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HomeMy WebLinkAboutResolution No. 454-04 - RESOLUTION • WHEREAS, R.C.O. § 77A provides for the creation of a Storm Water Utility; and WHEREAS, the Storm Water Utility provides for the implementation of storm 'water, management activities that are within the City's governmental authority to protect the environment and to promote the public health, safety, convenience and general welfare of its citizens and visitors; and, WHEREAS, the Common Council of the City of Rochester has adopted by resolution the October, 2003, Storm Water Utility Fee Credit Manual to provide Credits as an appropriate means of adjusting Fees for Non-Residential property owners, thereby recognizing that effective Structural or Non-Structural Best Management Practices can reduce the City's storm water management burden; and WHEREAS, some residential developments maintain private ponds to manage their site-specific storm water and are not eligible for credit due to the Storm Water Utility Ordinance requirement that Credits cannot result in a Fee less than the Residential Fee; and WHEREAS, an alternative approach is needed to provide equity to residential customers who are also responsible for private storm water ponds; and • WHEREAS, the Rochester Public Works Department has prepared "Policies and Procedures to Address Private Residential Ponds" that provide options for transfer or maintenance of private residential ponds to the City if rational eligibility criteria are met. NOW, THEREFORE, BE IT RESOLVED by the Common Council of the City of Rochester that the City does hereby approve the adoption of the "Private Residential Pond Maintenance Transfer Policy and Application Request" prepared by the Director of Public Works, dated August, 2004, and attached hereto. PASSED AND ADOPTED BY THE COMMON COUNCIL OF THE CITY OF ROCHESTER, MINNESOTA, THIS 2077Y DAY OF e5e?0e/)1B6A_9_ , 2004. FtE'SIDEN-rOF SAD COMMON COUNCIL ATTEST: 'C1111 CLERK • APPROVED THIS 2/,57- DAY OF_�725122 F4Z , 2004. MAYOR OF SAID CITY (Seal of the City of Ro,chester':Minnesota} Res2000/Adopt.S W UPbndTra 7f6rPo licy i 1 i Keeping The City of Rochester' s 1 le Storm Water Utility Private Residential Pond Maintenance/Transfer Policy and s Application Request StonWater August 2004 M A N ♦ 6 E M E N T Introduction The Storm Water Utility Ordinance does not provide opportunities for Residential Fee Credit. This is because the Residential Fee represents.the minimum fair share payment from developed parcels to fund the City's storm water management activities. Although Non-Residential customers may apply for Fee Credit,the Fee for any Non-Residential parcel may not be reduced below the Residential Fee amount. In the absence of being able to apply for Residential Fee Credit,this policy addresses an alternative manner to deal equitably with owners of private Residential ponds. Under-this policy,owners of private residential ponds have the opportunity to apply for transfer of their ponds to the City, if current design and construction standards are met. Alternatively, owners of substandard ponds may make application to the City to be considered for ongoing maintenance by the City,with costs assessed back to the individual property owners over time. If owners of private residential ponds are interested in taking advantage of either opportunity, application must be made no later than December 31,2008. Application procedures and an application request form can be found at the end of this document. History The City's goal in developing the Storm Water Management Plan in the late-1990's was to create a regional storm water pond network. This approach was designed to maximize community-wide storm water quality benefits while minimizing the number of ponds and their ensuing maintenance obligations. After the completion of the Storm Water Management Plan,the City Council opted to move forward with a voluntary, interim program(until such time as a Storm Water Utility was adopted),whereby developers had three primary options: 1. Pay a Storm Water Management Plan Area Charge(Charge) into a fund for the construction of public regional storm water management ponds, or 2. Construct an on-site public regional (Regional) storm water management pond(for areas draining,50 developable acres or more lying within the property), or 3. Construct an on-site private(Private)storm water management pond(for areas draining less than 50 developable acres lying within the property). Some developers opted to construct Private ponds in lieu of paying a Charge, fully understanding they had a permanent obligation to operate,maintain,and repair the pond to insure provision of the storm water management benefits of their pond. (In a few cases, developers did not have the option of paying a 1 Charge in lieu of building the pond because the property drained directly to areas outside the City limits or there were no options for downstream regional ponds.) Had the developers not opted to build Private, development-specific ponds in lieu of paying the SWMP Charge when the Charge was feasible,the City could have built larger,more efficient and manageable ponds resulting in a smaller number of ponds than are present at this time. New Policy Rationale There are several reasons why it is rational for the City to adopt the policies and procedures outlined in the next section to take ownership of private residential ponds or to provide the maintenance for those ponds. 1. With the adoption of the Storm Water Utility, owners of private,non-residential ponds are in a position to receive Fee Credit for the maintenance they perform that provide a financial value to the City's overall storm water management program and objectives. Due to restrictions in the structure of the Utility, owners of private Residential ponds are not eligible for Fee Credit. This creates an inequity between customers. 2. Ponds built to serve every development provide a public water quality and quantity management benefit,regardless of who paid to construct it or who maintains it. The transfer of a pond that has been constructed to standards to the City equates to the contribution of SWMP Charges to the regional pond construction account. Both cases require an outlay of funds by the developer to meet their initial obligation to provide an integrated and functional storm water management system. Since the City is obligated to maintain public ponds built with SWMP Charges, a parallel argument could be made that the City should also maintain private ponds built with private funds since the water quality benefits accrue to the entire City under the new storm water permit. 3. With the adoption of the Storm Water Utility,private storm water management ponds serving residential developments will not be an option,except under extenuating circumstances, such as proximity to a waterway or drainage outside City limits. 4. Under the new Storm Water Permit,the City will likely face a cost burden to inspect private residential and non-residential ponds(regardless of who maintains them). It's unclear what level of staff effort will be needed to get private pond owners to follow-through on their maintenance obligations, but the potential loss of Fee Credit should be an incentive to non-residential customers. There is no similar financial incentive for residential customers to maintain their ponds. If non-compliance with grading plan erosion and sediment control requirements are an indication, it may take a considerable amount of staff time and ultimately Council action to get some Owners to uphold their obligations. This may be especially difficult when working with multiple Owners(i.e., Home Owner's Associations). Nevertheless, under state nuisance abatement statutes,the City does have the authority to have the deficiencies in the facilities corrected and assessed back to the benefiting Owners should they neglect to properly care for their facilities. 