles/creative-zen-4gb-manual-pdf.xmlHe currently serves on the technical advisory committee for the 2012 Eastern Washington LID manual and was on the Advisory Committee of the 2005 LID Technical Guidance Manual for Puget Sound. Some of his notable projects include the Stillaguamish Department of Natural Resources offices and water quality lab—Arlington, WA and Taylor 28 Apartments, rainwater reuse, pervious pavement, and rain gardens—Seattle, WA. Before starting her business, Jessi organized restoration projects with community volunteers for the King Conservation District. Jessi has designed and installed hundreds of rain gardens including King County’s largest residential rain garden in Kirkland. She teaches rain garden workshops to professionals and homeowners for Washington State University Extension, Seattle Public Utilities and at the North West Garden Show. Jessi is now a best-selling author of Free Range Chicken Gardens (Timber Press 2012) and is co-author of The Wetland Handbook: A Community Guide to Growing Native Plants (King Conservation District). www.nwbloom.com Permeable pavements have the potential to play a major role in slowing and preventing stormwater runoff. This webinar describes the products available, their structural requirements and the experiences of a landscape professional incorporating permeable pavements into their business. His current responsibility is to provide masonry and hardscape system information to Puget Sound design professionals. Rick has been a nationally respected instructor of quality assurance and special masonry inspection using curriculum developed by The Masonry Society (TMS). Rick holds a Bachelor of Science degree in Civil Engineering from the University of Utah. She teaches horticulture at Edmonds Community College. She is an award winning landscape designer, certified Low-Impact-Development (LID) designer and construction consultant, wetland delineator, certified professional horticulturist, certified tree risk assessor, and a certified arborist.http://fscl.ru/content/bose-wave-radio-cd-manual-pdf As a consultant, she often works with bioretention solutions, vegetated roofs, living walls, edible gardens and integrated design principles. Zsofia is the past-president of the Sustainable Development Task Force of Snohomish County (SDTF), a member of the Rain Garden Coalition of Snohomish County, on the Sno-King Watershed Council and a member of the Curriculum Board for Edmonds Community College. CERTIFICATION Certified Professional Horticulturist ecoPRO Sustainable Landscape Professional. In addition to the demonstration project, a Regional LID Manual (PDF) was developed. Both are funded by a grant from the Washington state Department of Ecology with 25 matching funds from Yakima County. The goal of using LID is to mimic a site's predevelopment hydrology by choosing design techniques that infiltrate, filter, store, evaporate, and detain runoff close to its source. LID practices include vegetated swales, permeable pavements, “green roofs” and “rain gardens.” Design guidance and examples of LID methods are limited in semi-arid areas with dry summer - cold winter climates. Research shows that LID benefits are most effective in low and moderate rainfall conditions like those in Yakima. Demonstrating the effectiveness of LID infiltration practices such as porous pavements and amended soil bioswales would provide tangible evidence that LID is achievable in the local climate. These practices will help improve water quality problems of fecal coliform and elevated metals in an area with ESA listed fish species. Demo Project This demonstration project will validate the use of infiltration practices in the Yakima area, thus reducing stormwater runoff pollutant loading, and improving water quality. This project will be implemented from January 1, 2010 and completed December 31, 2014. We have been pioneering advancements in this field since 1993 and bring unparalleled experience in sustainable policy development and design.https://abcdedektor.com/images/canon-super-g3-manual.pdf Our multidisciplinary firm offers a rare perspective of sustainability from both sides of the table. We have not only authored countless code amendments to encourage or require the use of LID, we have also implemented sustainable design solutions in both public and private projects across the state. In fact, our work is referenced as official guidance in Western Washington’s Phase I and Phase II Municipal Stormwater Permits and California’s statewide NPDES Municipal Stormwater Permit. We strive to achieve our client’s goals within the boundaries of the code requirements by using the right mix of traditional and sustainable design solutions. Our firm embraces a responsibility to contribute to our region through projects that foster environmental health and vitality. Our professional contributions include: AHBL's Seattle office even resides in the Park Place Building, Seattle's first existing building awarded the LEED-EB Platinum Certification. AHBL's corporate activities include. It can