From Section 5 Lino Lakes Plan

Transcription

1 p-gen3-03 Sample Comprehensive Plan Low-Impact Design Language Table of Contents: From Section 5 Lino Lakes Plan... 1 From Section 6 Lino Lakes Plan (Implementation)... 3 From Section 2 St. Croix County Plan... 4 From Section 3 St. Croix County Plan (Implementation)... 5 From Chapter 4 Savage Plan (Natural Resource Management)... 7 From Chapter 10 Savage Plan (Implementation) From Section 5 Lino Lakes Plan Water Resources Management Water resources management refers to managing stormwater in an ecologically sound manner that is consistent with the larger ecological vision for the community. Under the System Plan, using natural infiltration methods will be an underlying principle for managing stormwater on all public, and, where feasible, private lands. Natural Infiltration Method for Stormwater Management The natural infiltration approach to stormwater management relies on passive, overland routing of runoff, as opposed to storm sewers, engineered ponds, and other built structures. The nature approach offers a couple of distinct advantages over conventional systems: Introduced contaminants picked up by runoff are removed at the initial stages of water flowage rather than being transported to downstream locations and accumulating in wetland, lake, and river systems. This greatly reduces degradation to water quality and vegetative health in downstream systems. Stormwater flow rates and volumes more closely emulate natural conditions. This greatly reduces unnatural fluctuations in water levels in downstream systems (wetlands and lakes) and therefore reduces impacts to the natural condition of water systems and vegetation. Natural infiltration systems typically consist of four primary natural system components, as illustrated in figure 14. Each of the components function in sequence to treat the water before it enters wetlands, lakes, and rivers. Initially, stormwater runoff from the built environment is routed into swales or, more recently, raingardens, that are planted with native plants with deep root systems. These swales and raingardens provide initial infiltration and removal of pollutants, as well as convey runoff from developed areas and disperse it across upland and prairie systems. The upland systems (i.e., prairies and oak savannas) are the second component of this method, functioning to convey stormwater as diffused overland flow to the wetland systems that often link directly or indirectly to bordering lakes and rivers. These systems infiltrate a substantial portion of the annual surface runoff volume due to their very deep root system. They also provide additional solids settling and biological treatment. The wetlands are the third component of the natural infiltration method and provide both stormwater detention and biological treatment prior to runoff entering the lake and river systems. The final component is the lake or river, which provides stormwater detention, additional solids settling and biological treatment. wq-strm11-4

2 The use of a natural infiltration system also produces a much more natural hydrograph, resulting in lower peak flows and higher base flows relative to the hydrograph of a typical engineered flow rate control approach. Figure 15 is instructive in that it illustrates the difference between a flow rate control and ecological approach to stormwater management. Under the System Plan, the natural infiltration approach philosophy to managing stormwater is supported by the application of Best Management Practices that address common development circumstances likely to be encountered as the system plan is implemented. These practices define specific techniques that can be applied to different development scenarios to achieve stated environmental protection objectives. The Metropolitan Council s Urban Small Sites Best Management Practice Manual provides the basic underpinning for many of the techniques that will be employed wherever applicable as the development initiatives are undertaken. Note that newly emerging ecologically based techniques will also be applied to achieve desired ecological benefits. Specific techniques envisioned to have application for the park include: Minimization of impervious surfacing for parking lots and roadways, including the use of naturally surfaced areas for overflow/temporary parking. Use of infiltration systems (e.g., biofiltration systems, rain gardens, filter strips, swales, and slotted/flat curbs) as part of parking lot and hard surface designs. Use of infiltration techniques for managing roof runoff from buildings (e.g., downspout infiltration systems). Use of site grading techniques to achieve naturalized infiltration objectives. Use of contemporary erosion control techniques to prevent migration of soils during the construction process. Limiting the use of maintained turf to the more active use areas. Page 2 of 13