5. Where the City is responsible for maintenance,the regular inspection program will lead to preventive maintenance work that,as is true for all infrastructure assets, ultimately results in lower life cycle costs than emergency repairs caused by deferred maintenance or total neglect. New Policies and Procedures Based on the evaluation of the City's past and present storm water management policies and practices and the current status of the pond network,the following policies and procedures will be used to determine the eligibility of a private residential pond for transfer to or maintenance by the City of Rochester. 2 r 1. Private Residential Ponds-Transfer to City. Private storm water ponds serving only residential developments that meet the City's design and construction requirements inherently have no additional liability to the City than its public storm water ponds. Owners of these ponds may make application for transfer to the Public Works Department to demonstrate that their pond meets the City's design and construction requirements that were outlined on the Grading Plan Checklist in effect at the time of the pond's construction. For ponds built before 7/29/98,the requirements outlined in the 7/29/98 Grading Plan Checklist must be met. These ponds will be considered for transfer to the City if sufficient written documentation on the following criteria is provided to the City by the Owner or the Owner's Consultant: a. The pond is located on an adequately sized, separate parcel of property with clear title that can be conveyed to the City, along with access easements for ongoing maintenance. b. An evaluation of the pond condition and functionality has been made using the applicable Grading Plan Checklist to identify deficiencies. Depending on their severity, some deficiencies may preclude the pond from being eligible for transfer to the City. Owners have the option of correcting deficiencies at Owner's expense. If Owners wish to correct all deficiencies,they can then be eligible for pond transfer consideration. In this case,the Owners have the option of paying directly for upgrades or of being charged a Special Assessment over a period of 10 years to pay for the cost of upgrades completed by the City. All Owners must execute an Assessment Agreement if they desire to have the costs to be paid in that manner. c. As-built construction drawings prepared by a licensed professional, at the cost of the Owner, are provided that show site contours (at 2-foot intervals)indicating the underwater elevations of the pond and the elevations of the land surface that surrounds the pond. d. Documentation that sediment was removed'to restore the original design capacity of the pond after development construction was completed or prior to transfer to the City. e. Post-construction pond maintenance has been provided according to all standard and customary maintenance requirements as defined by the City(typically contained in executed Maintenance and Ownership Agreements, as outlined in Attachment 1). The Owner must provide documentation of all maintenance and repair activities to the City. f. Documentation that the pond does not degrade the quality of any nearby wetlands, fens, waterways, as it relates to water quality,hydrologic recharge capacity, or habitat support. Ponds that have been constructed to address shoreland and floodplain requirements are not eligible for transfer as storm water management ponds. g. Field verification by the City confirms the condition and functionality of the pond as described in the documentation provided by the Owner. 2. Private Residential Ponds-Maintenance by City. Private storm water ponds serving only residential developments that do not meet the City's design and construction requirements as outlined on the Grading Plan Checklist in effect at the time of the pond's construction have higher maintenance needs and a higher liability risk for the City due to safety considerations and will remain private. (For ponds built before 7/29/98,the requirements outlined in the 7/29/98 Grading Plan Checklist must be met) However, Owners of these ponds may make application to the Public Works Department to be considered for ongoing maintenance by the City. The advantage to the Owners in this case is the opportunity to have the City provide inspection and maintenance services with payment for services assessed back to the individual property Owners over time, as opposed to having the obligation to coordinate,contract for, and pay for all costs at the time maintenance services are needed and provided. The city Engineer will determine the eligibility of pond maintenance by the City after the following documentation provided by the Owner or Owner's Consultant has been evaluated by City staff: 3 a. An evaluation of the pond condition and functionality will be made using the applicable Grading Plan Checklist to identify deficiencies. Depending on their severity, some deficiencies may preclude the pond from being eligible for City maintenance. Owners have the option of correcting deficiencies at Owner's expense. If Owners wish to correct all deficiencies, they can then be eligible for pond transfer consideration, as outlined in #1, above. In this case,the Owners have the option of paying directly for upgrades or of being charged a Special Assessment over a period of 10 years to pay for the cost of upgrades completed by the City. b. The Owner indicates a willingness to grant a permanent Public Drainage or Drainage and Utility easement for the pond and an Access Easement for its maintenance access corridor. c. The evaluation of pond condition and functionality provides a public storm water quantity, storm water quality,or safety benefit. d. The pond receives storm water run-off from a public street. e. The pond storage capacity can accommodate a 10-year, 24-hour storm event for the area that drains to it without emergency overflow. f. The Owner agrees to a Maintenance Agreement that includes a hold harmless clause in favor of the City for site safety. g. All Owners with property rights interest in the pond must execute an Assessment Agreement providing for the levying of periodic Special Assessments reflective of the City's actual cost to inspect and maintain the private ponds for the Owner. h. Field verification by the City confirms the condition and functionality of the pond as described in the documentation provided by the Owner. Private residential ponds evaluated by City staff for the criteria listed above will be rated as either Acceptable or Not Acceptable. The basis for rating each pond has been established by the City Engineer and,through its inclusion in this document,adopted by the City Council. 3. Private Residential Ponds—No Change. Private ponds serving only residential developments that do not meet the City's design and construction requirements as outlined on the applicable Grading Plan Checklist and that cannot meet the maintenance eligibility criteria listed above will not be eligible for transfer to the City or for ongoing maintenance by the City. ,They will remain private with the Owner's obligation to provide ongoing maintenance.Additionally,residential customers with private ponds will NOT be eligible to receive Fee Credit to be applied to the Storm Water Utility Fees. HAstormwater\Residential Pond Transfer-Maintenance Policy.doc 4 i ATTACHMENT 1 For the purposes of this Agreement, the term maintenance for the storm water facilities shall mean: a) The operational performance of the ponds shall be consistent with the storm water quantity (volume) and quality(detention time)parameters established by the original pond design as approved by the City, and b) The appearance of the pond shall be in compliance with applicable City Ordinances related to the control of weeds and grasses and the removal of debris and litter. c) The recommended intervals for regular maintenance shall be: i) Semi-Annual mowing ii) Annual inspection of soil