protect aquatic resources, water quality, and the natural hydrology of a watershed as development takes place.The water then spread out over the forest floor, where it is absorbed into the ground, taken up by the roots of trees and other plants, or evaporated. However, when forests and natural open spaces are cleared, and buildings, roads, parking areas and lawns dominate the landscape, rainfall becomes stormwater runoff, carrying pollutants to nearby waters. Much less stormwater infiltrates and is taken up by plants, less stormwater evaporates back to the atmosphere, and much more stormwater becomes surface runoff.This ensures that our resources remain clean and Puget Sound remains a great place to operate a business and attract employees. Taxpayers don’t have to pay for expensive cleanup efforts for polluted waters and sediments.This replenishes groundwater and helps reduce the increase flow to small creeks during rain events. The pervious pavement reduces the amount of storm runoff by allowing rain to infiltrate through the surface and into the ground. Nutrients in the composted soils work to break down and remove pollutants from the runoff. Most of this information includes permeable and porous pavements as part of their best management practices. We've done the research for you and provide a number of these here for your easy reference. We will add new information as it becomes available, so check back for new entries. The information is listed by state name. For a list of these programs, click here. The difference? Stormwater planters are contained in structures made of a durable material, such as plastic-lined wood, stone, brick, or concrete. Stormwater planters have been described as “rain gardens in a box.” Water may then be allowed to infiltrate (seep) into the soil, or it may be conveyed to another approved disposal point. Infiltration planters cleanse, detain, and reduce runoff volumes by allowing water to soak into the surrounding soils. By contrast, filtration planters cleanse and detain stormwater runoff and then pipe the water off-site. They do not allow infiltration and do not significantly reduce stormwater volumes. In fact, they are lined specifically to prevent infiltration in unsafe conditions. They are also often built on private sites where space available for stormwater management is limited. The main drawback is that the vertical sides must be constructed out of concrete, wood, or some other material, which costs more to build. Potential areas for planters include front and back residential yards, parking lots, and streets (Barr 2001). Because of their flexible location requirements and range of designs, planters can add aesthetic appeal to a landscape, and can also attract wildlife (LCREP 2006). Planters can also fulfill certain landscaping requirements on a site. Storing runoff within the planter allows sediments and pollutants to settle out. Plantings also clean water through a process known as bioretention. Infiltration planters effectively reduce stormwater flow rates and volumes, which decreases the amount of runoff and pollutants entering waterways. Runoff itself was reduced by an estimated 40 to 80 percent. Find more information on pollutant removal in table SQ-6 in the Urban Drainage and Flood Control District’s Drainage Criteria Manual (UDFCD 2008). The structural requirement of creating vertical walls makes this system one of the most expensive facilities to build. Filtration planters are more costly than infiltration planters, due to piping requirements and waterproofing concerns, since they are often constructed close to buildings or other structures. Rock mulch costs more up front than compost mulch and is more expensive to maintain. Impervious surfaces generate the most runoff; simple landscapes such as lawn generate a moderate amount of runoff; and complex garden areas with trees, shrubs, and mulch generate the least, if any, runoff. Ponding depth is typically 12 inches between the top of the amended planting soil and the overflow outlet (DES and CEDD 2007, BES 2016). The slope of the bottom of the facility should not exceed 0.5 percent (LCREP 2006). According to Oregon law, if you exceed this measurement, you must include a handrail or some other barrier adequate for fall protection. Check with your local planning department for design requirements specific to your area. Rainfall patterns vary, over time, in volume and intensity. To help quantify these patterns, it’s helpful to understand the concepts of a “design” storm and rainfall distribution. A “design” storm is a theoretical storm that facilities such as stormwater planters are designed to treat. The size of the storm is analyzed to occur at a given frequency. They are described as 6-month, 1-year, 2-year, 25-year, or 100-year storms that occur over a 6-hour or 24-hour period. The size and duration of the design storm is typically specified by local regulations. In Oregon, this is a 24-hour design storm somewhere between 1 and 2 inches. Even if a jurisdiction requires infiltration of the 25-year storm