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HomeMy WebLinkAboutAgreement & Plan_790 Meadows 610 620 Gillespie_0033,0034.2020.BCOMSTORMWATER BEST MANAGEMENT PRACTICES OPERATIONS AND MAINTENANCE AGREEMENT City of Aspen, Colorado THIS AGREEMENT, made and entered into this R�y of & .44021, by and between The Aspen Institute, Inc., hereinafter called the "Landowner", the Music Association of Aspen, Inc., hereinafter called the "Adjacent Party" and the City of Aspen, Colorado, hereinafter called the "City". WITNESSETH WHEREAS, the Landowner is the owner of certain real property described as Aspen Meadows Subdivision, Lot 1B, Parcel Nu. 273512129809, located at 620 Gillespie Avenue, hereinafter called the "Property", and the Adjacent Party is the owner of certain real property, described as Aspen Meadows Subdivision, Lot 2, Parcel Nu. 273512129802, immediately contiguous to the Landowner's property as indicated on Exhibit A, hereinafter called the "Adjacent Property," attached hereto and made a part hereof, and WHEREAS, the Landowner is proceeding to build on and develop the Property and the Adjacent Party is aware and supportive of the development of the Property and the location of the stormwater management facilities and rain gardens; and WHEREAS, the stormwater management BMP Operations and Maintenance Plan for the properties identified herein has been approved by the City, herein after called the "Plan", which is attached hereto as Exhibit B and made part hereof, as approved by the City, provides for the management of stormwater within the confines of the Properties through the use of stormwater management or Best Management Practices (BMPs) facilities; and WHEREAS, the City, the Landowner and the Adjacent Party, and their successors and assigns, agrees that the health, safety, and welfare of the residents of the City of Aspen, Colorado, and the maintenance of water quality require that on -site stormwater management /BMP facilities be constructed and maintained on the Property and the Adjacent Property; and WHEREAS, the City requires, through implementation of the Plan from the Landowners attached hereto as Exhibit B, that on -site stormwater management/BMP as shown on the Plan be adequately constructed, operated, and maintained by the Landowner, its successors and assigns. NOW THEREFORE, in consideration of the foregoing premises, the mutual covenants contained herein, and the following terms and conditions, the parties hereto agree as follows: 1. Construction of BMP facilities by Landowner. The on -site stormwater management/BMP facilities shall be constructed by the Landowner, its successors and assigns, in accordance with the plans and specifications approved by the City and identified in the Plan. IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIII II I III IIIIIIIIII IIIII IIII IIIII Illl RECEPTION#: 694685, R: $63.00, D: $0.00 DOC CODE: AGREEMENT Pg 1 of 11, 05/02/2023 at 02:01:50 PM Ingrid K. Grueter, Pitkin County, CO 2. Duty of Operation and Maintenance of Facility. The Landowner, its successors and assigns, including any homeowners' association, shall adequately operate, inspect, and maintain the stormwater management /BMP facilities as acceptable to the City and in accordance with the specific operations, inspections, and maintenance requirements noted in the Plan. Adequate operation and maintenance is herein defined as good working conditions so that these facilities are performing their design function. The Adjacent Party is not responsible for the operation, inspection or maintenance of the stormwater management/BMP facilities on its property, but hereby agrees to cooperate with the Landowner and the City with regard to Landowner's operation, inspection and maintenance of these stormwater management/BMP facilities. For the sake of clarity and the avoidance of doubt, the rain gardens located on Adjacent Property are solely for the stormwater drainage associated with the improvements on the Adjacent Property and these rain gardens shall not handle any stormwater drainage from the Landowner's Property. If, at some future time, Adjacent Party redevelops Adjacent Property and such redevelopment requires the relocation of rain gardens and/or stormwater management/BMP facilities, subject to approval by the City, Adjacent Party shall be solely responsible for the cost of such relocation and accompanying costs. 3. Duty of Documentation. The Landowner, its successors and assigns, shall document inspections, maintenance, and repairs performed and provides said documentation to the City or its representative upon request. 4. Right of Entry on Property. The Landowner and the Adjacent Party, along with their successors, and assigns, hereby grant permission to the City, its authorized agents and employees, to enter upon the Property at reasonable times and upon presentation of proper identification, and to inspect the stormwater management/BMP facilities whenever the City deems necessary. The purpose of inspection is to follow-up on suspected or reported deficiencies, to respond to citizen complaints, and/or to assure safe and proper functioning of the facilities. The City shall provide the Landowner, its successors and assigns, copies of the inspection findings and a directive with timelines to commence with the repairs if necessary. 