3 From Section 6 Lino Lakes Plan (Implementation) Within the next decade, many of the remaining open spaces will undoubtedly be impacted by development. The city is at a threshold point in terms of being able to influence its final built form. The natural open spaces that citizens hold in highest regard can only be preserved when the community development process is actually occurring, not after the fact. By taking an assertive role in that process, the city will have much greater assurance that the intrinsic quality of life values associated with protecting natural open spaces will be preserved for future generations. The conservation development process is relatively straightforward but also represents a significant shift from traditional approaches. Making this transition will require a good-faith partnership between the city and development community. A two-step strategy is recommended to enhance all parties satisfaction and confidence with this approach: 1. Develop a prototype process for conservation development through a hands-on working collaboration between the city and select developer(s) for a select development parcel(s). This would build upon the process defined in the Handbook for Environmental Planning and Conservation Development and any previous experiences the city has with this approach. 2. Institutionalize the refined conservation development process and adopt as the preferred approach to land development. This includes updating the Comprehensive Plan and zoning, subdivision, and platting ordinances to reflect this approach to land development. (Note: Standard regulatory land use controls would continue to provide regulatory strength behind the city s management of development. The key difference will be the city s emphasis on collaboration to achieve the highest public values from each development that occurs within the city.) (Note: Refer to Appendix A Five-Year System Implementation Plan for additional information.) The importance of this approach to development cannot be overstated. Lacking the flexibility that conservation development provides both the city and the developer, implementing the greenway system plan to its potential becomes much more remote. One of the key values of the conservation development process is that it allows the mixing and matching of strategies for protecting and managing natural resources, as defined in Section 3. Figure 18 illustrates the costbenefit to the city of a number of these strategies. As the graphic illustrates, gifted or donated land offers the highest cost-benefit to the city. Since philanthropy is often second to economy, this cannot be relied upon as the primary tool for setting aside open space. Second to this, conservation easements tend to offer the greatest cost-benefit to the city under the assumption that easements can be negotiated with a landowner or developer during the development process. Deed restrictions are also a low cost alternative, but the level of protection is at the discretion of the landowner, which can change from year to year. One of the strengths of the conservation development process is that it leverages the economies of the development itself to fund desirable public values. In other words, this approach works toward the greatest level of open space protection (and other public values) with the least amount of direct city capitalization. Page 3 of 13

4 From Section 2 St. Croix County Plan GOAL 1: PROTECT THE RURAL CHARACTER OF ST. CROIX COUNTY 1A. Maintain a high quality environment. 1B. Protect and enhance the natural beauty of the county. 1C. Provide adequate green space throughout the county and in individual developments. 1D. Vary the density of development according to varying site conditions and the availability of appropriate facilities and services. 1E. Encourage compact development through expansion and infill of existing developed areas. 1F. Encourage cluster developments to conserve natural resources and open spaces. 1G. Foster private land stewardship of individual properties and developments by landowners, developers and property managers. 1H. Avoid visual pollution caused by poor design or management of buildings and structures. 1I. Promote a positive sense of community and community image. GOAL 2: PROTECT AND ENHANCE THE NATURAL RESOURCES 2A. Protect, maintain and improve the quality and quantity of groundwater and surface water resources that originate or flow through the county. 2B. Conserve and protect wetlands and their natural functions. 2C. Conserve and protect floodplains and shorelands and their natural functions to avoid the impacts and costs of their development. 2D. Conserve and protect woodlands and grasslands and their related benefits for wildlife habitat, open space and air quality. 2E. Protect steep slopes and control erosion and sedimentation from development activities that can impact water quality, public facilities and neighboring property. 2F. Identify and protect environmental corridors where multiple natural features are located and provide a number of natural resources values. 2G. Conserve open space and protect unique open space areas. 2H. Promote sound soil and water conservation practices for both farm and non-farm activities. 2I. Protect and maintain air quality. 2J. Guide development to locations and conditions that minimize adverse impacts to natural resources. Page 4 of 13

5 From Section 3 St. Croix County Plan (Implementation) Planned gross density Create process and reporting to keep track of the density of development so that the ultimate, final, or complete development of existing parcels, in aggregate, does not exceed the planned gross density Immediately Planned Conservation Site Design Create process and reporting to keep track of the amount of conservation site design development relative to traditional development to evaluate whether this tool is being used to meet the goals and objectives. Immediately Conservation site design development In new zoning ordinance: 1. An overlay district which allows appropriate density bonuses for conservation design 2. Density transfer to allow larger contiguous open spaces while maintaining overall density 3. Requirement to retain at least 65% of the subdivision in permanent open space 4. Require design to be compatible with the rural character and environmental features of the area Immediately Conservation site design development Amend subdivision ordinance with: 1. Design standards for conservation design 2. Matching requirement to zoning requirement to retain at least 65% of the subdivision in permanent open space 3. Requirement for design to be compatible with the rural character and environmental features of the area 4. New road design standards for conservation design Within one year of county adoption of revised zoning ordinance Open space Protect and manage identified unique open space areas, through the cooperation of state and federal agencies, local governments, conservation groups and landowners Ongoing Lower St. Croix National Scenic Riverway Management 1. Work with state agencies to support the development and enforcement of regulations that protect the Lower St. Croix National Scenic Riverway. 2. Cooperate with the Lower St. Croix River Management Commission and others in comprehensive riverway planning and management efforts. Ongoing Prairie restoration Encourage the restoration of prairie or grassland ecosystems through cooperative efforts of the state, county and federal agencies, and landowners Ongoing Shoreland Habitat Management Page 5 of 13