event, stormwater planters are still a good choice as long as soils drain reasonably well. Table 1 (page 5) shows approximately how large a 12-inch deep stormwater planter would need to be in cities around Oregon, assuming a drainage area of 10,000 square feet and a design infiltration rate of 2 inches per hour. These distributions provide a way to model the intensity and duration of rainfall for a given design storm. Oregon has three different rainfall distributions, called Type IA, Type I, and Type II. Type IA is a lower intensity, longer duration storm typical of western Oregon, while Type II storms are higher intensity, shorter duration storms. Type I storms fall in between these two. Each jurisdiction will develop its own requirements for the size of storm (design storm) and distribution type (1A, 1, and II) based on goals for water quality and quantity. The suggested minimum width for infiltration stormwater planters is 24 inches, measured within the walls (BES 2016). These sizing recommendations ensure that they will drain in time to treat the next storm, provide drainage for plants, and prevent the accumulation of standing water (a draw for mosquitoes and other pests). Peak flows from the 25-year storm event can be infiltrated in cost-effective facilities throughout the state, regardless of whether your jurisdiction experiences the gentle, frequent Type IA storm distribution or the less frequent, more intense Type II storms, or something in between. Keep in mind that most jurisdictions do not require treatment of that large of a storm (a 25-year storm), so if the design storm is smaller, then the facility footprints illustrated in Table 1 might be larger than your final design. (See the column labeled “Stormwater planter footprint needed.”) Some regulations vary for other reasons. For example, the Central Oregon Stormwater Manual requires the area of the planter to be based on storing the volume of the entire water quality storm—a much shallower and more frequent storm than the 25-year, 24-hour design storm—since the soil may be frozen and unable to infiltrate during some storms. Given the same set of variables, these planters will be larger than those shown in Table 1. If the facility cannot be sized to accommodate the required runoff volumes, place a 12-inch layer of washed drain rock beneath the infiltration planter. See page 8 for recommendations on designing an infiltration planter to avoid triggering state underground injection control (UIC) requirements. In situations where water should be prevented from infiltrating the underlying soils, use an impermeable liner along the bottom of the facility. These liners typically consist of 60-mil PVC (DES and CEDD 2007), but 30-mil polyethylene pond liners and bentonite clay mats can be just as effective. As in infiltration planters, the suggested minimum width is 18 inches, measured within the walls (BES 2008). Typically, a 12-inch layer of ?-inch open-graded (that is, all the same or of very similar diameter), washed, crushed aggregate is used in combination with a perforated, 4-inch HDPE (high-density polyethylene) pipe to allow for detention and conveyance of the water (Gresham 2007). The City of Portland recommends a layer of ?- to ?-inch washed, crushed rock between the soil medium and gravel layer to prevent soil from mixing with the drain rock (BES 2008). However, studies indicate a detention time of only 13 minutes and a reduction in volume of only 20 percent for ?-inch, 24-hour storms in our rainy season’s early storms, when soils are not saturated (Yeakley 2010). Thus, it may not be advisable to rely on filtration planters for flow control or detention purposes. If not required, we recommend using washed, crushed rock to limit the amount of “fines” (silt, fine sand) that are transported and could clog a geotextile. Clogged geotextile fabrics keep stormwater from reaching the gravel layer below and inhibit proper flow out of the facility, causing the plants to have constant “wet feet.” Designers can slow the water a little by installing a narrow, French drain underdrain rather than installing gravel across the entire bottom of the facility. Infiltration planters also use native, uncompacted soils at the base. Many planter details call for a 2-inch layer of bark mulch to cover the facility. However, this material can float and leave soil bare, even during small storms that simply redistribute the mulch around the garden; large storms may carry it right out through the overflow structure. As mulch breaks down, the amount of available oxygen in the downstream water body can decrease. For this reason, use a 2-inch layer of coarse compost or arborist wood chips in lieu of bark mulch in the regularly inundated area. Above the regularly inundated area, either continue with coarse compost or switch to fine compost. Consider adding mycorrhizae (that is, live mushroom soil additive, not mushroom compost) to the soil, which grow into the compost and form a mat of mycelium, or mushroom roots, that hold it together and keep it from floating. The