|
|
Conservation and Natural Environment
Organization of this Chapter
This Conservation and Natural Environment Chapter is divided into the following sections:
The Introduction describes the intent of the Conservation and Natural Environment Chapter and its relationship to Redmond’s vision of the future and other Comprehensive Plan chapters.
The Planning Context describes how the policies in this chapter respond to the requirements of the Growth Management Act and the Countywide Planning Policies.
The Conservation and Natural Environment Policies are divided into the following areas:
A. Environmental Stewardship Policies address the need to consider the long-range implications of City policies upon the environment, to conduct City operations in a manner that protects the environment and to provide for education on how the City, its businesses and residents can improve the quality of the environment.
B. Environmentally Sensitive Areas Policies provide for the protection of areas that contain valuable resources, such as streams, wetlands, wildlife habitats and aquifer recharge areas, and for the proper management of development in areas which represent threats to life or property, such as landslide hazard areas, seismic hazard areas and erosion hazard areas.
C. Water Policies provide for the protection and sustainable use of surface and ground water resources.
D. Wildlife Habitat Policies address the need to protect important wildlife habitats and to connect habitats both within the City and the region to maintain fish and wildlife populations.
E. Tree Preservation and Enhancement Policies address the value of protecting and enhancing trees within Redmond.
F. Air Quality Policies address the need to maintain the quality of the City and region’s air resources.
G. Noise Policies address the protection of the community from the adverse impacts of excessive noise.
H. Views Policies address the protection of public views.
I. Light Pollution Policies address the protection of the community from excessive glare.
(Ord. 1847)
Introduction
edmond residents and businesses have identified Redmond’s natural environment as one of the aspects of the City they value the most. The Conservation and Natural Environment Chapter is intended to protect and enhance the environment within the City of Redmond and the region. The growth of cities modifies the natural environment profoundly; however, the policies in this chapter will maintain key natural processes and protect and enhance important natural features and habitats.
The Conservation and Natural Environment Chapter will implement the vision for Redmond by maintaining the quality of the environment. The vision recognizes the value of lakes, rivers and wetlands. The policies in the chapter will protect these areas and the fish and wildlife which rely on them. The vision recognizes the value of trees and open spaces and this chapter helps to protect them. The vision also calls for timely decision making and ensuring that some economic use will be allowed for all properties. The policies in this chapter are intended to increase predictability, provide for timely decisions and allow for economic use of all properties. These provisions will reduce public and private costs. Retaining the important values and functions provided by the natural environment, such as the flood control functions of natural drainage ways, also will reduce public and private costs.
This chapter also will enhance the quality of life. Protecting the natural environment will provide for features that make for a high quality of life. These include access to attractive natural areas and the recreational opportunities made possible by fish, wildlife and clean water.
The Conservation and Natural Environment Chapter also works with the Land Use and Annexation Chapters to protect important natural features. The Land Use Chapter helps to protect sensitive areas by directing development away from these areas. The Annexation Chapter also excludes large areas of sensitive areas from Redmond’s Potential Annexation Area so that pressures for development of these areas will be reduced.
The Conservation and Natural Environment Chapter also works with other chapters, such as Economic Development and Housing, by keeping the community attractive to businesses and residents by retaining a high quality of life and an attractive city.
(Ord. 1847)
Planning Context
he Comprehensive Plan includes a Conservation and Natural Environment Chapter because Redmond residents and businesses value a high quality natural environment. While the Growth Management Act (GMA) provides that a conservation chapter is optional, the GMA includes as a planning goal the “protect[ion of] the environment and enhance[ment of] the state’s high quality of life, including air and water quality, and the availability of water.” In addition, the GMA requires local governments to protect sensitive areas, also known as critical areas. Sensitive areas include wetlands, critical aquifer recharge areas, fish and wildlife habitat areas, frequently flooded areas and geologically hazardous areas.
The Countywide Planning Policies call for the protection and enhancement of natural ecosystems. The policies also provide for the protection of wetlands, aquifers, fish and wildlife habitats, and air and water quality. They also provide for the regulation of floodplains and geological hazards to lessen damage to public and private property.
This chapter includes policies to protect these resources and manage development in hazardous areas while recognizing that urban development will affect the environment. The policies seek to minimize these impacts by preserving key environmental features and protecting other resources.
(Ord. 1847)
Conservation and Natural Environment Policies
A. Environmental Stewardship
ities, as general purpose local governments, have overall responsibility for the well-being of their communities. Cities must consider the totality of the circumstances affecting the community. For example, cities are responsible for providing public facilities and services, encouraging development in appropriate areas and discouraging development in inappropriate areas. Local governments also are close to the people they serve. This gives the City of Redmond a key role to play as the principal environmental steward for the area within the City. This is a multi-faceted role. The City is responsible for carrying out certain state and federal regulations within the community. These regulations require that Redmond undertake certain activities and manage its operations to protect the environment. The City is also a regulator and, under Washington state law, must consider the environmental effects of those regulations. The City is also an educator. Redmond conducts educational programs to protect the environment, such as its award-winning recycling education program. The City also can teach by example, such as by showing through its operations how to cost-effectively protect the environment. The following policies bring together the City’s activities described above and outline the City’s role as the principal environmental steward.
NE-1 Redmond shall consider the immediate, long range and cumulative environmental impacts of policy, regulatory and service decisions. These impacts shall be considered in the context of the City’s commitment to provide for the public safety, public facilities and services, a high quality of life and economic development in a sustainable environment.
NE-2 Redmond shall conduct City operations in a manner that provides quality municipal services to the community while encouraging resource conservation and minimizing adverse environmental impacts.
NE-3 Redmond should minimize and, where practicable, eliminate the release of substances into the air, water, soil and ground water that may degrade the quality of these resources or contribute to global atmospheric changes.
NE-4 Redmond should encourage the judicious use of renewable natural resources and conserve nonrenewable resources.
NE-5 Redmond should reduce waste, reuse and recycle materials and dispose of all wastes in a safe and responsible manner.
NE-6 Redmond should promote and lead education and involvement programs to raise public awareness of environmental issues, encourage respect for the environment and show how individual actions and the cumulative effects of a community’s actions can have significant effects on the environment.