berms and structures iii) Repairs as necessary iv) Remove sediment from storm sewer inlets and outlets every 2-5 years v) Remove sediment from pond to maintain storage volumes every 5-10 years vi) Litter removal,noxious weed and brush removal, and rodent control on an ongoing basis d) Each of the above items shall also be consistent with the requirements under the Wetland Conservation Act for any wetland corridors affected by the storm water facility. HAstormwater\Residential Pond Transfer-Maintenance Policy.doc • 5 i APPLICATION REQUEST FOR PRIVATE RESIDENTIAL POND TRANSFER OR MAINTENANCE Owners of Private storm water ponds serving only residential development may make an application for transfer(Part 1)or maintenance(Part 2)to the Rochester Public Works Department, in care of: Director of Rochester Public Works 201 4th St. SE, Room 108 Rochester, MN 55904 PLEASE USE AND ATTACH THE APPLICATION COMPLETENESS CHECKLIST INCLUDED WITH THIS APPLICATION REQUEST AS A COVER SHEET FOR THE FOLLOWING SUBMITTALS. THE OWNER AND THE OWNER'S CONSULTANT MUST SIGN THE COMPLETENESS CHECKLIST TO CERTIFY THE_COMPLETENESS AND ACCURACY OF THEIR APPLICATION. Part 1 —Transfer to City Private storm water ponds serving only residential developments will be considered for transfer to the Public Works Department if the Owner can demonstrate that the pond meets the City's design and construction standards that were that were outlined on the Grading Plan Checklist in effect at the time of the pond's construction. For ponds built before 7/29/98, the requirements outlined in the 7/29/98 Grading Plan Checklist must be met. A. The Owner or the Owner's Consultant must provide documentation to the Rochester Public Works Department to verify the following: I. The pond meets the City's design and construction standards as outlined on the Grading Plan Checklist requirements in effect at the time the pond was constructed, including drainage area and site access. (For those ponds build prior to 7/29/98,requirements outlined in the 7/29/98 Grading Plan checklist must be met.) 2. Quantities of sediment removed(with the dates of removal)to restore the original desiruction was completed and prior to gn capacity of the pond after development related construction transfer to the City, along with the base elevations of the pond in its current condition. 3. The pond does not negatively impact any nearby wetlands, fens, waterways, shorelands, and floodplains. B. The Owner must also supply the following documents after a determination of acceptability for transfer by the City Engineer: I. Clear title for the separate parcel of property on which the pond is located. (The cost of parcel separation and title conveyance to be born by the Owner.) 2. Access easements, meeting the design standards outlined in the applicable Grading Plan Checklist,to the pond for ongoing maintenance. 3. Two copies of as-built construction drawings,prepared by a licensed professional at the cost of the Owner,that show site contours(at 2-foot intervals)indicating the underwater elevations of the pond and the elevations of the land surface surrounding the pond. 4. Post-construction pond maintenance and repair records showing that all standard and customary maintenance requirements as defined by the City were implemented. (These requirements are either outlined in an executed Maintenance and Ownership Agreements or as outlined in Attachment 1.) C. An on-site inspection by the City must be made to confirm the condition and functionality of the pond as described in the documentation provided to the City by the Owner. 6 � (I Part 2—Maintenance Agreement with the City A. The City will consider ongoing maintenance for private residential ponds that do not meet the City's applicable design and construction standards after evaluation of the following documentation submitted by the Owner or the Owner's Consultant to the Rochester Public Works Department: 1. An evaluation of the pond condition and functionality using the Grading Plan Checklist requirements in effect at the time the pond was constructed. For those ponds build prior to 7/29/98,requirements outlined in the 7/29/98 Grading Plan checklist must be met. Both the conditions meeting standards and those not meeting standards must be described. Demonstrate that the pond condition and functionality provide a storm water quantity, storm water quality, or safety benefit to the City. (Based on the types and severity of the deficiencies,the Director of Public Works will make a determination on the eligibility of the pond for City maintenance) NOTE.- Owners have the option of correcting deficiencies, at Owner's expense, to be considered for City maintenance. ff Owners wish to correct all deficiencies, they may then be eligible for pond transfer consideration, as outlined in Part 1, above. 2. The public streets direct storm water run-off to the pond. 3. An evaluation to identify whether the pond storage capacity can accommodate a 10-year, 24- hour storm event for the area that drains to it without emergency overflow.The data and methodology used to determine the actual level of protection provided by the pond must be submitted. 4. A description of pond upgrade opportunities to provide increased future downstream benefit for the City,given its location and parcel size. 5. After a determination of acceptability for maintenance by the City Engineer,the Owner must also supply the following documents: a. Permanent Public Drainage or Drainage and Utility easements for the pond and an Access Easement for its access corridor have been provided. b. An executed Maintenance Agreement that includes a hold harmless clause favorable to the City for site safety. c. Information necessary for the City to prepare an Assessment Agreement that allows the City to periodically levy Special Assessments against the Owner(s)' property for pond maintenance performed by the City. d. An executed Assessment Agreement prepared by the City for the costs associated with pond maintenance. B. If the Pond Maintenance Application is acceptable, an on-site inspection must confirm the condition and functionality of the pond as described in the documentation provided to the City by the Owner. HAstormwater\Residential Pond Transfer-Maintenance Policy.doc 7 APPLICATION REQUEST FOR PRIVATE RESIDENTIAL POND TRANSFER OR MAINTENANCE APPLICATION COMPLETENESS CHECKLIST The Owner or Owner's Consultant must complete and attach these 2 pages as the cover pages for the required documentation prior to submittal. Sections highlighted in gray are to be completed by the City only. Incomplete applications packets will be returned without further review and processing. We hereby certify that this application is complete and accurate to tlae best of our knowleda e. Owner's Name(print) Signature Date Owner's Consultant Name(print) Company Name (print) Owner's Consultant Signature Date Part 1—Transfer to City Please check each box after confirming the associated information is included in the application packet. ❑ All pond requirements have been met, as outlined in the attached Grading Plan Checklist that was in effect when the pond was constructed, including drainage area and site access. Date of pond construction: Date of attached Grading Plan Checklist: ❑ Quantities of sediment removed(with the dates of removal)to restore the original design capacity of the pond after development construction was completed and prior to transfer to the City, along with the base elevations.of the pond in its current condition. ❑ Information documenting that the pond does not negatively impact any nearby wetlands, fens, waterways, shorelands, and floodplains. ❑ A map showing actual or conceptual boundaries and metes and bounds splits for the pond and its associated facilities. ❑ Two copies of as-built construction drawings,prepared by a licensed professional at the cost of the Owner,that show site contours (at 2-foot intervals) indicating the underwater elevations