most effective way to control erosion is to plant dense vegetation on the bottoms of the facilities, and reserve the use of mulch for the time of construction. Dense plantings also shade out most weeds. Avoid rock mulch, which is expensive and difficult to maintain without causing the rocks to settle into the growing medium. The placement of rock mulch at the inlet and outlet is also inadvisable, since high water flows bury it in sediment and transport smaller rocks, up to 2 inches in diameter, around the facility, leaving soil bare. The ideal infiltration rate is between.The top 18 inches of soil is typically amended with organic compost. In some cases, existing topsoil is replaced with a soil mix, as specified by the local jurisdiction. Avoid mixes that are so sandy that they do not have enough organic matter to adequately support plant life, which increases irrigation and fertilization needs and the likelihood the plants will die. Also, be careful to use soil and compost that are free of weed seeds.The effective infiltration rate of the facility is defined by the area available for infiltration: The larger the infiltration area, the lower the soil’s infiltration rate can be while still managing the required storm. Most jurisdictions recommend at least.Since stormwater has already passed through the middle, 18-inch-deep amended soil layer and received treatment, there is no recommended maximum infiltration rate for native soils. If infiltration rates are so low that the plants will be inundated for too long, consider using an infiltration stormwater planter with an underdrain. Install it so it’s raised a few inches above the bottom of the drain rock to allow some water to infiltrate out the bottom of the facility. Even a little infiltration helps improve water quality and reduce downstream flooding, but be aware that underdrains are notorious for exporting nitrogen and phosphorus, which cause algae blooms. For this reason, a planter with a bigger area and smaller ponding depth is a better choice than an underdrain. However, this practice is questionable, especially if the storage rock is separated from the surrounding native soil by a geotextile fabric, which can clog. Instead of a fabric, use a granular subbase material meeting gradation requirements of AASHTO 3 or 4 aggregate, which is a specification for uniformly graded gravel (UDFCD 2008). Avoid rounded river rock, which is usually mined out of riverbeds in Oregon; mining activities damage those waterways. To make full use of this benefit, a facility designed with more plants will result in greater treatment capacity. Plant densely to maximize runoff treatment and control weeds; aim for 90 to 95 percent coverage within two to three years. Local jurisdictions often provide specifications for density, size, and types of vegetation. Choose plants based on their tolerance to flooding and ability to survive in local climate conditions with no fertilizers, herbicides, or insecticides. Plants should also be able to survive with minimum to no watering after establishment, which usually occurs in three years. Perennial flowers, ornamental grasses, and shrubs can add significant appeal. Planters can also be designed to attract beneficial insects and wildlife. Contact your local OSU Extension Service office or planning department for a list of plants appropriate for your area. Floods can carry weed seeds downstream to natural wetlands. A list of noxious weeds is available on the Oregon Department of Agriculture’s website (ODA 2007). Nonnative seeds and rhizomes can greatly impact the habitat potential and hydrology of our natural waterways. In addition, native plants support native microbes and other native soil life and are a better food source for native insects and birds. If your jurisdiction does not have plant recommendations, contact the local soil and conservation district or visit the USDA PLANTS database (plants.usda.gov) and use the Advanced Search option to generate your own list. The Washington Department of Ecology provides an extensive list of plants adapted for climates east of the Cascades (WDOE 2013). In these cases, choose salt-tolerant, non-woody species (EPA 2013.) Beehive grates or U-shaped overflows make good overflow devices because they are less likely to clog than a flat catch-basin grate, but the U-shaped grates are commonly placed at too high an elevation. Make sure that if you use this system, the bottom of the pipe, not the top, is set to ensure adequate freeboard of at least 2 inches below the top of the facility. Another strategy when a standard catch basin is already available in the street is to direct overflows safely to the public right-of-way via a weir or berm. Regardless, overflow should drain to an approved disposal point. This perforated pipe allows water to drain through and be treated by the soil column and then conveyed away so plants do not become waterlogged. If the facility is lined, the perforated pipe is completely enclosed in the facility and cannot infiltrate to the native soils, and so is not regulated