6 1. Work with state agencies in using available tools such as lakes classification and shoreland ordinance revisions to provide greater shoreland habitat protection on sensitive shorelines and lakes. 2. Promote the use of shoreland habitat restoration as a best management practice. 3. Work with state agencies, Lake Districts and Lake Associations to support the enforcement of regulations that protect and restore shoreland habitat. Ongoing Page 6 of 13

7 From Chapter 4 Savage Plan (Natural Resource Management) Water Quantity Goal: Manage public capital expenditures that are necessary to control excessive volumes and rates of storm water runoff. Goal: To prevent flooding from surface water flows. Policies: The City of Savage shall require retention of storm water runoff to the extent necessary to be consistent with the CWRMP. Detention of upstream runoff has been the basis by which existing trunk drainage facilities have been constructed. As is part of any new or redeveloped activity, adequate runoff rate control measures must be incorporated into the design to ensure that storm water runoff rates will be in conformance with the rates outlined in the CWRMP. Wetlands shall be protected within the City boundaries to assure that the value of the wetland in relation to its surface water quantity benefits are not significantly impacted. It is the intention of the City to utilize natural ponding areas, such as wetlands, for the impoundment and treatment of surface water run-off and these natural ponding areas are preferred over impoundments constructed in upland areas provided they are classified to be used for runoff management. The design of all major storm water storage facilities shall attempt to accommodate a critical duration event with a 1 percent chance of occurrence in any given year (100-year storm event). These facilities include lakes, ponds, and their outlets. New storm sewer systems shall be designed to accommodate discharge rates associated with a critical duration event with a 10 percent change of occurrence in any given year (10-year storm event). It is the City s position that it is impractical and financially not feasible to construct drainage systems to accommodate run-off from rainfall events having lesser probabilities of occurrence than those identified above. In newly developing watersheds, measures shall be taken to limit postdevelopment peak discharge rates to less than or equal to pre-development rates for the 2-, 10- and 100-year rainfall events. Post-development discharge rates for the 100-year storm event shall not exceed 0.10 cfs per acre of tributary drainage area for any new development within the City. The City may grant exception to this policy when its implementation would conflict with the goals of the CWRMP. The development of enhanced infiltration practices should be implemented wherever it is practical and reasonable to do so, provided that past and existing land use practices do not have a significant potential to contaminate storm water runoff. Landlocked depressions which presently do not have a defined outlet and do not typically overflow may be provided a positive outlet provided it is in conformance with the approved storm water management plan. To be in conformance with the CWRMP, it must be demonstrated that increased flows resulting from the construction of an outlet from a previously landlocked basin will not significantly increase runoff rates into downstream watersheds and/or Page 7 of 13

8 municipalities. It is the intention of the CWRMP to allow the construction of outlets from landlocked basins that are designed in such a manner that downstream subwatersheds and/or municipalities are not significantly affected by the outlet construction. Since completion of the CWRMP, one outlet has been constructed, and two more outlet structures will be completed in The City of Savage will adopt the revised shoreland regulations as established by the Minnesota DNR. The City of Savage will require developers to submit storm water management plans prior to site development. As development takes place, the City of Savage intends to acquire easements over significant hydrologic features such as storm water storage areas, wetlands, flood plains, and conveyance systems. Water Quality Goal: Maintain or improve the quality of water in lakes, streams or rivers within or immediately downstream of the City of Savage. Policies: In the design and construction of all new or modification of existing storm water conveyance systems, pretreatment of storm water runoff to Nationwide Urban Runoff Program standards must be provided prior to discharge. Since completion of the CWRMP, this policy has been adopted by the City. The City will conform to the Interim Strategy to Reduce Nonpoint Source Pollution to All Metropolitan Water Bodies of the Metropolitan Council (1992), that addresses the proper management of storm water discharges. Generally speaking, this strategy requires the use of MPCA Urban Management practices as outlined in their publication Protecting Water quality in Urban Areas (1991), utilizing Nationwide Urban Runoff Program (NURP) standards in the design of retention and treatment basins, and the adoption of shoreland ordinances in conformance with DNR directives. Since completion of the CWRMP, this policy has been adopted by the City. The City of Savage will implement the MPCA Best Management Practices as part of the City code. Since completion of the CWRMP, a street sweeping plan has been implemented requiring City streets to be swept twice a year. The City of Savage will require the inclusion of oil skimmers in the construction of new pond outlets, and add skimmers to the existing system whenever feasible and practical. The designs shall provide for skimmers that extend a minimum of 4 inches below the water surface and minimize the velocities of water passing under the skimmer to less than 0.5 feet per second for rainfall events having a one-year return frequency. The City will include provisions for coarse sedimentation and skimming of oil and floatable materials prior to allowing any discharge to the Minnesota River. This requirement will apply in all cases except where it is deemed not feasible or not practical to do so. Considerations for variance to this policy will only be made in cases where the direct drainage area is limited in size and the probability that Page 8 of 13