5. Failure to Maintain. In the event the Landowner, its successors and assigns, fails to construct, operate and maintain the stormwater management/BMP facilities in good working conditions acceptable to the City, the City, its authorized agents and employees, may enter upon the Property and take whatever action(s) deemed necessary to correct deficiencies identified in the inspection report and to charge the costs of such construction or repairs to the Landowner. It is expressly understood and agreed that the City is under no obligation to install, construct, or routinely maintain or repair said stormwater management/BMP facilities, and in no event shall this Agreement be constructed to impose any such obligation on the City. 6. Reimbursement by Landowner. In the event the City pursuant to this Agreement, performs work of any nature, or expends any funds in performance of said work for labor, use of equipment, supplies, materials, and the like, the Landowner, its successors or assigns, shall reimburse the City upon demand, within thirty (30) days of receipt thereof for all actual costs incurred by the City hereunder. 2 7. Duty to Inspect by City. The City, its employees or representatives, shall inspect the stormwater management/BMP facilities at a minimum of once every three years to ensure their continued and adequate functioning. 8. Release of City. The Landowner and the Adjacent Party, along with their executors, administrators, assigns, and other successors in interests, shall release the City, its employees and designated representatives from all damages, accidents, casualties, occurrences, or claims which might arise or be asserted against said City, employees, and representatives from the construction, presence, existence, operative or maintenance of the stormwater management/BMP facilities by the Landowner or City. In the event that a claim is asserted against the City, its elected officials, City Officers or employees, the City shall promptly notify the Landowner and the Landowner shall defend, at its own expense, any suit based on the claim. If any judgement or claim against the City's employees or designated representative shall be allowed, the Landowner shall pay all cost and expenses regarding said judgment or claim. 9. Recording of Agreement running with the Property. This Agreement shall be recorded in the real property records of Pitkin County, Colorado, and shall constitute running with the Property or land, and shall be binding on the Landowner, it administrators, executors, assigns, heirs and any other successors in interests, in perpetuity. IN WITNESS WHEREOF the undersigned have hereunto affixed their signatures as of the date first above written. LANDOWNER: V/By: Print Name: Richard Stettner As: The Aspen Institute, Vice President of Aspen Campus Facilities & Operations State of Colorado) :ss County of Pitkin) The foregoing Agreement was acknowledged before nie this day of bor, , 2021, by Richard Stettner as Vice President of Aspen Campus Facilities & Operations. KATHERINE SEWARD NOTARY PUBLIC J51 STATE OF COLORADO G NOTARY ID 2018401306 'rt'r MY COMMISSION EXPIRES MARCH 26. 2= otary Public My Commission Expires: -61 ?A- ra . 3 a ADJAC)I:. By: Print Name: As: s:+7favo 11&e- 4s' o4eri-7 ���>�Q?►- State of ) :ss DANIEL BENAVENT WILLIAMS NOTARY PUBLIC STATE OF COLORADO County of V7) NOTARY ID 20214038733 W COMMISSION EXPIRES SEPTEAM48ERA 2025 The Vegoin greement as knowledge before me is day of , 20� by r s i Notary Public My Commission Expires: °i .3 THE CITY OF ASPEN: By: -- �/1 Print Name ��� As: LORENA VARGAS State of Colorado ) :ss NOTARY PUBUC STATE OF COLORADO of Pitkin Notary ID 20174MIBO County ) MY Caavwicn EVkW July 12, 2026 The foregoing Agreement as acknowledged before me this 2-7 by T YISVj AratA on as day of Jax)- , 20223 otary Public My Commission Expires: j kl12-202(0 4 I-OwRn Ow htk/,rf FfiCw &02 pout ow#w� CIVERFIO:, .4Sr,-PY- AAT7fAV4; -- AM,') S-WALF A) HNTOWIC PA ro FRAPS RAIN GARDEN ANIFS 3--,\. A& -SA144 i To MORN 0.-- R- j tax RA'N GARDEN Al PROPM,ry :SAC aFrWUN ASPCN-1 WS77TUX PROPMY AAA ASPEN LOW ?Ts'n'PAZ PROPERnY, ---------- A ' f,�- RAIN GARDEN AMFS 1 6-.I-qm &I DEWN R4W CARM-Al- (,eW fWAALEW AREA )#""* I f'CV,T or fYkOvo C-rPN A0 P� J A'ftl Or S4WYGPWrE4 6GOW) NO 4,VSCiRN4&-;' F� 0 w ROO W, APPAWJVr SNJTF FLOW AORPIWARD Exhibit B Prepared by Max Essenburg, El Rick L Barth, PE 36749 '�' (-44 M 118 West Sixth Street, Suite 200 Glenwood Springs, CO 81601 970.945.1004 970.945.5948 fax E i i'LN I_JJ-%'AI •A L MAIN I EAJANUCE GUIDELINES i . r SGM Project # 96057U Revised 08 November 2021 Project lnfr�rn-rl 1.1 Description of Existing Site and Proposed Project 1.1.1 Description of Existing Sites The existing Boettcher Seminar Building (Boettcher) and proposed Center for Herbert Bayer Studies (Bayer), are located within the Aspen Meadows Campus owned by the Aspen Institute. The project sites are zoned academic with a planned development overlay. The site improvements were designed utilizing the latest edition (c. 2020) of the City of Aspen URMP. The site lent itself toward bio swales and rain gardens as the primary drainage tools for stormwater controls and quality. The approved plan and report indicated four areas of rain garden installation to account for the improvements for the Bayer/Boettcher site as well as the added bus lane on the Music Center site. These gardens were installed to minimize impact and retain historic flow patterns. As part of the basic maintenance the drainage report indicated typical practices for the lawn and landscape, as well as relevant references to the URMP Chapter 8 for maintenance and BMPs. Those are more elaborated on herein. For the purposes of reference, the segment of basic landscaping maintenance from the drainage report is reproduced here, with an additional section on the particular maintenance considerations referring to Chapter 8. 