Environmental issues often extend beyond governmental boundaries. Cooperation between governments is essential to address many environmental problems. Redmond should continue its policy of working cooperatively with others to address environmental issues.
NE-7 Redmond should cooperate with other local governments, state, federal and international agencies and nonprofit organizations to protect and enhance the environment, especially for issues that affect areas beyond Redmond’s boundaries.
Redmond is committed to being a sustainable community. Sustainable development implies that the use of energy and materials in a city and region will be in balance with the energy and materials that can be supplied by the region through renewable means. Renewable means include recycling; reusing; and using materials that can be replaced, such as ethanol from crops. A sustainable community tries to maintain important natural processes, such as groundwater recharge. A sustainable community is not necessarily self-sufficient, but it does try to balance local and regional carrying capacity with international trade. Regional and international economic specialization will continue to occur in Redmond. A sustainable Redmond and a sustainable Puget Sound region can continue to sell medical equipment and software to the world, along with other export goods and services, and buy goods and services from others as long as it maintains important ecological functions, uses renewable resources, and recycles non-renewable resources. The concept of sustainable communities is not yet fully defined; however, Redmond supports its basic concepts and participates in its continuing development.
NE-8 Redmond should strongly support sustainable development and one of the community’s overriding policies is to become a sustainable community.
B. Environmentally Sensitive Areas
nvironmentally sensitive areas are important contributors to Redmond’s high quality of life. Also known as critical areas, environmentally sensitive areas direct development away from hazardous building sites; reduce negative development impacts by providing flood storage, buffers, and natural vegetation to blend with buildings and the surroundings and provide amenities and recreational opportunities for those living and working in nearby developments. The wildlife that inhabit some of these areas also provide an important amenity to those who live and work nearby.
(NOTE: All of the Sensitive Areas Maps referred to in this chapter are available upon request from the Comprehensive Planning Division of the City of Redmond Planning Department.)
Overall Sensitive Areas Policies
Redmond manages nine different types of sensitive areas: four geologic hazards, frequently flooded areas, wetlands, streams, aquifer recharge areas and wildlife habitats. Wildlife habitats are discussed separately in Section D.
The policies in this chapter include the term “characterized by urban development.” Areas characterized by urban development include areas planned or developed for residential uses with an average gross density of more than one unit per acre, commercial uses, office uses, manufacturing uses and similar uses of an urban nature or intensity.
As will be described below, sensitive areas are hazardous to develop. They also perform important natural functions. The following policies set out Redmond’s general policies towards sensitive areas. These policies are amplified in the following sections of this chapter.
NE-9 Hazardous areas and significant areas of steep slopes, undeveloped shorelines and wetlands shall be kept as open space.
NE-10 Environmentally sensitive areas should be conserved and protected from loss or degradation. In areas planned for substantial urban development, sensitive areas may be modified where they have low ecological value and the function and values will be fully replaced or where the impact on the resource may be reduced to acceptable levels. Land uses and developments that are incompatible with environmentally sensitive areas shall be restricted within those areas.
One of the best opportunities to protect sensitive areas while allowing an appropriate level of development is during the subdivision process. Before lots are created and streets laid out, it is possible to design the subdivision so that development is allowed in appropriate areas while preventing development in hazardous areas or important habitats. The following policy is intended to guide the subdivision of lands that include sensitive areas.
NE-11 Outside of areas already characterized by urban development, new lots shall not be created unless the lot has a building site outside any one of the following areas:
(a) 100-year floodplains;
(b) Class III and Class IV landslide hazards;
(c) Wetlands that would not be developed under the Sensitive Areas Regulations;
(d) Soils unsuited to development;
(e) Streams;
(f) Critical wildlife habitats; and
(g) Buffers required by sensitive areas regulations.
Within areas characterized by urban development, the creation of lots with buildings sites entirely within these areas should be avoided where possible.
Another way of protecting sensitive areas while providing for appropriate levels of development is to focus development on the areas of the site best suited to development while leaving sensitive areas undeveloped. This is referred to as clustering or density transfers. Clustering can be accomplished through the Planned Unit Development process, the subdivision process, the binding site plan process and through other means.
NE-12 Planned Unit Developments (PUDs), clustering and density transfers should be encouraged for both commercial and residential development to help retain significant natural features and sensitive areas as open space.
While protection of sensitive areas is important to the Redmond community, allowing all properties some reasonable economic use also is important. This view is so important it is included in the framework policies within the Vision Chapter. These policies do not guarantee that each property will be able to be used for its theoretically highest and best use or that all of a property can be used. Rather, the policies provide that the sensitive areas regulations should be administered so that each property taken as whole should have some economic use.
NE-13 The sensitive area regulations should provide some economic use of all property within Redmond, taking into account the entire property.
Consistency between jurisdictions can help citizens and the development community work more efficiently with sensitive areas regulations. Consistent sensitive areas regulations also can reduce training and implementation costs for local governments. While local variations need to be accommodated, the local governments in King County are committed to making sensitive areas regulations more consistent.
NE-14 Redmond shall work cooperatively with other jurisdictions in King County to develop and implement sensitive area regulations, designations and education programs that meet the goals of the Redmond community and provide for optimal consistency among jurisdictions.
Geologic Hazards
There are four types of geologic hazards: areas with a significant risk of landslides, areas subject to high erosion potential, areas where their geological structure make them susceptible to earthquake damage and areas that have soils that are unsuited to development.
Landslide Hazard Areas. Landslides are a significant problem in the Puget Sound region. Factors such as the slope, soils, geology and ground water conditions determine the landslide hazard. Areas subject to landslides are hazardous to people building on them and the community as a whole. In a landslide, buildings and improvements within landslide hazard areas are likely to be damaged or destroyed. If occupied, those present may be injured. Building on landslide hazard areas may increase the likelihood that a slide will occur. Removing the natural vegetation that helps stabilize a slope increases the risk of slides. The construction of buildings and access ways can cut slopes, increasing the likelihood of a slide. Increasing impervious surfaces on slopes increases runoff which, if it stays on the surface, can cause erosion that makes slopes unstable. If the water enters the soil, it may increase the potential for slides by making the soil heavier and lubricating the soil layers and particles. This reduces the friction that helps keep the soil and rock in place. Landscape watering can also have these destabilizing effects.