of the pond and the elevations of the land surface surrounding the pond. ❑ Post-construction pond maintenance and repair records showing that all standard and customary maintenance requirements as defined by the City were implemented. (These requirements are either outlined in an executed Maintenance and Ownership Agreements or as outlined in Attachment 1.) ❑ A petition to request pond transfer to the City signed by all benefiting owners with a fiduciary responsibility for the facility. An on site inspection by the City must be made to corifum the condition and functionality of t11e pond as described m;the documentation provided to the City by the Owner ` 13 bate of on site inspection s 2 Name of RPW staff conducting,inspection 3 Deficiencies identified :� F; t 4 Date of follow up inspection 5 Nam e of inspector conducting follow up inspection 6 Pond in confoxmarice� Yes No Transfer to City Approved Denied Date En Signature ofDirector ofPublic Worl,s ._ a After approval,the applicant must provide clear title for the separate parcel of property on which the and is locate along with an access easement to the pond for ongoing maintenance. p d' Part 2—Maintenance Agreement wifh the City Please check each box after confirming the associated information is included in the application packet. ❑ An evaluation of the pond condition and functionality using the attached Grading Plan Checklist that was in effect when the pond was constructed. Both the conditions meeting standards and those not meeting standards must be described. The pond condition and functionality must provide a storm water quantity, storm water quality, or safety benefit to the City to be eligible. Date of pond construction: Date of attached Grading Plan Checklist: ❑ The public streets direct storm water run-off to the pond. ❑ An evaluation that identifies whether the pond storage capacity can accommodate a 10-year, 24-hour storm event for the area that drains to it without emergency overflow,including the data and methodology used to determine the actual level of protection provided by the pond. ❑ A discussion of pond upgrade opportunities to provide increased future downstream benefit for the City given its location and parcel size. ❑ A petition to request pond maintenance by the City signed by all benefiting owners with a fiduciary responsibility for the facility. Pond Maintenance Apphcat�on Acceptable � Not Acceptable If the Pond Maintenance Application is acceptable, an on site snspect�on must confirm;the condition and r functionality of the pond as descnbedan the documentation provided to;the City by the Owner 1 ' Date ofon site insp ecton € � 2 Name of RPW staff conductugi.jnspection Deficiencies°identified: , % 7 % fr 3 • 4 Date of follow up mspectton 5 Name of inspector conductingfollow:up mspechon 6 Pond m conformances Yes No s Private Residential Pond�lVlamtenance by the City %ApproYed Denied- Date Signature of Director.of PubLc Works . After approval,the applicant must coordinate with the Public Works Department to execute the following City prepared documents: ❑ Permanent Public Drainage or Drainage and Utility easements for the pond ❑ An Access Easement for its access corridor ❑ A Maintenance Agreement that includes a hold harmless clause for site safety ❑ An Assessment Agreement for special pond maintenance assessments HAstormwater\Residential Pond Transfer-Maintenance Policy.doc i Private Residential Ponds-Maintenance by City .RATING SHEET Private residential ponds evaluated by City staff to determine if it is Acceptable or Not Acceptable for maintenance by the 0 City. The steps to complete the determination for each pond follow. STEP 1 No=0; Yes = 1 Acce tabili Criteria 1. The and receives storm water run-off from a ublic street Score 2. The pond storage capacity can accommodate a 10-year,24-hour storm event for the area that 0 1 drains to it without emergency overflow If either item listed above receives a"0",the pond is Not Acceptable for maintenance by the City unless corrected. If both items receive a"1",continue to Step 2. STEP 2 ITEMS 1 &2: 0=no conformance or benefit; 1 =very poor; 2=poor; 3 =good;4=very good ITEM 3: 1 =not serious; 2=serious;3 =very serious M ty Criteria Score ndition and functionality(based on applicable GradingPlan Checklist conformance) 0 1 2 3 4 ndition and functionality provides a public storm water quantity, storm water 0 1 2 3 4 or safe benefit. of Grading Plan Checklist deficiencies(e. ., design, function, access, etc.) 1 2 3 TOTAL SCORE Score 1 through 6:Not Acceptable for maintenance by the City unless corrected. Score> 7: Acceptable,continue to Step 3. �mments: STEP-3 Acceptability Criteria tore Field verification b the Cityconfirms the condition and functionality of the and 1 If this item receives a"0",the pond is Not Acceptable for maintenance by the City until corrected. If this item receives a"1", the pond is Acceptable for maintenance by the City once the following legal documents are executed: • Permanent Public Drainage or Drainage and Utility easement for the pond • Access Easement for the maintenance access corridor • Maintenance Agreement, with a hold harmless clause for site safety • Assessment Agreement Signature of Public Works Director Date • HAstorrawater\Residential Pond Transfer-Maintenance Policy.doc • � -� -F z � �x ,{ � O�PIIBLI� W KEY Subdivision: Blank=Not Applicable 0=Yes Submitted By: Date: x❑ =No Eng neer Reviewed By: Date: Engineer GENERAL ❑ Pond depth is 4 feet or greater. ❑El Plan is drawn in two-foot contours. ❑ Maximum pond depth based on normal water level is 10 Existing contours are dashed and proposed are solid. feet or less. ❑❑ All contours are labeled. ❑ Control outlet is provided to produce 48 hour drawdown Plan is 1`50'or larger scale. of hydraulic storage volume. ❑❑ North arrow shown(up or to left).' ❑ Control outlet is provided with skimmer to prevent Proposed elevations of garage floor,lowest opening and plugging from floating debris ground at front and rear of building,along with the ❑ Piped outlet is provided to accommodate a minimum of a structure type as indicated on plan. 10-year event. ❑❑ Property limits are shown. ❑ Emergency overflow spillway is provided to ❑ Existing public and private utilities are shown. accommodate 100-year event.High point elevation and Details of terrain and drainage are provided for areas direction of overflow are marked on plans. ❑ within 200' of the perimeter of the proposed grading. ❑ Emergency overflow spillway is located to protect ❑ Lot comer elevations are shown adjacent property and large fill sections. ❑ Control Elevations for drainage ways provided. ❑ 10:1 Bench is provided for first 1 foot of depth below Drainage directional arrows shown. Normal Water Elevation. ❑ Percent of grade is shown for streets and drainage swales. ❑ 4:1 max slope above normal water elevation. • ❑ Drainage flow away from structures. ❑ 3:1 max slope below normal water elevation ❑ Drainage flows over only one adjacent lot before proper ❑ 12'wide access and turn-around area for maintenance ❑ discharge vehicles is shown on a slope no greater than 15%. ❑ Park and wetland areas are shown ❑ Inlets at or below normal water level. ❑ Dedicated drainage easements provided ❑ Where possible,provide forebay just below inlet for ElAdjacent property protected from drainage and sediment. energy dissipation and settlement of coarse sediment. ❑ NPDES permit is included in grading specifications. ❑_20 scale grading plans with 1'contours of ponding areas Minimum lot grades are 2%wherever drainage from more are included. than one lot exists. ❑ Minimum lot grades are 1%wherever drainage from only one lot exists. DRAINAGE SWALES&EASEMENTS ❑ Drainage easements are shown on plan. ❑ The following areas are tabulated(in acres): ❑ Easement Documents are signed and submitted to Public • Total project area Works with a check for recording. • Total impervious surface area of project ❑ Velocity and shear