1.1.2 Description of Overall Site Drainage All drainage from roofs of the existing Boettcher Building, existing pods, and newly constructed Bayer building are all collected and conveyed north to a large rain garden that is just south of the SI Johnson Ditch. The drainage from the surrounding land scape around the buildings is also conveyed to the north via a system of area drains and pipes as well as grassy swales to the same large rain garden that receives the roof drainage. Drainage on the south side of the newly constructed Bayer building is collected by a footer drain and is conveyed to the drywell located to the south east of the building footprint. A foundation drain that surrounds Bayer also conveys drainage to the same drywell. The newly constructed system of asphalt paths drain to the surrounding landscape and consequently north to the rain garden through grassy swales. All drainage located north of the SI Johnson ditch, flows south into the ditch due to the grading of the new berm and landscape. There is one large rain garden located on Aspen Institute property itself located on the north side of the site just south of the SI Johnson ditch. All flows on site except for the south side of Bayer and the Bayer foundation drain are directed to this rain garden. The rain garden has a weir to allow excess flows into the SI Johnson ditch. The Newly paved bus lane on the Music Association property conveys all drainage flows north through a series of rain gardens. Runoff from the bus lane and pedestrian path is intercepted by a rain garden that runs the length of the pedestrian path until it terminates near the beginning of the turn. All drainage to the east of the turn flows north to a rain garden located behind the bus shelter location. The remaining runoff from the pedestrian path as well as excess flow from the median rain garden flow to a small rain garden to the west of the pedestrian path. From the small rain garden, a four -inch drain line conveys flows to the SI Johnson ditch. On the south side of the site a new sidewalk and parking area was constructed, runoff from this area is collected by a concrete valley pan that conveys the flow to a drainage inlet located on the east side of the bus lane entry/exit. 2.1 Drainage Maintenance The following maintenance recommendations were found in the Urban Drainage Flood Control District USDCM: Volume 3 Stormwater Quality (page 6-5 to 6-7) and will be used as a guide for the maintenance of the proposed facilities. Grass buffers and rain gardens should be inspected at least twice a year for cover and vehicle impacts. Trash and debris should be removed from the buffer at least twice a year. The buffer should be aerated once a year with holes of 2 inches in depth and no more than four inches apart. When aerating the buffer, sprinkler heads and shallow utilities should be marked to ensure they are not damaged. It is recommended to mow only when weeds need to be removed in the first 3 years. After the first 3 years the grass should be maintained at 6 inches or more in height. If grass buffers and rain gardens are no longer holding storm flows or are not draining in 24 hours, immediate maintenance is required. When drainage overflows to areas not intended to detain or convey flows immediate maintenance is required. Additional information on mowing the grass buffer is provided in Figure 1. Irrigation is recommended to maintain a healthy vegetation cover. In the early summer and fall, irrigation is typically needed less, but in July and August more irrigation is needed. If native grasses are used, irrigation should not be needed after establishment but could be useful during long dry periods. Although irrigation is necessary for the establishment of the grass buffer, overwatering could cause uneven growth which can inhibit the conveyance of runoff and should be avoided. Every year the irrigation system should be drained and blown out before the first winter freeze. The irrigation system should be inspected before reactivation in the spring. Fertilizers and herbicides should be used only on an as -needed basis and it is recommended to use biodegradable nontoxic fertilizers and herbicides. The following maintenance recommendations were found in the City of Aspen URMP. Figure 1. Required Maintenance Objective Frequency of Action Action Lawn Maintain a dense grass cover at a Routine- As needed or recommended by mowing recommended length of 2 to 4 inches_ inspection. Collect and dispose of cuttings oftsite or use a mulching nrowwer, Lawn care Use the