These increased hazards can affect areas outside landslide hazard areas as well. Earth and mud can flow onto nearby properties. A slide on a high hazard area may destabilize areas of less severe hazards. The material from a slide and the exposed area is subject to erosion, with a high potential to pollute nearby rivers, lakes and streams. For all of these reasons, Redmond has adopted policies and regulations to appropriately manage these hazardous areas.
The map entitled “Landslide Hazard Areas” shows the general locations of Classes I (Low Hazard) through IV (Very High Hazard) landslide hazard areas. These areas were identified and mapped based on examination of US Geological Survey (USGS) geologic maps and topographic maps and on limited field checking. In identifying sites subject to landslide hazards, the definitions below and actual conditions define the hazard areas and shall take precedence over the maps.
Landslide hazard areas are classified based on the degree of risk as follows:
▀ Class I/Low Hazard: Areas with slopes of less than 15%.
▀ Class II/Moderate Hazard: Areas with slopes of between 15% and 40% and that are underlain by soils that consist largely of sand, gravel or glacial till.
▀ Class III/High Hazard: Areas with slopes between 15% and 40% that are underlain by soils consisting largely of silt and clay.
▀ Class IV/Very High Hazard: Class IV areas include the following:
(a) Areas with slopes steeper than 15% with mappable zones of emergent water (e.g., springs or ground water seepage);
(b) Areas of known (mappable) landslide deposits regardless of slope, and
(c) All areas sloping more steeply than 40%.
NE-15 To avoid and minimize potential impacts to life and property from geologic hazards, Redmond shall require appropriate levels of study and analysis for construction within Class II through IV landslide hazard areas, ensure that sound engineering principles are used in these areas and use regulations to appropriately limit land uses in areas of high hazards. Transfers of densities from Class II through IV areas shall be strongly encouraged. For properties designated Large Lot Residential, a fifty percent density bonus shall be given if the housing units allowed on geologic hazards are transferred to other areas.
NE-16 Buildings shall be prohibited in Class IV landslide hazard areas, subject to the provisions of Policy NE-13. Class IV landslide areas shall be avoided where possible, and the intrusion into Class IV landslide areas minimized and properly stabilized.
Erosion Hazard Areas. Erosion is a natural process whereby wind, rain, water and other natural agents mobilize and transport soil particles. Lands are susceptible to varying degrees of risk of erosion based on a combination of slope, soil characteristics and exposure to wind or water.
Because it is a natural process, the Northwest environment is adapted to a certain level of erosion. Unfortunately, development, particularly in areas susceptible to erosion, can overwhelm the environment’s capacity to accommodate sediment. This can result in clogging of streams and drainage facilities, flooding nearby properties during storms. Sediment is also a pollutant which can smother the eggs in salmon spawning beds or cement up the beds and thus prevent spawning. Sediment can reduce the sunlight available to aquatic plants, thereby decreasing their productivity. Sediment also can smother aquatic plants and immobile aquatic animals, such as freshwater mussels. Eroded soil also can liberate minerals, increasing algal growth to levels that reduce water clarity and available oxygen in the water. The algal growth and sediment also discolor clear waters, making them less desirable for recreational use. For all of these reasons, Redmond has adopted policies and regulations to appropriately manage these hazards.
The map entitled “Critical Erosion Hazard Areas” used US Department of Agriculture Soil Conservation Service (SCS) Soil Survey data to identify lands having a high or very high risk of erosion. These lands typically slope 15% or greater and are characterized by the following types of soils: Alderwood-Kitsap (AkF), Alderwood gravelly sandy loam (AgD), Kitsap silt loam (KpD), Everett (EvD) and Indianola (InD). In identifying sites subject to erosion hazards, the definitions and actual conditions define the hazard areas and shall take precedence over the maps. Citywide clearing and grading requirements, which help reduce erosion also are called for in Policy NE-38.
NE-17 Uses that require substantial improvements or structures shall be directed away from critical erosion hazard areas.
NE-18 Development in erosion hazard areas should be managed to minimize erosion during both construction and use.
Seismic Hazard Areas. Since 1840, there have been at least 222 earthquakes strong enough to be felt in the Puget Sound region. Six were strong enough to damage poorly built structures. Because of its geologic structure and history of earthquake activity, the region has been designated as a Class III seismic risk zone, the highest rating given by the United States Geologic Survey.
Earthquakes can damage structures that are not built to withstand those forces, wherever their location. Because of soils and geology, certain areas are also more susceptible to earthquake damage than others. Buildings in these areas are at a high risk of damage, potentially injuring persons and property both inside and outside the building. Earthquakes also can damage public facilities such as roads, water lines, sewer lines, electrical lines and gas lines. For these reasons, development in areas more susceptible to earthquake damage has high potential public and private costs.
Like other sensitive areas, the hazards created by developments in seismic hazard areas extend beyond the properties within the area. One of the greatest hazards from earthquakes is fire. Although modern appliances, construction techniques and fire fighting equipment and methods have reduced the damage from fires, recent earthquakes show that the risk of fire and explosion is still significant. Fires result from broken gas lines, broken containers holding flammable materials and downed or shorted electrical lines. Fires caused by earthquakes are all the more dangerous because the community’s main weapon for fighting fires, its water system, may be damaged by an earthquake, reducing the amount of water available and the water pressure. For all of these reasons, Redmond has adopted policies and regulations to appropriately manage these hazardous areas.
The map entitled “Seismic Hazard Areas” identifies lands that, due to a combination of soil and ground water conditions, are subject to severe risk of ground shaking, subsidence or liquefaction of soils during earthquakes. These areas are typically underlain by soft or loose saturated soils (such as alluvium), have a shallow ground water table and typically are located on the floors of river valleys. The map is based on US Department of Agriculture Soil Conservation Service soils maps. In identifying sites subject to seismic hazards, the definitions and actual conditions define the hazard areas and shall take precedence over the maps.