9 a spill or significant pollutant discharge from the area to areas outside the City would be extremely unlikely. The City will develop and implement a program aimed at fostering responsible water quality management practices by its residents. The City will make an effort to educate the public by distributing information to its residents on responsible practices they should employ to protect water resources within the community. The program shall also educate residents on the proper use of fertilizer and if appropriate, encourage residents to use fertilizer having no phosphorus content. The City will work with Scott County to develop a program to ensure that solid or liquid waste is disposed of properly. This program will include providing information to homeowners on property disposal and/or use of yard waste in an environmentally responsible manner. It will also educate its residents on the proper disposal of household hazardous waste, including waste oil, paints, and solvents. The City will work with Scott County toward securing locations within the City limits where household hazardous waste may be dropped off. An informational program for homeowners will be broadcast on local cable TV. The City will require homeowners with properties adjacent to water resources to establish a vegetative buffer strip at least 16.5 feet (one rod) wide at the shoreline per City ordinance. This strip should consist of legumes or other perennial grasses to limit erosion and nutrient transport across the buffer strip. Since completion of the CWRMP, the City has adopted a policy requiring a foot buffer strip and signs clearly demarcating the buffer. The City has adopted a sanitary sewer plan to address the issues concerning individual sewage treatment systems. This Plan includes an on-site septic system inspection and evaluation program to monitor and evaluate the condition and treatment functions of these systems. The City will clean all sump catch basins or sump manholes at least one time annually, and more often if it is demonstrated that more frequent clean out is necessary. The City will develop a retention/treatment basin clean-out and maintenance plan that will address maintenance to the extent feasible and practical. The goal of this plan will be to assure that the City s retention and treatment basins will have the capability to retain and treat storm water in future years. Since completion of the CWRMP, the City has performed a pond inventory and is in the process of developing a stormwater pond maintenance plan. The City will protect wetlands to assure that their fish and wildlife, environmental quality, and socio-economic values are maintained. The City will develop and implement a water quality monitoring program capable of establishing that the storm water treatment basins constructed within the City are not only designed to nationwide urban runoff standards, but also meet the anticipated design removal efficiencies based on actual monitoring of the system. In addition, this monitoring program will include the monitoring needs for the Savage Fen Wetland Complex and Eagle Creek areas as indicated in the AUAR Mitigation Plan. This program will be carried out to the extent deemed necessary and reasonable by the Savage City Council. The scope associated Page 9 of 13