minimum amount of biodegradable, Routine - As needed. nontoxic fertilizers and herbicides needed to maintain dense: grass cover, free of weeds.. Reseed and patch damaged areas. Irrigation Adjust the timing] sequence and water cover As needed. to maintain the required minimum soil moisture for dense grass growth. Do not overwater. Required Maintenance Objective Frequency of Action Action Litter Remove fitter and debris to prevent gully Routine -As needed by inspection, removal development, enhance aesthetics, and prevent floatables from being washed offsite. Inspections inspect irrigation, turf grass density, flow Annually after spring runoff and after each distribution, gully development, and traces of major storne (that is, larger than 1.0 inches pedestrian or vehicular traffic and request in precipitation)_ repairs as needed. Turf To tower the turf below the surface of the As needed when water padding becomes replacement adjacent pavement, use a level flow too high or trap frequent a problem, They spreader, so that sheet flaw is not blocked need for turf replacement will be higher if and will not cause water to black up onto the the pavement is sanded in winter to upstream pavement, improve tire traction on ice_ Otherwise, expect replacement once every 5 to 15 years, Rock Mulch Remove litter and debris frorn rock rnuich As needed. Expect to replace rack mulch strip- once emery 5 to 15 years depending on size and concentration of runoff area, Mowino recommendatinns fnr nracc hi if me nr vanes the Urban Drainage Flood Control District USDCM provided in the figure below. toted rain gardens that are included in Volume 3 Stormwater Quality are CSU Extension Recommendations for Mowing Manicured Turf (Source: T. Koski and V, Skinner, 2003) The two most important facets of mowing are mowing height and frequency. The minimum height for any lawn is 2 inches. The preferred mowing height for all Colorado species is 2.5 to 3 inches. Mowing to less than 2 inches can result in decreased drought and heat tolerance and higlivr incidence of insects, diseases and weds. Mow the lawn at the same height all year. There is no reason to inow the turf shorter in hate fall. Mow the turf often enough so no more than 1/33 of the grass height is removed at any single mowing. If your mowing height is 2 inches, inow the grass when it is 3 inches tall. You may have to mew a bluegrass or fescue lawn every three to four days duri ag the spring when it is actively growing but only once every seven to 10 days when growth is slowed by heat, drought or cold. Buffalograss lawns may require inuw ing once every 10 to 20 days, depending on how much they are watered. If weather or another factor prevents mowing at the proper time, raise the height of the inower temporarily to avoid cutting too much at one time. Cut the grass again a few days later at the normal mowing, height, To further address the specific rain gardens we refer to Section 8.5.3 with a focus on table 8.12 of the URMP, Maintenance Recommendations for Bioretention. For consistency and ease of maintenance techniques all the drainage BMPs are Bioretention, full infiltration rain gardens. The typical practices for such BMPs from the URMP has been reproduced here. If the rain gardens fail to detain water in the designated locations or are not draining in 24 hours after a storm event, they have failed and the maintenance steps outlined below should be carried out immediately. Mainteriar ce Sediment build-up may require periodic removal of sediments and plants when clogging reduces infiltration capacity to unacceptable levels. Access to facility must be provided to enable maintenance operations. Plant materials in areas prone to sediment build-up should be limited to grasses and groundcovers tolerant of periodic wet -dry cycles. Table 8,12 Maintenance Recommendations for Bioretention Required Action Maintenance Objectives Frequency Inspections Inspect detention area to determine if Routine — Annual inspection of the sandy growth media is allowing hydraulic performance. acceptable infiltration. Lawn mowing and vegetative care Occasional mowing of grasses and Routine — Depending on aesthetic weed removal to limit unwanted requirements. vegetation. Maintain irrigated turf grass as 2 to 4 inches tall and non - irrigated native turf grasses at 4 to 6 inches. Debris and litter removal Remove debris and litter from Routine -- Depending on aesthetic detention area to minimize clogging requirements. of the sand media. Landscaping removal and The sandy loam turf and landscaping Every 5 to 15 years, depending on replacement layer will clog with time as materials infiltration rates needed to drain the accumulate on it. This layer will need WQCV in 12-hours or less. May to be removed and replaced to need to do it more frequently if rehabilitate infiltration rates, along exfiltration rates are too low to with all turf and other vegetation achieve this goal. growing on the surface. The varied vegetation and surrounding surfaces may warrant minor modification to the frequency of inspections. For example, the median RG in the bus lane will more frequently pick up grit and silts where the rain garden north of the Boettcher building will likely have more leaves and vegetated impact.