NE-19 Uses that require substantial improvements or structures shall be directed away from seismic hazard areas not already characterized by urban development.
NE-20 Development in seismic hazard areas should be constructed, maintained and operated to minimize hazards to persons and property within the seismic hazard area and the entire community.
Soils Poorly Suited to Development. Some soils, such as those that consist of peat or have a high proportion of very fine materials, are poorly suited for development. Peat is an organic deposit made up of partially decomposed plants. Peat soils cannot support heavy loads, such as roads or building foundations. Fine materials include silts and other materials. These soils also have difficulty supporting weight. Peat soils are found in floodplain areas previously occupied by wetlands. Soils with a high proportion of fine materials can be found on certain ridges in the Redmond area.
NE-21 Uses that require substantial improvements or structures shall be directed away from areas with significant amounts of soils unsuited to development and not already characterized by urban development.
NE-22 Development on soils unsuited to development should be constructed, maintained and operated to minimize hazards to persons and property within the area and the entire community. In reviewing development in these areas, Redmond may require studies necessary to show that the hazards presented by the soils are adequately mitigated.
Soils unsuited to development have not been mapped, although peat soils are identified in the soil survey for King County. Redmond should undertake a study to map soils unsuited to development and properly manage development in these areas.
NE-23 Redmond should map significant areas of soils unsuited to development. These soils should be managed through discretionary development reviews.
Frequently Flooded Areas
Like seismic hazard areas, frequently flooded areas are a hazard to both people and property within defined areas and the community as a whole. Frequently flooded areas are generally categorized into three classifications: the floodplain, the zero-rise floodway and the one-foot-rise floodway.
The floodplain is the area that is likely to be covered with water during a given frequency of flooding. The Federal Emergency Management Agency and Washington State law require local governments to manage the 100-year floodplain. The 100-year floodplain is the area with a 1% chance of being flooded in any given year.
The floodway is that part of the floodplain reserved to convey flood waters. Redmond regulates two floodways: the zero-rise floodway and the one-foot-rise floodway. The zero-rise floodway is the area that must be reserved to prevent any increase in flood heights, assuming the remainder of the floodplain would be fully developed. The one-foot-rise floodway is the area that must be reserved to prevent an increase greater than one foot in flood heights, again assuming the remainder of the floodplain would be fully developed.
The map entitled “Floodplains” identifies lands determined by a Federal Emergency Management Agency’s (FEMA) Flood Insurance Study to be within the 100-year floodplain. It is important to recognize, for reasons described below, that properties outside the identified 100-year floodplain may be subject to flood damages.
Flooding can damage buildings within the floodplain. Persons living or working within the floodplain are at risk of injury from floods and from the diseases that can be spread by flood waters. Floods can damage public facilities, increasing the public costs of development.
Construction within a floodplain also may harm neighboring properties. Buildings and embankments can backup water behind them, flooding neighboring properties. If flood waters destroy a building or wash away materials stored on site, these materials can strike against buildings or bridges and damage them. For all of these reasons, Redmond has adopted policies and regulations to appropriately manage these hazardous areas.
NE-24 Redmond shall regulate development in the 100-year floodplain to avoid substantial risk and damage to public and private property and loss of life. These regulations shall, as a minimum, comply with state and federal requirements for floodplain regulations.
NE-25 Uses that require substantial improvements or structures shall be directed away from areas within the 100-year floodplain and not already characterized by urban development.
NE-26 Public facilities should not be located within the 100-year floodplain unless needed to serve development within areas characterized by urban development or because efficiencies from locating near existing public facilities already within the 100-year floodplain would clearly outweigh the risk of damage to the facility.
NE-27 Development in the 100-year floodplain should be constructed, maintained and operated to minimize hazards to persons and property within the 100-year floodplain and the entire community.
NE-28 Redmond should update its policies and development regulations to incorporate better data on the extent of flood hazards as it becomes available.
NE-29 Redmond should cooperate with flood hazard reduction planning carried out by King County and update its policies and development regulations to incorporate appropriate recommendations from these studies.
Redmond does not apply the zero-rise floodway to that portion of Bear Creek which is downstream of Redmond Way and upstream of the confluence of Bear Creek and the Sammamish River. While King County identified some of the zero-rise floodway within Redmond as part of the Bear Creek Basin Plan, this data is not available for the entire City. Priority should be given to studies that will identify the zero-rise floodway to more efficiently carry out this policy.
NE-30 Redmond shall enforce a zero-rise floodway along lakes and Class I streams when the zero-rise floodway has been identified. The zero-rise floodway shall not apply to those areas which previously have been excluded. Redmond should give priority to conducting studies that identify the extent of the zero-rise floodway.
As development occurs within a basin, the 100-year floodplain will expand, exposing some properties that were previously outside the floodplain to potential flood damage. Properties already within the floodplain will become subject to deeper and faster flowing flood waters. These effects occur because as a basin develops the amount of impervious surfaces increase, increasing runoff and therefore flood depths. While the stormwater management policies in this chapter will reduce these effects, they cannot prevent them entirely. Consequently, it is important that Redmond and persons building or undertaking uses in areas near floodplains take these changes into account. One way of anticipating and responding to these changes is to identify the future-conditions floodplain. The future-conditions floodplain is the area that will be inundated by a 100-year flood when the basin is fully developed. FEMA flood hazard maps are based on current and historic conditions, not buildout. So additional work is needed to identify the future-conditions floodplain.
NE-31 When data on the future conditions floodplain becomes available, Redmond should incorporate this data into flood control and regulatory activities.
NE-32 Reductions in the FEMA floodway should only be allowed if future flows have been considered and adequately accommodated.
Natural drainage courses both within and outside the 100-year floodplain can help lessen flood damages. Properly functioning natural streams and drainage ways include pools and overflow areas that slow stormwater runoff. Retaining natural drainage courses also helps to accommodate stormwater flows from upstream properties. When streams are placed within culverts or pipes, waterways are not able to convey flows as large as those conveyed by open channel streams. Placing streams within pipes or culverts also reduces their value as fish, wildlife and plant habitat. The culverts and pipes also create barriers to fish migration. While some stream crossings are inevitable, they should be kept to a minimum and should use crossing methods that have as little impact on the stream’s capacity to convey water and the natural environment as possible. Those streams that have been enclosed in culverts should be reopened where reestablishing the streams would result in significant benefits. If the City accepts an alteration where a developer may gain greater usability of the site by altering the stream location, enhancement of the existing stream is required.