stress computations are provided for • Total pervious area of project. drainage easements where concentrated flow from more • Total estimated impervious surface area of than 2 acre or 8 lots is directed. ultimate development ❑ Drainage easements are seeded and protected with wood • Total estimated pervious area of ultimate fiber blankets or they are sodded where concentrated flow development from more than 1 acre or 4 lots is directed. ❑ Drainage easements are provided where concentrated flow PERMAr4'ENT PONDS from more than 1 adjacent lot is received. ❑ Public pond areas are platted as outlots,Private pond ❑ Permanent turf reinforcement mats are installed in areas are platted as drainage easements. drainage easements where velocities exceed 7 ft/sec. ❑ The following areas are tabulated(in cubic feet): ❑ Minimum drainage easements for flows from l acre or • Dead sediment storage volume required. less or 4 lots or less shall be'a minimum of 15, wide. • Dead sediment storage area provided. Ditch shall be 1.9'deep V-shaped with 4:1 slopes up to • Hydraulic storage volume required: easement line. • Hydraulic storage volume provided: ❑ Minimum drainage easements for flows from more than 1 • El Normal water elevation is shown. acre or more than 4 lots shall be a minimum of 20'wide. ❑ 100 year high water level is shown. Ditch shall be a minimum of 2' deep with a 4'bottom and ❑ Length to width ratio of pond is 3 or greater. 4:1 slopes up to easement line. ElInlet(s)and outlet are located at opposite ends to prevent ❑ Minimum slope of drainage swales is 2%. short circuiting of pond. STORM DRAIN SYSTEM ❑ 400'max.manhole spacing for lines 15"diameter or less. STEEP SLOPES ❑ 500'max.manhole spacing for lines 18"to 30"diameter. ❑ Disturbed slopes in excess of 4:1 are seeded and protected • ❑ Overflow swales are provided which limit depth of with wood fiber blankets or they are sodded and staked. ponding in street to 3' or less. ❑ Diversion swales are used at top of slopes exceeding 4:1 ❑ Emergency overflow along with the high point elevation and direct flow to protected outfall(turf mat,pipe,rip- and direction of overflow are marked on plans. rap) ❑ Emergency overflow swale meets minimum drainage easement standards noted above SILT FENCE ❑ CB's spaced 600'Max.on collector and arterial streets. ❑ Silt fences are provided to protect adjacent property from ❑ CB's spaced 1000'Max.on residential streets. receiving untreated runoff. ❑ Drainage does not cross intersections(no valley gutters). ❑ Water bodies and watercourses are protected from ❑ Swale drainage is picked up in CB before crossing walk. receiving untreated runoff. INLETS,OUTLETS&ENERGY DISSIPATION ❑ Silt fences follow contour lines with ends flared uphill to ❑ Discharge direction of flow shall be at 45 degrees or less provide storage capacity. to the flow direction of receiving ditch or stream. ❑ Silt fences are used in sheet flow areas only,not for ❑ Discharge shall be taken to rear property lines at a concentrated flows. minimum. ❑ Flow length up slope from silt fence shall is limited as ElWhere discharge velocities are not greater than 4 fps,rip- follows: rap and filter are provided in accordance with MnDOT 0 400'max for slopes less than 3%. Standard Plate No.3133 and 3134. 0 200'max.for slopes 3%to 6%. ❑ Where discharge velocities are greater than 4 fps, energy 0 100'max.for slopes greater than 6%. dissipater is provided to reduce velocity to 8 fps or less. Unless velocity is reduced below 6 fps,rip-rap is required STABILIZED VEHICLE EXITS in conjunction with energy dissipater. ❑ Stabilized Vehicle Exits are provided where construction ❑ Discharges on slopes steeper than 2%shall not be allowed equipment will exit site. unless discharge is into existing drainage ditch and volume of water in ditch is not greater than 110%of the TEMPORARY SEDIMENTATION TRAPS pre developed condition. ❑ Used for drainage area 5 acres or less. El Trash racks on inlet structures shall be designed assuming ❑ Piped outlet is capable of handling a 10-year storm. a minimum of 50%plugging condition. • ❑ Gravel outlets provide 4 feet of width per acre in drainage ❑ Rip Rap and filters are designed in accordance with area and are located at low point of embankment. MnDOT standards and volumes at each outlet are shown ❑ Gravel used for outlets should be 1"to 2"size. on plan. ❑ Top of gravel outlets is P below top of embankment. DIVERSION SWALES ❑ Temporary pond sized to retain 1.5"of rainfall from entire site. ❑ Diversion swales,slope drains or turf reinforcement mats ❑ Pond is fenced if slopes exceed 4:1 are provided for concentrated flows on the following slopes: TEMPORARY SEDIMENT PONDS • Slopes 6-12%longer than 100 feet. ❑ Temporary sediment pond is provided for drainage areas • Slopes greater than 12%Ionger than 50 feet. larger than 5 acres flowing to a single point. El Swale grades in excess of 2%shall be stabilized. ❑ Temporary pond sized to retain 1.5"of rainfall from entire ❑ Last 20 f et of diversion Swale is at 1%or less. site. ❑ A level spreader is utilized to distribute water and prevent ❑ Pond is fenced if slope's exceed 4:1 concentrated flows at end of diversion swale. ❑ Riser pipe per Rochester Standard Details is provided. ❑GROUND COVER Emergency Overflow is provided. ❑ Plan or Specification indicates placement and type of temporary cover. COMMENTS: i CITY OF ROCHESTER,MINNESOTA • DEPARTMENT OF PUBLIC WORKS GRADING PLAN CHECKLIST revised August 5, 1998 KEG' Subdivision: Blank=Not Applicable ❑✓ =Yes Submitted By: Date: No Engineer Reviewed By: Date: Engineer GENERAL ❑ Inlet(s)and outlet are located at opposite ends to prevent ❑ Plan is drawn in two-foot contours. short circuiting of pond. El Existing contours are dashed and proposed are solid. El Pond depth is 4 to 10 feet based on normal water level. ❑ All contours are labeled. ❑ Outlet is designed to discharge"hydraulic storage ❑ Plan is 1"=50'or larger scale, volume"per NPDES particle removal requirements. ❑ North arrow shown. ❑ Control outlet is designed to prevent discharge of debris ❑ Proposed elevations of garage and lowest floor,lowest or plugging from floating debris opening and ground at front and rear of building,along ❑ Piped outlet accommodates a minimum 10-year event. with the structure type are indicated on plan. ❑ Emergency overflow spillway is provided to ❑ Adequate freeboard to structures. Floor or opening accommodate 100-year event.High point elevation and minimum 1'above any overflow elevation,and minimum direction of overflow are marked on plans. 2' above pond 100-year water level,whichever is greater. ❑ Emergency overflow spillway is located to protect ❑ Property limits are shown. Lot&block info.shown. adjacent property and large fill sections. ❑ Existing public and private utilities are shown. ❑ 10:1 bench is provided for first 1 foot of depth below ❑ Details of terrain and drainage are provided for arers normal water elevation. adjacent to the proposed grading. ❑ 4:1 max slope from normal water elevation to 100-year ❑ Lot comer elevations are shown. water elevation. ❑ Control elevations for drainage ways provided. ❑ 3:1 max slope below normal water elevation ❑ Drainage directional arrows shown. ❑ 12'wide access and turn-around area for maintenance ElPercent of slope is shown for streets and drainage swales. vehicles is shown on a slope< 15%,cross slope<6%. ❑ Drainage flows away from structures. ❑ Inlets at or below norinal water level. ❑ Park and wetland areas are shown. ❑ Where possible,provide forebay at the inlet. ❑ Dedicated drainage easements provided. ❑ 50 scale grading plan with pond cross section. ❑ Adjacent property protected from drainage and sediment. El100-year runoff which is designed to flow to the pond ❑ NPDES permit is included in grading specifications. does not bypass the pond;unmodeled 100-year flow does ❑ Minimum lot grades are 2%wherever drainage from more not enter the pond. than one lot exists. ❑ Minimum lot grades are 