10 with this water quality monitoring program will also be developed, based on the feedback received from the various WMOs within the City, as well as the Minnesota Department of Natural Resources. Since completion of the CWRMP, a Water Quality Monitoring Program has been initiated for five water bodies and Eagle Creek. The City of Savage will require developers to submit storm water management and erosion control plans prior to site development. The City discourages the use of septic tanks and soil absorption systems, however, if no other alternative exists, such systems may be installed, provided they are installed and maintained consistent with the standards and regulations adopted by the Minnesota Pollution Control Agency and the Minnesota Department of Health. All storm water runoff directed to water bodies that are classified for functions other than runoff management, shall be routed through ponds for treatment before discharge into these water bodies that are classified for intended uses other than runoff management. The City of Savage will encourage property owners having lots containing shoreland to utilize no phosphorous fertilizers on these lots unless it is demonstrated a need for such application is necessary. Erosion Goal: To prevent erosion and sedimentation to the maximum reasonable extent. Policies: The City has created and is implementing an aggressive Construction Site Erosion Program. The program has been very successful in minimizing construction site erosion within Savage, and the Savage program is being used as a model by the MPCA, Scott SWCD, Prior Lake Spring Lake Watershed District, and by several other cities. Erosion and sedimentation control plans shall be reviewed and enforced by the City for all new developments. These plans shall conform to the general criteria set forth by the Minnesota Construction Site Erosion Control Handbook or practices outlined in the Minnesota Pollution Control Agency Division of Water Quality Document Protecting Water Quality in Urban Areas. The City will adopt a soil loss limits nuisance ordinance for construction sites and agricultural lands with enforcement of agricultural lands to be consistent with Minnesota Statute 1968, Chapter , excessive soil loss. The City may prohibit work or require setbacks in areas having steep (25 to 33 percent) or very steep ( 33 percent) slopes and high erosion potential where the impacts of significant erosion cannot be protected against or mitigated in accordance with the City s erosion control ordinances. The City will administer a program for controlling sediment erosion from single family home construction sites. The appropriate ordinance revisions will be made to enforce this program. Implement the Credit River Erosion Control Plan. Since completion of the CWRMP, the City has created and is implementing Capital Improvements Page 10 of 13

11 Projects along the Credit River. In 1996, 42 areas were identified as contributing major erosion to the Minnesota River, and requiring improvements. Since 1996, 12 of the 42 areas identified along the Credit River have been or are currently being corrected. Erosion Control Plans shall be submitted for approval if more than one acre of land is being graded or if the site is highly erodible. Page 11 of 13

12 From Chapter 10 Savage Plan (Implementation) Bluffland Protection/Woodland Protection The City through the use subdivision regulation will restrict development in areas of sensitive environmental resources. This includes areas with slopes greater than 25 percent, contiguous forest cover, wetlands and floodplains. The future land use plan delineates areas of forest and wetland conservation and provides a mechanism to identify areas of significant environmental value. Within these conservation areas, development proposals will be reviewed with the intent to preserve woodland and wetland areas to the maximum extent possible. To achieve the maximum protection of these conservation areas specific development guidelines will be developed and implemented as part of the City s subdivisions regulations and ensure conformance between this Comprehensive Plan and regulatory documents. These regulations will include setbacks, erosion control measures, buffer and other design-based guidelines. The overall goal of these guidelines will be to ensure adequate economic return on development while ensure long-term environmental protection. Residential Development To successfully implement the residential policy stated in this Plan and to support the City s desire to create a community of neighborhoods through the encouragement of traditional neighborhood design, the following criteria should be incorporated into the City s zoning and subdivision regulations. Reducing minor streets from 32 feet wide to 28 feet wide in neighborhoods of single family housing. This is intended to encourage traffic speeds that are appropriate for the situation, to create a more attractive environment, to reduce costs, to reduce water runoff and to reduce summer heat buildup. Requiring the construction of sidewalks along both sides of all streets. Providing bicycle and pedestrian connections throughout the community according to the Comprehensive Park and Trail Plan. Reducing the minimum width of single-family residential lots. Interconnecting residential streets to promote safe and easy movement and socializing, and to reduce the traffic pressure on collector and arterial streets. Cul-desac streets will be discouraged except in instances when it is not possible otherwise to serve an area of land (such as a peninsula with wetlands on three sides). Suggesting that developers include front porches on new houses and allowing front porches a 6- foot reduction from the front yard setback requirement. Cluster development will be encouraged within the developing South Savage Sub-area to preserve important rural character, protect sensitive natural resources and minimize the extent of impact resulting from development upon the landscape. Single-family areas will be interconnected by streets and sidewalks with multiple family residential areas and with commercial developments. This is intended to reduce dependence on the automobile, reduce social segregation in the community and improve access to future bus transit lines. Business Park Development The City of Savage will create a Land Use Plan Map district and a Zoning Map district that allows office buildings, office-showroom buildings, light industry, research and development businesses, and related or supportive service businesses as primary uses. Zoning and subdivisions regulations will be developed to ensure Business Park development proposals protect major environmental features, minimize impacts to adjacent neighbors and avoid other land use impacts Page 12 of 13

13 associated with business development. Specifically, the City s subdivisions regulations will be amended to include buffer requirements, erosion control measures, woodland preservation and lightning design standards. In addition, Business Park development adjacent to Eagle Creek must provide open space; building locations and landscaping that complement, supplement and protect the public open space along the creek. Surface water drainage and ponding must conform with City plans to protect water quality and water temperature in the creek. Page 13 of 13