NE-33 Alteration of streams should be avoided. The capacity of natural drainage courses should not be reduced. Enclosing natural drainage ways should be minimized. Relocation should be discouraged. Where relocation or alteration is necessary, the flood control and habitat values of the drainage course shall be fully replaced and enhancement shall be encouraged. In the case where the City accepts alteration of a stream to increase the usability of a site, enhancement shall be required.
NE-34 The preferred method of crossing a water course that has habitat suitable for fish use or may be rehabilitated for fish use in the future is a bridge. The use of culverts shall be prohibited where a fish barrier would result. Culvert systems that would provide stream beds similar to natural channels may be allowed where loss of habitat would not be significant and the cost of a bridge does not justify its benefits to fish passage, flood control or other resources.
NE-35 Natural drainage channels that have been placed within culverts and have had their capacity or habitat value reduced should be restored where feasible as development or redevelopment occurs. Existing culverts may be retained for stream crossings where they do not result in a fish barrier in a stream that contains or has the potential to contain fisheries habitat.
Properties outside the 100-year floodplain also can aggravate flooding and flood damages. As discussed above, development in landslide or erosion prone areas can lead to the clogging of streams and drainage systems, increasing flooding within and outside the 100-year floodplain. As areas outside the 100-year floodplain develop, increased impervious surfaces may increase runoff during storms and thus increase flood heights within the 100-year floodplain and cause flooding outside the existing 100-year floodplain. Increased stormwater runoff also can reduce salmon and steelhead habitat by literally washing it away. Reducing the amount of impervious surfaces and stormwater detention can help reduce these impacts. Reducing impervious surfaces can be achieved through development regulations.
NE-36 Impervious surfaces should be minimized outside the Urban Center to reduce the possibility of flooding, to protect the environment and to allow for ground water recharge.
NE-37 Redmond shall adopt limits on the amount of impervious surfaces allowed within each of the zoning districts. These standards should protect environmental resources such as streams and allow for ground water recharge, allow for efficient land use, and accommodate the level of development intensity planned for the area.
Stormwater detention and treatment requirements are included in the Stormwater Management Manual for the Puget Sound Basin. This manual contains uniform requirements that all local governments should consider to reduce stormwater runoff. A regional approach is most appropriate for stormwater because it is most effectively managed on a basin level. Activities upstream from Redmond can result in flooding in Redmond. Activities in Redmond can cause flooding downstream in Woodinville and Bothell. If all the jurisdictions in the basin adopt uniform and effective regulations, both the costs and benefits of the solution will accrue to everyone. Adopting generally consistent stormwater management standards that still provide for appropriate local variations also will make administration of those regulations more efficient for both applicants and local governments, promoting regulatory reform. Stormwater policies related to the manual are in the Utilities Chapter.
Clearing and grading for developments also can increase stormwater runoff by removing vegetation and organic soils that absorb rain water. Excessive clearing and grading can lead to erosion that pollutes rivers, creeks and lakes. To prevent these negative impacts, Redmond should continue to adopt and enforce clearing and grading requirements to minimize runoff and erosion.
NE-38 Clearing and grading regulations shall be adopted and implemented to minimize the overall impact of the activity on the environment. Generally, clearing should be limited to the parts of site that will be developed.
River basin planning is another basin-based approach to floodplain management. River basin plans can address both floodplain and water quality issues. Policies related to basin planning are contained in the Surface Water policies below.
State law requires that to be eligible for state Flood Control Assistance Account Program (FCAAP) grants, the county must prepare and adopt a comprehensive flood hazard reduction plan. Local government flood control projects must be consistent with this plan to be eligible for FCAAP funding. City policies also must be consistent with the comprehensive flood hazard reduction plan. King County has prepared and adopted the King County Flood Hazard Reduction Plan to comply with this requirement. In addition to the reasons described above, the policies in this section also are intended to comply with the Flood Hazard Reduction Plan. Redmond should work cooperatively with King County to implement this plan in the Sammamish River basin.
NE-39 Redmond should support and help implement the relevant policies of the King County Flood Hazard Reduction Plan.
Wetlands
Flood control is one of the many important functions that wetlands perform. Wetlands can store water that would otherwise flow downstream and flood properties. Other wetlands functions include maintaining water quality by filtering out sediments and other pollutants, providing important fish and wildlife habitat, protecting uplands from erosion due to wind and waves, providing for passive recreation, providing nutrients that feed organisms living in streams and rivers and providing opportunities for research and scientific study. Some wetlands may contribute to ground water recharge by capturing rain water and allowing it to seep into the ground. Wetlands are one of the key natural processes that the Conservation and Natural Environment Chapter seeks to retain and restore.
Wetlands filling and draining interferes with all of these important functions. The loss of these functions can have a significant negative impact on individual land owners and on the community as a whole. For example, some of Redmond’s Downtown and research and development and manufacturing parks are located within the floodplain. The loss of wetlands that store flood waters may damage downstream property owners and public facilities. Some of these negative impacts can be mitigated, others are difficult or impossible to mitigate.
Wetlands also can also be hazardous areas to develop. Wetlands soils generally are poorly suited for development as they often are high in organic materials and may not support foundations, streets or utilities. Wetlands may be subject to flooding. For all of these reasons, Redmond has adopted policies and regulations to appropriately manage these hazardous areas.
The map entitled “Wetlands” identifies areas determined likely to contain wetlands based on a “reconnaissance-level” inventory. This inventory was based on aerial photographs, National Wetlands Inventory maps, soil data and other information. Areas shown on this map as containing wetlands may not include such areas. Similarly, areas not shown as containing wetlands may include them. The exact wetlands status of a property can be determined only by a field study conducted by a qualified wetlands biologist. In identifying wetlands areas, the definitions and actual conditions define the hazard areas and shall take precedence over the maps.