1%wherever drainage from only DRAINAGE SWALES& EASEMENTS ❑ one lot exists.The following areas are tabulated(in acres): El Drainage easements are provided where concentrated flow is received from more than I adjacent lot and also where • Total project area. concentrated flow is received from more than 1 acre of • Total impervious surface area of project. adjacent property. • Total pervious area of project. ❑ Drainage easements are shown on the plan. • Total estimated impervious surface area of ❑ Easement documents are signed and submitted to Public ultimate development. Works with a check for recording. • Total estimated pervious area of ultimate ❑ Silt fence along the perimeter of drainage easements. development. ❑ Velocity computations are provided for drainage easements where concentrated flow from more than 2 PERMANENT PONDS acres or 8 lots is directed. ❑ Public pond areas are platted as outlots,private pond ❑ Drainage easements are seeded and protected with erosion areas are platted as drainage easements. control blankets or they are sodded where concentrated ❑ The following areas are tabulated(in cubic feet): flow from more than 1 acre or 4 lots is directed. Blanket • Dead sediment storage volume required. category per Mn/DOT 3885.1. • Dead sediment storage area provided. ❑ Where 10-year velocities in drainage easements exceed 5 • Hydraulic storage volume required. ft/sec,permanent turf reinforcement mats are installed per • Hydraulic storage volume provided. City std.plate 7-07. Plans specify manufacturer and El Norm al water elevation is shown. product. ❑ 100-year high water level is shown. ❑ Length to width ratio of pond is 3 or greater. ❑ Minimum drainage easements for flows from 1 acre or ❑ Diversion swales,slope drains or turf reinforcement mats less or 4 lots or less shall be a minimum of 15,wide. are provided for concentrated flows on the following • Ditch shall be 1.9' deep V-shaped with 4:1 slopes up to slopes: easement line. 0 Slopes 6-12%longer than 100 feet. ❑ Minimum drainage easements for flows from more than 1 0 Slopes greater than 12%longer than 50 feet. acre or more than 4 lots shall be a minimum of 20'wide. ❑ Swale grades in excess of 2%shall be stabilized. Ditch shall be a minimum of 2' deep with a 4'bottom and ❑ Last 20 feet of diversion swale is at 1%or Iess. 4:1 slopes up to easement Iine. ❑ A level spreader is utilized to distribute water and prevent ❑ Minimum slope of small drainage swales is 2% concentrated flows at end of diversion Swale. STORM DRAIN SYSTEM STEEP SLOPES ❑ 400'max.manhole spacing for lines 15"diameter or less. El Disturbed slopes in excess of 3:1 and slopes longer than ❑ 500'max.manhole spacing for lines 18"to 30"diameter. 30'in excess of 4:1 are seeded and protected with erosion ❑ Overflow swales are provided which limit depth of control blankets or they are sodded and staked. Blanket ponding in street to 2' or less. category per Mn/DOT 3885.1. ❑ Emergency overflow with the high point elevation and ❑ Diversion swales are used at top of slopes exceeding 4:1 direction of overflow are marked on plans. to direct flow to protected outfall(turf mat,pipe,riprap) ❑ Emergency overflow Swale meets minimum drainage easement standards noted above. SILT FENCE ❑ CB's spaced 600'max.on collector and arterial streets. ❑ Silt fences are provided to protect adjacent property from ❑ CB's spaced 1000'max.on residential streets. receiving untreated runoff. ❑ Storm sewer does not flow through CB's. ❑ Water bodies and watercourses are protected from ❑ Drainage does not cross intersections(no valley gutters). receiving untreated runoff. El Swale drainage is picked up in CB before crossing walk. ❑ Silt fences follow contour lines with ends flared uphill to provide storage capacity. INLETS,OUTLETS&ENERGY DISSIPATION ❑ Silt fences are used in sheet flow areas only,not for ❑ Discharge direction of flow shall be at 45 degrees or less concentrated flows. to the flow direction of receiving ditch or stream. ❑ Flow length up slope from silt fence shall is Iimited as ❑ Discharge shall be taken to rear property lines at a follows: ❑ mum' 400'max for slopes less than 3%. Where discharge pipe velocities are 10 fps or less,riprap 200'max.for slopes 3%to 6%. and filter are provided in accordance with Mn/DOT 100'max.for slopes greater than 6%. Standard Plate No.3133 or 3134. ❑ Where discharge pipe velocities are greater than 10 fps, STABILIZED VEHICLE EXITS energy dissipater is provided along with riprap and filter. ❑ Stabilized vehicle exits are provided where construction ❑ }tiprap and filters are designed per Mn/DOT standards equipment will exit site. and volumes at each outlet are shown on plan. ❑ Discharges on slopes steeper than 2%shall not be allowed TEMPORARY SEDIMENTATION BASINS unless discharge is into existing drainage ditch and volume of water in ditch is not greater than 110%of the ❑ Sized to detain 0.5', of runoff from the drainage area before discharge across gravel outlet or top of riser pipe. pre-developed condition. ❑ Fenced if slopes exceed 4:1. ❑ Trash racks on inlet structures shall be designed assuming ❑ For drainage areas 5 acres or less,outlet may be per City a minimum of 50%plugging condition. Standard Plate 7-05 or alternate design. Protected outlet GROUND COVER is adequate for a 10-year storm. ElFor drainage areas greater than 5 acres,riser pipe ❑ Plan or Specification indicates placement and type of adequate for a 10-year storm is provided. Emergency temporary cover. overflow is provided for 50-year storm. DIVERSION SWALES COMMENTS: i CITY OF ROCHESTER,MINNESOTA DEPARTMENT OF PUBLIC WORKS GRADING PLAN CHECKLIST revised April 8, 1999 KEG' Site: Blank=Not Applicable ❑✓ =Yes Submitted By: bate: _No Enginccr Reviewed By: Date: Engincr 711®R.l�A+7 r+ai GENERAL ❑ Plan is 1"=50' or larger scale. North arrow shown. PERMANENT PONDS ❑❑ Name and address of the owner are shown. ❑ Ponds serving less than 50 acres and not identified as ❑ Plan is drawn in two-foot contours. Contours are labeled. regional ponds shall be privately owned and maintained. ❑ Existing contours are dashed and proposed are solid. ❑ Pond areas are generally platted as outlots. A pond that Property Iimits are shown. Lot&block information will serve only the lot on which it is located should simply shown if platted. Street address shown if unplatted. be a drainage easement on that lot. ❑ Details of terrain and drainage are provided for areas ❑ Normal water elevation is shown. adjacent to the proposed grading. ❑ 100- ear high �h water level is shown. ❑❑ Existing public and private utilities are shown. ❑. Inlet(s)and outlet are located at opposite ends of pond ❑ Wetland areas are shown and protected. and length to width ratio>3 where practical. ❑ Proposed walk is shown for commercial/industrial sites. ❑ Pond depth is 4 to 10 feet based on normal water level. ❑ Proposed lot corner elevations are shown. ❑ Outlet is designed to meet NPDES particle removal Proposed elevations of garage and lowest floor,ground at requirements. front and rear of building,along with the structure type ❑ Outlet is designed to prevent short circuiting and are indicated on plan. discharge of floating debris. ❑ For each residential lot,elevation difference from ElPiped outlet accommodates a minimum 10-year event. • benchmark(such as top of curb at property Iine)to lowest ❑ Emergency overflow spillway is provided to floor elevation is provided. Plan indicates which lots are accommodate 100-year event.High point elevation and critical and will require field verification. direction of overflow are marked on plans. ❑ Adequate freeboard to structures. Floor or opening ❑ Emergency overflow spillway is located to protect minimum 1'above any overflow elevation,and minimum adjacent property and large fill sections. ❑ 2'above pond 100-year water level,whichever is greater. ❑ 10:1 bench is provided for first I foot of depth below Control elevations for drainage ways provided. normal water