as an Underground Injection Control (UIC). Perforated pipes that do not drain to an approved disposal point, such as a surface infiltration facility or a nonperforated pipe, may trigger UIC requirements and are reviewed on a case-by-case basis. Private facilities require cast-iron ABS SCH40, or PVC SCH40 (BES 2016). Outlet size should be selected to drain the planter over 12 hours or more (UDFCD 2008) and should be of sufficient diameter that it can be cleaned and maintained with the equipment available. Since we rely on the native subgrade soils to infiltrate stormwater, use orange protection or chain-link fence to mark planter areas off-limits to construction traffic and stockpiling activities. Use construction techniques that protect the soils during excavation, such as track equipment or excavating from the sides of the infiltration area. If the soils are exposed to rain, fine soil particles that may clog the native subgrade soils will be picked up and moved around. On a dry day, rake the surface to a depth of 3 inches to loosen soil before proceeding, or fold a few inches of compost into 8 to 12 inches of soil using a garden spade. Next, install the storage rock, if needed. Place the planting medium in 6-inch lifts and compact it lightly with boot tamping or water compaction to avoid settlement after the first storm. Never use vibratory compaction, which could negatively impact the many benefits the soil provides. Give plants at least three months to establish themselves before allowing stormwater to flow to the facility. Given this time, the plant roots will have a better hold on the soil, decreasing the effects of erosion, and increasing the odds that the plants will grow and thrive. If properly maintained, a stormwater planter can last indefinitely (Barr 2001). If the facility receives large volumes of silt and clay during storms, or small volumes over time, it could become clogged. Use a pretreatment structure at the inlet to settle out sediments before stormwater enters the facility. Plants may need frequent watering and weeding to survive Oregon’s dry summers until they are well established and cover at least 90 percent of the bottom of the facility. Maintenance needs taper off dramatically if you choose plants that require little to no watering after establishment and tolerate flooding conditions. Keep weeds down by providing only the amount of irrigation needed, and no more. Because these systems are not very effective at treating soluble pollutants such as nitrogen and phosphorous, practice integrated pest management. Do not use herbicides or pesticides in the facility itself. Find out if there are any maps, as-built drawings, or site-specific constraints. In many cases, when building a planter on a nonresidential site, a commercial building permit is required. A clearing, grading, and erosion-control permit may be required if the area of ground disturbance is large enough (LCREP 2006). Permitting requirements may depend on the design of the facility. This program protects groundwater resources from injection of pollutants directly underground. The following guidelines are for designers who are considering a stormwater planter to treat runoff before discharging it to surface water. These suggestions will help avoid triggering UIC requirements in the design of a stormwater planter. If a stormwater planter is being considered for pretreating runoff before discharging it to a UIC, the designer should contact ODEQ’s UIC program during early planning stages, as this is considered part of the UIC system and must be authorized as an assembly. However, changes to the design that would allow runoff to shortcut infiltration through the top of the facility could turn the facility into a UIC. Also, when sizing an infiltration planter, avoid designing a facility that is deeper than the widest surface dimension. It would not be a UIC if excess runoff is routed to a stormwater conveyance system that discharges to surface water. Finally, conveying runoff to the surface of an infiltration planter and routing the excess runoff to surface water will help you avoid triggering state UIC requirements. Instead, it filters runoff through mulch and amended soil mix. This filtered runoff is then routed via a nonperforated overflow pipe and ultimately to a stormwater conveyance system discharging to surface water. For more information on low-impact development and UICs, see the ODEQ fact sheet “Identifying an Underground Injection Control” (ODEQ 2015). Metropolitan Council Environmental Services, St. Paul, MN. Accessed from Ellicott City, MD. Asphalt Pavement Association of Oregon. Prepared by City of Portland: Bureau of Environmental Services. Accessed from (WS 0603) Beltsville, MD. Accessed from Prepared by Center for Watershed Protection, Ellicott City, MD. Detroit, MI. Prepared by C. Hinman for Pierce County Extension, Tacoma, WA. Accessed from Accessed from Eastern Washington Low Impact Development Guidance Manual. Pub no. 13-10-036. Slowing the flow of stormwater reduces erosion and flooding dangers.