NE-40 Wetlands should be preserved. The size and value of the wetlands shall determine the amount of development allowed, if any.
NE-41 On a city-wide, long-term basis, Redmond shall achieve no net loss of wetlands function and value. Redmond should seek to maintain wetlands acreage over the long-term.
NE-42 In undertaking public projects and deciding development applications, Redmond shall first seek to avoid wetlands impacts. Where impacts cannot be avoided, the impacts shall be minimized and any adverse impact mitigated. On-site, in-kind mitigation generally is preferred. Other forms of mitigation may be allowed where consistent with these policies and Redmond’s sensitive areas regulations.
NE-43 The amount of mitigation required should reflect the value of the wetlands affected by the project, the risk that the mitigation may fail, the temporal loss of wetlands functions and values, the spatial locations of the mitigation and the difficulty of replacing many wetlands functions and values. For these reasons, a significantly larger area of mitigation should generally be required than the area of wetlands impacted.
NE-44 Degraded wetlands should be enhanced and restored where possible.
Streams
Streams are another important aquatic sensitive area. Both intermittent and year-round streams provide fish and wildlife habitat, convey stormwater and provide for other important values, including open space and recreation. Interference with these valuable functions can lead to loss of fish and wildlife, flooding of nearby properties, damage to public facilities from flooding and erosion and other negative impacts. Streams are one of the key natural processes that the Conservation and Natural Environment Chapter seeks to retain and enhance.
The map entitled “Streams” shows the streams and waterways identified, based on aerial photographs, county and state inventories, field reconnaissance and local knowledge. Like wetlands, there may be other streams that are not on this map. In identifying streams, the definitions and actual conditions define the hazard areas and shall take precedence over the maps.
The policies related to streams can be found in the Frequently Flooded Areas policies in Section B and Section C, Surface Water.
Ground Water and Aquifer Recharge Areas
Redmond obtains water from two sources: Redmond purchases water from the City of Seattle and Redmond also has its own wells that supply water for domestic, commercial and manufacturing uses.
Aquifer recharge areas are one of the key natural processes that the Conservation and Natural Resources Chapter seeks to retain. Redmond’s current municipal supply of ground water is found at shallow depths in a water table aquifer. An aquifer is a sizable and continuous body of porous material composed of sand, gravel or silt saturated with water and capable of producing usable quantities of water to a well. As required by federal law, this water is monitored and tested to insure that it meets the high standards required for drinking water. The City’s wells pump high quality ground water. This high quality could be attributed to past land use practices in the municipal aquifer recharge area.
Water Quality. The City’s municipal water supply aquifer faces two principal threats. The first is contamination from polluted surface water, polluted ground water or hazardous material spills. Redmond should manage areas which present a significant risk of contamination to protect the high quality of the ground water resources. Measures that can protect ground water quality include ground water monitoring, constructing buildings and work areas to contain spills, prohibiting dry wells in commercial and manufacturing areas, minimizing the use of materials that may contaminate ground water, such as herbicides used for right-of-way maintenance, and directing uses that pose a high risk of contamination away from locations where contamination would be more likely. Education of both the public and businesses can play a major role in protecting ground water quality. Education is addressed in Policy NE-64. Other ground water quality protection policies are included in the Utilities Chapter.
NE-45 Redmond and other jurisdictions shall protect the quality of ground water used for public water supplies to insure adequate sources of potable water for Redmond and the region. The level of protection provided shall correspond with the potential for contaminating the municipal water supply aquifer. The overall goal should be nondegradation of ground water quality. Waste water and potentially contaminated stormwater should not be discharged to ground water.
NE-46 Redmond should adopt and implement an aggressive program to protect the municipal water supply aquifer.
Water Quantity. The second threat facing the City’s municipal water supply aquifer is reduced ground water recharge. For water to be pumped on a sustainable basis, new water must enter the aquifer. The best available data indicates the aquifer is recharged by rain water infiltrating into the ground through permeable soils and by recharge from rivers, streams and lakes. Wetlands and natural area-wide landscape depressions that allow water to stand also may aid in ground water infiltration by slowing runoff and allowing it to seep into the ground when located in suitable areas. Development can lessen the water entering the aquifer by covering recharge areas with impervious surfaces or filling wetlands and natural depressions that contain standing water. Important ground water recharge areas that are planned for rural or natural resource uses should be retained in these uses. These areas include the northern Sammamish Valley and the Bear Creek and Evans Creek valleys.
NE-47 Redmond and other jurisdictions shall retain aquifer recharge capacity in areas that have not already been committed to urban uses.
In urbanized areas, maintaining open space, areas of natural vegetation and wetlands also can help recharge aquifers. Many developments include some open spaces or recreation areas. By siting these areas on lands with the highest potential for ground water recharge they can do double duty, providing both aesthetic and recreational functions and ground water recharge. These areas must be carefully located to minimize the potential for contaminated water to enter the aquifer. The amount of land used for open space in a development should vary with the type of development and its location. Within the Urban Center, very little land will be reserved for these purposes.
NE-48 Open spaces, tree protection areas and other areas of protected native vegetation should be encouraged in those areas with a high potential for ground water recharge and which can be protected from contaminated stormwater runoff.
Minimizing impervious surfaces also can help to maintain ground water recharge. This method also has the advantage of reducing stormwater runoff. Policy NE-37 calls for limits on impervious surfaces. Recommendations in other chapters also help minimize impervious surfaces. Both the Transportation and Housing Chapters recommend reductions in street widths. This has the potential to significantly reduce stormwater runoff and increase ground water infiltration.
Hazardous material cleanups also have the potential to protect and improve ground and surface water quality. State and federal programs require that certain properties contaminated with hazardous materials be cleaned up. In addition, many property owners voluntarily cleanup contaminated land. Redmond does not have many contaminated sites, but the City should encourage cleanups. Redmond also should work with property owners and state and federal agencies to ensure that sites that may affect ground water supplies are cleaned up thoroughly so they do not present a future threat to ground water quality.
NE-49 Redmond should encourage hazardous waste cleanups within the City. To encourage such cleanups, Redmond should ensure that its regulations and standards are flexible, do not duplicate state and federal requirements and provide for expeditious approval were local review is required.