elevation. El❑ Drainage directional arrows shown. El4:1 max slope from normal water elevation to 100-year Percent of slope is shown for streets and drainage swales. water elevation. ❑❑ Drainage flows away from structures. ❑ 3:1 max slope below normal water elevation ❑ Adjacent property protected from drainage and sediment. ❑ 12'wide access and turn-around area for maintenance Minimum lot grades are 2%wherever drainage from more vehicles is shown on a slope S 15%,cross slope S 6%. ❑ than one lot exists. ❑ Inlets at or below normal water level. Minimum lot grades are 1%wherever drainage from only ❑ Where possible,provide forebay at the inlet. one Iot exists. ❑ 50 scale grading plan with pond cross section. ❑ Fill&cut setbacks which are>2'(per UDC ❑ 100-year runoff which is designed to flow to the pond ❑ requirements)are dimensioned on the plans. does not bypass the pond;unmodeled 100-year flow does Stabilized vehicle exits are provided where construction not enter the pond. ❑ equipment will exit site. ❑ For public ponds,seed mix MII/DOT 25A for a 10' Temporary or permanent cover is indicated for all perimeter around the pond. Seed mix Mn/DOT 15A for disturbed areas. Temporary seeding specifies seed mix; remainder of the pond outlot. includes mulch on all slopes longer than 200' and all slopes>5%. Permanent cover specifies topsoil,seed mix DRAINAGE SWALES&EASEMENTS ❑ and mulch,or topsoil and sod. ❑ Drainage easements are provided where concentrated flow For sites where temporary or permanent cover will not be is received from more than I adjacent lot and also where complete by November 15,plan indicates adequate concentrated flow is received from more than 1 acre of measures to control spring erosion&sedimentation. adjacent property. ❑ The following areas are tabulated(in acres): ❑ Drainage easements are shown and labeled on the plan. • Total project area and total impervious and ❑ Easement documents are signed and submitted to Public Pervious surface areas of project. Works with a check for recording. • Total estimated impervious and pervious surface ❑ Velocity computations are provided for drainage areas of ultimate development. easements where concentrated flow from more than 2 ❑ XPDES permit(if applicable)is referred to on the plan. acres or 8 lots is directed. ❑ Drainage easements are seeded and protected with erosion ❑ Where discharge pipe velocities are 10 fps or less,riprap control blankets or they are sodded where concentrated and filter volumes are indicated in accordance with flow from more than 1 acre or 4 lots is directed. Blanket Mn/DOT Standard Plate No.3133 or 3134. category specified per Mn/DOT 3885.1. Plan depicts ❑ Where discharge pipe velocities are greater than 10 fps, required blanket locations. energy dissipater is provided along with riprap and filter. ❑ Where I0-year velocities in drainage easements exceed 5 ElDischarges on slopes steeper than 2%shall not be allowed ft/sec,permanent turf reinforcement mats are installed per unless discharge is into existing drainage ditch and City std.plate 7-07.Blanket per Mn/DOT 3888.2A2 or volume of water in ditch is not greater than 110%of the manufacturer and product is specified. Plan depicts pre-developed condition. blanket locations and cross sections. ElTrash racks on inlet structures in wooded areas shall be ❑ Minimum drainage easements for flows from 1 acre or designed assuming a minimum of 50%plugging less or 4 lots or less shall be a minimum of 15'wide. condition. Ditch shall be 1.9' deep V-shaped with 4:1 slopes up to easement line. STEEP SLOPES ❑ Minimum drainage easements for flows from more than I ❑ Disturbed slopes in excess of 3:1 and slopes longer than acre or more than 4 lots shall be a minimum of 20'wide. 30'in excess of 4:1 are seeded and protected with erosion Ditch shall be a minimum of 2' deep with a 4'bottom and control blankets or they are sodded and staked. Blanket 4:1 slopes up to easement line. category specified per Mn/DOT 3885.1. Plan depicts ❑ Minimum slope of small drainage swales is 2%. required blanket locations. ❑ Diversion swales are used at top of slopes exceeding 4:1 STORM DRAIN SYSTEM to direct flow to protected outfall(turf mat,pipe,riprap) ❑ 400'max,manhole spacing for lines 15"diameter or less. ❑ Diversion swales,slope drains or turf reinforcement mats ❑ 500'max.manhole spacing for lines 18"to 30"diameter. are provided for concentrated flows on the following ❑ Overflow swales are provided which limit depth of slopes: ponding in street to 2' or less. Slopes 6-12%longer than 100 feet. ❑ Emergency overflow with the high point elevation and Slopes greater than 12%longer than 50 feet. direction of overflow are marked on plans. ❑ Emergency overflow swale meets minimum drainage SILT FENCE easement standards noted above. ❑ Silt fences are provided to protect adjacent property from ❑ CB's spaced 600'max.on collector and arterial streets. receiving untreated runoff. ❑ CB's spaced 1000 max.on residential streets. ❑ Water bodies and watercourses are protected from ❑ Apron inlets to the storm sewer include trash racks. receiving untreated runoff. ❑ Drainage from subdrains,sump pumps,and building ❑ Silt fences follow contour lines with ends flared uphill to storm drains does not flow through public CB's. provide storage capacity. ❑ Drainage does not cross intersections(no valley gutters). ❑ Silt fences are used in sheet flow areas only,not for ❑ Not more than 3 CB's in a series(at an intersection) concentrated flows. before connecting to the storm sewer main. ❑ Flow length up slope from silt fence is limited as follows: ❑ Storm sewer main generally does not flow through CB's. & 400'max for slopes less than 3%. ❑ Flow direction change is:5 90°at junctions. . 200'max.for slopes 3%to 6%. ❑ Swale drainage is picked up in CB before crossing walk. & 100'max.for slopes greater than 6%. ❑ All apron elevations(inlets and outlets)are labeled. Area inlet elevations are labeled. Pipe sizes are labeled. TEMPORARY SEDIMENTATION BASINS INLETS,OUTLETS&ENERGY DISSIPATION ❑ Sized to detain 0.5"of runoff from the drainage area before discharge across gravel outlet or top of riser pipe. ❑ Discharge direction of flow shall be at 45 degrees or less ❑ Fenced if slopes exceed 4:1. to the flow direction of receiving ditch or stream. ❑ Principal and emergency spillway designed per BMP ❑ Discharges to rear property lines shall generally be piped storm frequency standards. For drainage areas 5 acres or tout least the rear property line, less,outlet per City Standard Plate 7-05 may be used. COMMENTS: • 41Y�-y CITY OF ROCHESTER,MIN'NESOTA DEPARTMENT.OF PUBLIC WORKS GRADING PLANT CHECKLIST revised May 2000 KEY � D=Yes Site: 7 =No Submitted By: Date: Blank=Not Applicable ReF iewed By: Date: GENERAL follow contour lines with ends flared uphill to provide B Completed grading permit application submitted to Public storage capacity.If silt fence is used in concentrated flow Works with the grading plan. areas it is"heavy duty"type. Final plan is signed by a registered professional. B Temporary or permanent cover is indicated for all disturbe PIan is 1"=50'or larger scale. North arrow shown. areas. Temporary seeding specifies seed mix and includes Name and address of the owner are shown, disk anchored mulch on all slopes longer than 200'or > Property limits are shown. Streets are labeled.Lot&block 5%. Permanent cover specifies topsoil,seed mix and disk information shown if platted. Street address shown if anchored mulch,or topsoil and sod. unplatted. As a minimum,disturbed slopes in excess of 3:1 and slope d Plan is drawn in two-foot contours. All finished contours longer than 30'in excess of 4:1 are seeded and protected and adequate existing contours are labeled. with erosion control blankets or they are sodded and staked Existing contours are dashed and proposed are solid. Blanket category specified per Mn/DOT 3885.1. Plan Directional arrows are shown for proposed drainage. depicts required blanket locations. z-� Details of terrain and drainage are provided for areas 11;� Temporary or permanent diversion swales to a protected adjacent to the proposed grading. outfall(turf mat,pipe,riprap)are used at the top of slopes � Existing public and private utilities are shown. exceeding 4:1 when applicable. � Wetland areas are shown and protected. 