NE-50 Contaminated sites that may affect Redmond’s ground water supplies shall be cleaned to such a standard that the sites will not present a risk to drinking water supplies.
C. Surface Water
edmond’s waters contribute strongly to Redmond’s quality of life. Redmond residents enjoy swimming and boating on Lake Sammamish, canoeing on the Sammamish River and fishing and wildlife viewing along Redmond’s lakes, river and streams. All of these activities depend on high water quality. Developed areas can adversely effect water quality by generating stormwater runoff containing potential contaminants.
NE-51 Salmon, steelhead and other fish, plants and wildlife that rely on the aquatic environment shall be protected by protecting and improving water quality.
Development in the watersheds of rivers, streams and lakes can adversely affect their water quality. Development can be managed to reduce these impacts. One method of managing development to protect surface water quality is clearing and grading regulations. A clearing and grading policy was included in the frequently flooded areas policies. There are other measures to protect surface water quality as well.
NE-52 Surface water quality should be protected and enhanced. The flow of nutrients (especially phosphorus), heavy metals and other pollutants into streams, rivers, lakes and natural wetlands should be controlled. Treatment measures shall be required where the development results in discharges to surface or ground waters.
The Cities of Redmond, Bellevue, Issaquah and King County prepared the 1996 Lake Sammamish Water Quality Management Plan. The goal of this plan is to keep the water quality of the lake at its 1995 level. The most significant water quality problem in Lake Sammamish is increased phosphorous. The plan includes a comprehensive program to maintain the water quality of the lake.
NE-52A The water quality of Lake Sammamish shall be maintained at its 1995 level. Water quality should be protected by:
▀ Retaining forests in the basin and controlling phosphorus runoff from forest land.
▀ Increasing assistance to residents and businesses to help them use best management practices (BMPs) to reduce the phosphorus flowing into the lake. The use of non-phosphorus organic fertilizers and alternatives to fertilizers should be encouraged as part of this assistance.
▀ Improving government facility maintenance to reduce phosphorus in runoff.
▀ Using an adaptive management approach to monitor water quality and the effectiveness of the plan’s measures.
▀ Exploring opportunities to increase public ownership and access to Lake Sammamish.
▀ Supporting a statewide ban on phosphates in all household and landscape products.
▀ Reducing by 50 percent, on average, the total phosphorus in storm water runoff from new urban development within the Lake Sammamish basin.
The Washington State Department of Ecology has a policy that prohibits the discharge of municipal or industrial waste water into the Lake Washington Basin, including Lake Sammamish and the Sammamish River. Redmond shall support that policy.
NE-53 Municipal and industrial waste water shall not be discharged into the Lake Washington basin.
The Puget Sound Water Quality Plan encourages the preparation of basin plans to address water quality issues for all watersheds that drain to Puget Sound, including the Sammamish River basin in which Redmond is located. The Puget Sound Water Quality Plan refers to these plans as Watershed Action Plans. The plans address stormwater and water quality problems basin-wide. They also can address flooding. Redmond has participated with King County in the development of the Bear Creek Basin Plan, an example of a Watershed Action Plan. Another basin plan has been prepared for the East Sammamish Plateau. King County will prepare a plan for the entire Sammamish basin.
NE-54 Redmond shall cooperate with King County and other local governments and state agencies in developing and implementing Watershed Action Plans and other types of basin plans for basins which include or are up stream from the City of Redmond. Redmond should have substantial participation in the preparation of these plans.
NE-55 Redmond should prepare or participate in the preparation of Watershed Action Plans for all watersheds in the City within 10 years of adoption of this Comprehensive Plan. These plans should address water quality, stormwater runoff and flooding issues. For intensively developed areas, such as Urban and Advanced Technology Centers, these plans should consider the feasibility of regional detention and treatment facilities. Once prepared, the plans should be monitored and amended as appropriate. Each plan should be reviewed at least once each five years.
NE-56 Redmond should incorporate the applicable and reasonable recommendations of Watershed Action Plans (basin plans) into its Comprehensive Plan, Development Regulations and capital facilities plans.
The habitat in Redmond’s rivers, streams and lakes is important to protecting the area’s high quality of life and valuable aquatic resources. Lakes, rivers and streams also contribute to the area’s natural beauty. Lake Sammamish is highly valued for its recreational opportunities, high water quality and views. The Sam-
mamish River, with its trail and parks, is an important focal point for Redmond and ties the City into a regional recreational network. The Sammamish River and area creeks are important to salmon and steelhead migration. The river and area creeks also provide important fish spawning and rearing habitat.
NE-57 Redmond shall protect and enhance natural rivers, streams and lakes, including riparian and shoreline habitat, to protect water quality, reduce public costs, protect fish and wildlife habitat and prevent environmental degradation. The protected features should include natural hydraulic and ecological functions, fish and wildlife habitat, recreational resources and aesthetics.
NE-58 Both year-round and intermittent streams shall be protected.
NE-59 Redmond should include policies in the Shoreline Master Program policies to protect aquatic habitats.
Riparian corridors consist of vegetation along river and stream banks that are influenced by the surface waters. Riparian vegetation is an important source of habitat. Riparian vegetation also contributes to the productivity of rivers and streams by shading these waterbodies, reducing their summer temperature; providing food sources, such as leaves and insects; and, if vegetation is large enough, allowing for fallen logs that give streams structure and help to provide pools and otherwise improve habitat.
NE-60 Development should avoid impacts to riparian corridors. Riparian vegetation should be protected. The enhancement and rehabilitation of these areas shall be required if they are impacted by development and encouraged when development takes place on adjacent uplands.
NE-61 The natural appearance of stream corridors should be preserved and enhanced.
The Sammamish River and some area streams have been channelized and adversely impacted by other forms of development. Channelization refers to relocating a river or stream into a relatively straight, uniform channel. Channelization reduces the habitat values of rivers and streams and increases the speed at which water flows through, potentially increasing downstream flooding. While it is not possible to always return these water bodies to their original condition, restoring rivers and streams can improve fish and wildlife habitat, environmental functions, recreational uses and aesthetics. It also can reduce flood damage. Restoration of these areas should be encouraged.
NE-62 The Sammamish River, Bear Creek and other adversely effected creeks should be restored to the extent feasible, given costs and other constraints.
NE-63 Improvements to the fisheries habitat of watercourses should be encouraged when abutting properties are developed.
Public education is an important component in efforts to protect surface and ground waters. Surface and ground water quality can be adversely affected by individual choices that we make regularly. Education can help people and businesses choose options that meet their needs and desires while protecting surface and ground water quality.
NE-64 Redmond should support public education to protect and improve surface and ground water resources by:
▀ Increasing the public’s awareness of potential impacts on water bodies and water quality.
▀ Encouraging proper use of fertilizers and chemicals on landscaping and gardens.
▀ Encouraging proper disposal of materials.
▀ Educating businesses on surface and ground water protection best management practices in cooperation with other government agencies and other organizations.
▀ Educating the public and businesses on how to substitute materials and practices with a low risk of surface and ground water contamination for materials and practices with a high risk of contamination.
In addition to the policies in this section, policies related to streams and surface waters can be found in the Frequently Flooded Areas policies in Part B. The Utilities Chapter also includes policies encouraging water conservation which can help protect both surface and ground water resources by reducing demand for ground water and reducing runoff from lawns and other areas into surface waters.
D. Wildlife Habitat
edmond residents highly value wildlife. The salmon and steelhead are enduring symbols of the Northwest. Birds are valued for their songs and appearance. Other wildlife is attractive and helps maintain the valued character of the area. Wildlife diversity often is an indicator of environmental health.
Protecting wildlife requires protection of habitat and measures to tie the protected habitats together. The process of urbanization results in the conversion of wildlife habitat to other uses. However, the loss of certain types of habitat can have significant, adverse effects on the health of certain species. These types of habitat are referred to as critical wildlife habitats. Critical wildlife habitats include the habitats of species which state or federal agencies have designated as endangered, threatened, sensitive, candidate or other priority species; heron rookeries; raptor nests, such as eagle nests, and high quality (Class I) wetlands and streams. Redmond protects these habitats.
NE-65 Redmond shall protect critical wildlife habitats within the City.
NE-66 Land use plans and developments should avoid impacts on critical wildlife habitats and restore and enhance degraded or lower quality critical wildlife habitats.
NE-67 Developments, parks and recreation areas should be designed to minimize harassment of fish and wildlife.
As a community develops, the available wildlife habitats become separated from each other. In part, this a natural consequence of the development of urban areas. Unfortunately, this can isolate the plants and animals that live in critical wildlife habitats and lead to interbreeding or the loss of wildlife if the area is too small. If the pieces of critical habitat are tied together, populations can move between the habitat areas. This lessens the dangers of interbreeding and allows plants and animals to recolonize the underused habitats. Habitat fragmentation is addressed by protecting resource lands, such as the Sammamish Valley, and rural areas, such as the Bear Creek Valley; and providing for open space corridors that connect protected habitats and allow wildlife to move through urbanized areas.
NE-68 Habitat fragmentation should be minimized by linking wildlife habitats and discouraging preservation of small, isolated areas. Wildlife habitats should be connected with each other within the City and the region to achieve a continuous countywide network. Links can include park lands usable by wildlife, open space corridors and locating habitat areas adjacent to each other where possible. Riparian areas adjacent to creeks, rivers, lakes and wetlands can serve as important links between wildlife habitats. In circumstances where they are wide enough, trail systems can link wildlife habitats. These trails and the habitat within them must be carefully managed to provide for both habitat and recreational functions without conflicts.
Critical habitats also will be linked through the open space corridors provided for by the Parks and Recreation Chapter.
Many species of fish and wildlife are quite mobile and move from jurisdiction to jurisdiction during their life or with the seasons. This mobility requires a regional approach to their management.
NE-69 Redmond should coordinate land use planning and management of fish and wildlife resources with other local governments within the region, affected state and federal agencies and Indian Nations and Tribes.
E. Preservation and Enhancement of Trees
rees aid in stabilizing the environment’s ecological balance by helping to purify the air, generating oxygen, slowing and absorbing stormwater runoff, stabilizing slopes, reducing erosion, masking noise, containing glare and conserving energy. They enhance the community’s appearance, identity and natural beauty. Trees also provide habitat for birds and animals. The following policies address tree preservation.
NE-70 To help preserve the natural environment and Redmond’s forested appearance, Redmond shall require the retention of sizable tree clusters, forested slopes, treed gullies and specimen trees that are of species that are long-lived, not dangerous, well-shaped to shed wind and located so that they can survive within a development without other nearby trees. Developments shall be designed and constructed to retain the trees in the earlier list in this policy. These trees should be identified and protected during land divisions and site plan review. Other trees may be removed to provide for project construction. Replacement trees should be planted on appropriate areas of the site to replace significant trees removed during construction.
Some areas, such as gullies and steep slopes, are poorly suited for development because of their natural limitations. They typically are also expensive to serve with public facilities. These areas often include significant numbers of trees. If these areas are designated for low intensity uses by the Comprehensive Plan, potential negative impacts on the community from developing these hazardous areas can be prevented and trees retained. This can help the property owners as well. By matching the Comprehensive Plan designation to the suitability of the land, expensive measures that to try to compensate for these natural limitations and try to serve intense uses with the needed infrastructure are avoided. These areas retain their character and are sensitively developed, making them valuable sites for appropriate uses.
NE-71 The Comprehensive Plan designations and zoning for forested slopes and treed gullies shall be consistent with retaining the tree cover in these areas.
Trees along waterways, wetlands and lakes provide many important functions. Along streams and rivers, trees shade the water, which reduces temperatures in the summer and helps salmon, steelhead and other fish to survive. Trees in gullies and along streams help slow stormwater and reduce erosion. The root systems of trees can also help stabilize streams, reducing erosion and stream migration. Leaves and insects falling from trees into streams, wetlands and lakes provide important food sources for fish and other aquatic creatures. The trees also provide habitats for birds and animals.
NE-72 Trees shall be preserved within stream, wetlands and lake buffers.