1�p For sites where temporary or permanent cover will not be d All proposed lot corer elevations are shown. complete by November 15,plan indicates adequate B Proposed elevations of garage and lowest floor,ground at measures to control spring erosion&sedimentation. • front and rear of building,along with the structure type are indicated on the plan. TEMPORARY SEDIMENTATION BASIN'S B Untreated wood construction is min.6"from the ground. B Must be provided if>_.10 disturbed acres discharge at a B Adequate freeboard to structures. Floor el. or the grade discernable point.Otherwise highly recommended. adjacent to the building is at least P above any overflow z� Sized to detain 0.5"of runoff from the drainage area, elevation,and at least 2' above any pond 100-year water Principal and emergency spillway designed per BMP storm level,whichever is greater.Min. 1'above FEMA flood el. frequency standards. B Drainage flows away from structures. B Fenced if slopes exceed 4:1. B Minimum lot slopes for vegetated areas are 2%preferred,' � Plan requires any permanent or temporary sediment ponds 1%absolute minimum to be constructed at the beginning of construction. Percent of slope is shown for streets and drainage swales. B Proposed walk is shown for commercial/industrial sites. PERMANENT PONDS z�p Fill&cut setbacks which are>2'(per a Ponds serving less than 50 developable acres and not (p UBC appendix identified as regional ponds shall be privately owned and chapter 33)are dimensioned on the plans(where perimeter cut slope ht.is> 10' or fill slope ht.is>4'). maintained. ,:�Ip County or Mn/DOT permit obtained for work their ROW. B Pond areas are generally pIatted.as outlots. A pond that wi ,!�R Substantial Land Alteration approved for elevation changes serve only the lot on which it is located should simply be a z 10' or other criteria that require a SLA. drainage easement on that lot. Any City Council approval conditions are met. 50 scale or larger grading plan with pond cross section. 4',�p Storm water management(if required)is addressed. ,'p Where possible,provide a forebay at.the inlet;locate inlet The following areas are tabulated(in acres): and outlet at opposite ends of pond;and provide length to • Total project area and total impervious and pervious width ratio>3. surface areas of project. Multi-cell design where practical. • Total estimated impervious and � 10:1 bench is provided for first 1 foot of depth below p pervious surface areas normal water elevation. of ultimate development. 4:1 max slope from normal water elevation to 100-year EROSION CONTROL&TURF ESTABLISHMENT water elevation. • B NPDES permit(if applicable)is referred to on the plan. B 3:1 max slope below normal water elevation. B Adjacent property protected from drainage and sediment. Pond depth is 4 to 10 feet based on normal water level. Stabilized vehicle exit(s)are provided. � Normal water elevation is shown. B Silt fences are provided to protect adjacent property and 100-year high water level is shown. water bodies from receiving untreated runoff. Silt fences Inlets are at or below normal water level. 44�7 Outlet is designed to prevent short circuiting and discharge 0*7 of floating debris, and is designed to meet NPDES article of documents are signed and submitted to Public removal requirements. p Works with a check for recording if not included in plat. Piped outlet accommodates a minimtvr110-yt:., T STORM DRAIN SYSTEM,INLETS,&OVERFLOWS Emergency overflow spillway is provided to accommodate B All apron elevations(inlets and outlets)are labeled. Area 100-year event.High point elevation and direction of inlet elevations are labeled. Pipe sizes are labeled. overflow are marked on plans. B Emergency overflow spillway is located to rotect adj B 400'max.manhole spacing for lines 15"diameter or less. acent property and large fill sections. p 1 B 500'max.manhole spacing for lines 18"to 30"diameter. 100-year runoff which is designed to flow to the and does B Drainage from subdrains,sump pumps,and building storm not bypass the pond;unmodeled 100-year flow does not drains does not flow through public CB Is. enter the pond. d Not more than 3 CB's in a series(at an intersection)before B Minimum 10'width at top of dam(if dam is<15'high). connecting to the storm sewer main. Storm sewer main generally does not flow through CB's. B 12'wide access and turn-around area for maintenance vehicles is shown on a slo e< o o � Flow direction change is 5 901 at junctions. p 1515 cross slope 5 6 ft Drainage does not cross intersections(no valley gutters). d Pond access is included in a min. 15'wide portion of the pond outlot If access is in an easement across private B CB spacing as necessary for inlet capacity,arfd not property, a 12'wide paved access road is provided. exceeding 1000, on residential streets or 600' on collector For public ponds,seed mix Mn/DOT 25A for a 10' and arterial streets. perimeter around the pond. Seed mix Mn/DOT 15A for the B Apron inlets to the storm sewer include trash racks. remainder of the pond outlot. Trash racks on inlet structures in wooded areas designed B DNR dam safety permit obtained if dam height is>6' and assuming a mrnimum of 50%plugging condition. storage to top of dam is> 15 acre-ft. Drainage from off street parking is collected on-site and no sheet drained onto sidewalks or adjacent property. DRAINAGE SWALES&EASEMENTS Swale drainage is collected in CB before crossing walk. R Drainage easements are provided where concentrated flow 4�'p Overflow swales are provided which limit the depth of is received from more than 1 adjacent lot and also where ponding in the street to 2'or less. concentrated flow is received from more than 1 acre of B Emergency overflow with the high point elevation and adjacent property. direction of overflow are marked on plans. ,�Op Drainage easements are shown and labeled on the plan. B Emergency overflow swale meets minimum drainage • ,::�9 Minimum drainage easements for flows from 1 acre or less easement standards noted above. or 4 lots or less are a minimum of 15'wide. Ditch is 1.9' deep V-shaped with 4:1 slopes.. OUTLETS&ENERGY DISSIPATION Minimum drainage easements for flows from more than I Discharge direction of flow generally 45 degrees or less to acre or more than 4 Iots are a minimum of 20'wide. Ditch the flow direction of receiving ditch or stream. is a minimum of 2' deep with a 4'bottom and 4:1 slopes up d Discharges to rear property lines shall generally be piped to to the easement line. at least the rear property line. Control elevations for drainage ways are.provided. B Where discharge pipe velocities are 10 fps or Iess,riprap Minimum slope of small drainage swales is 2%, and filter volumes are indicated in accordance with Drainage easements are seeded and protected with erosion Mn/DOT Standard Plate No.3133 or 3134. � Where discharge pipe velocities are greater than 10 fps, control blankets or they are sodded where concentrated flow from more than 1 acre or 4 lots is directed. Blanket energy dissipater is provided along with riprap and filter. category specified per Mn/DOT 3885.1. Plan depicts B Discharges on slopes steeper than 2%shall not be allowed required blanket locations. unless discharge is into existing drainage ditch and volume Velocity computations are provided for drainage easements of water in ditch is not greater than 110%of the pre- where concentrated flow from more than 2 acres or 8 lots is developed condition. directed.Where 10-year velocities exceed 5 ft/sec, permanent turf reinforcement mats are installed per City std.plate 7-05.Blanket per Mn/DOT 3888.2A2 or COMMENTS: