Unless provided otherwise in this ordinance, all general use regulations, performance standards and provisions set forth in title 9, "Zoning", of the City Code for the Agriculture/Open Space (OS) District shall apply to any development on land within the Raccoon River PUD. To the extent that the provisions of this ordinance conflict with or are more restrictive than similar provisions provided elsewhere in the West Des Moines zoning ordinance, the provisions of this ordinance shall control. The following regulations, limitations, and restrictions shall apply to all land within the PUD:
A. Land Use: All land uses as set forth in title 9, "Zoning", of the City Code for the Agriculture/Open Space (OS) District as permitted and permitted conditionally shall apply except as designated below:
1. Allowed Uses: All uses as identified as permitted (P) or permitted conditionally (Pc) within the Open Space (OS) District shall be prohibited, except the following uses shall be permitted (P):
- | SIC 14: Mining and quarrying of nonmetallic minerals, except fuels. |
- | SIC 01: Agricultural production - crops. |
- | SIC 02: Agriculture production - livestock and animal specialties shall be allowed until December 31, 2043, or until such time that livestock production impacts the implementation and use of recreational amenities of the site. |
- | SIC 0272: Horses - private horse keeping shall be allowed; however, no structures for the boarding or protection of the animals shall be allowed to be constructed within the floodway or floodplain. One horse may be allowed for every two (2) acres of undisturbed area. |
- | SIC 48: Communications - antennas and satellite dishes shall be allowed to the extent that they provide communication services for the mining companies/operation only. |
- | SIC 494: Water supply. |
- | In addition, public parks and recreational trails (no specific applicable SIC codes) shall be allowed. (Ord. 1851, 11-30-2009) |
B. Excavation Setback: Excavation setbacks shall be as follows:
1. North: Minimum of one hundred forty feet (140') from the centerline of F90 (Raccoon River Drive). When mining is complete, there shall be a minimum of one hundred feet (100') of relatively flat area south of this one hundred forty foot (140') line to the top of the north bank of the lake. In areas where postreclamation berms are present south of this one hundred forty foot (140') line, the relatively flat area shall extend a minimum of one hundred feet (100') from the south toe of the berm to the top of the north bank of the lake. This relatively flat area shall be graded to drain toward the lake. If all available overburden material within this site has otherwise been utilized for the South Grand Prairie Parkway construction, neither mining company shall be required to bring soil material from off site to construct the necessary flat area.
2. East And South: As depicted on the updated site plans, in general, excavation limits shall be a minimum of fifty feet (50') from the property boundary, the edge of the existing trees within the riparian areas along the bank of the Raccoon River or a minimum of one hundred fifty feet (150') from the top of the bank of the Raccoon River (as it presently exists), whichever is greater. Unless specific permission is granted from the Director of Parks and Recreation, no trees shall be removed from the riparian areas along the river. The construction plans for the South Grand Prairie Parkway Bridge now require overbank excavation not previously identified. The excavation (mining) setback from this overbank shall be fifty feet (50') (and limited to within 825 feet of the east ROW line of S. Grand Prairie Parkway adjacent to the bridge), and Martin Marietta shall make a good faith effort to backfill in this area to reinforce the bank.
3. West: The excavation limits are graphically illustrated on attached exhibits C and D. The excavation limits have been revised to better accommodate the future widening of South Grand Prairie Parkway. The City acknowledges that sand and gravel mining is still expected to occur at approximately a 1:1 slope down from the setback line (on the surface) resulting in the potential need to backfill the toe of this slope (under water) prior to the future widening of this road. To assist with this future activity, Martin Marietta shall make a good faith effort to stockpile overburden within the phase 2 ROW for use by the City as backfill.
4. Johnson Creek:
a. A minimum setback of one hundred fifty feet (150') shall be provided from the eastern bank of Johnson Creek. Excavation may occur within up to fifty feet (50') of the creek bank if the area is backfilled to a width of one hundred fifty feet (150') for use as a greenbelt corridor and future trail location.
b. A minimum setback of seventy five feet (75') shall be provided from the western bank; there shall be no excavation closer than seventy five feet (75') to the bank regardless if backfilling is to occur.
c. If per agreement between the quarries and the City and upon obtainment of the appropriate permits by the City, the City desires to relocate Johnson Creek to the western edge of the site, a minimum thirty foot (30') setback shall be required from the eastern bank of the realigned creek.
5. Consent: With written consent of the abutting property owner, a zero foot (0') setback shall be required along interior property lines thus allowing the excavation pits of various operations to merge. Without written consent, each quarry shall maintain a minimum fifty foot (50') setback from the common property line. (Ord. 2231, 6-12-2017)
C. Building Setback: Buildings shall be set back a minimum of one hundred seventy five feet (175') from the centerline of F90 (Raccoon River Drive) and a minimum of fifty feet (50') from all other property lines.
D. Parking Setbacks: Off street parking areas shall be set back a minimum of one hundred twenty five feet (125') from the centerline of F90 (Raccoon River Drive).
E. Road Improvements:
1. Improvements: Unless otherwise agreed upon with the City as part of the reclamation, all access and internal drives may be gravel or paved (PCC or ACC) at the discretion of the property owner. Curb and gutters typically required by Code for streets and parking areas shall not be required due to the long range postmining land use intentions.
2. Dust Suppression: Best Management Practices for dust suppression shall be used to mitigate dust. (Ord. 1851, 11-30-2009)
3. Additional Improvements: Additional road improvements associated with or assistance in the construction of South Grand Prairie Parkway, if any, shall be as agreed upon between the quarries and the City as part of a separate road agreement. (Ord. 1851, 11-30-2009; amd. Ord. 2231, 6-12-2017)
4. Overburden Use: Unless otherwise refused by the City, the City shall have access to and the first right to utilize quarry overburden, not otherwise required of the reclamation plan. Stockpiling, physical placement and compaction requirements and details, if any, shall be identified within the separate road agreement and agreed upon by both the quarries and city.
F. Buffers: Buffering between districts or parcels and uses shall not be required as set forth in title 9, chapter 19 of the city code.
1. Buffers shall be provided as follows:
a. North: A minimum fifty foot (50') wide buffer shall be provided along F90 (Raccoon River Drive). Said buffer shall be located a minimum of ninety feet (90') from the centerline of F90 (Raccoon River Drive).
b. East:
(1) A minimum one hundred foot (100') wide buffer shall be provided adjacent to the property line along that portion of the property in proximity to any existing residences or businesses on the adjacent property unless written consent from adjoining property waiving the buffer requirement is provided to the city. The existing undisturbed vegetation shall satisfy buffer requirements.
(2) No buffer shall be required along that portion of the property that is not in proximity to a business or residence; however, as indicated previously in subsection B, "Excavation Setback", of this section the existing riparian areas along the north and west bank of the river as generally indicated on the updated site plans shall not be disturbed unless specifically authorized by the director of parks and recreation.
c. South: None required; however, as indicated previously in subsection B, "Excavation Setback", of this section the existing riparian areas along the north bank of the river shall not be disturbed unless specifically authorized by the director of parks and recreation.
d. West: None required.
2. The soil berming and vegetation measures which have been implemented for buffering along the northern boundary as required by Dallas County as part of the original mining permit shall be maintained until completion of mining activities, including material stockpile removal. Visual screening of the mining operation has been achieved through the implementation of a soil berm approximately twelve feet (12') in height in conjunction with the establishment of landscape vegetation. Due to the intended postmining land use and the desire for views into the site from the abutting F90 (Raccoon River Drive) and other areas to the north, upon completion of mining operations, portions of the berm may be reshaped thus opening up views into the lake that was created during the mineral extraction operation. Excess dirt, if any removed from the berms may either be incorporated into an area within close proximity to where it is removed, or at the city's effort and expense, the dirt may be relocated to alternate areas. Unless otherwise agreed upon, the quarries shall not be required to truck the excess dirt from the berms to alternate locations within the site.
G. Pedestrian Trails: The general location of desired recreation trails are indicated on the reclamation plan. Mineral extraction operations and reclamation efforts shall be such to provide suitable and desirable trail implementation.
H. Lake Edge: The postmining land use intention for this site is for a recreational lake accommodating shoreline fishing, swimming and boating. In anticipation of these intended uses, a variety of underwater slopes are desired; therefore, adherence to the city's requirement of a maximum grade of one to ten (1:10) (1 foot vertical rise to 10 feet horizontal run) within the first fifty feet (50') of water area shall not be required. In lieu thereof, the applicant shall work with the parks and recreation department to identify specific areas and details of the lake edge treatment and underwater grades desired. Said standard details shall be included within the reclamation plan or associated reclamation text document, if prepared for the property. Although every effort should be made to provide suitable slopes for the intended postmining uses indicated for the lake's edge (swimming area, fish habitat, wetland restoration, etc.), it is realized that due to the nature of this type of mineral extraction and the presence of water throughout the extraction process that the traditional grading of soil to achieve specific slopes is not possible. The applicant will be able to place soil along an edge only to a distance that traditional excavators and dump trucks allow; this soil will reach the natural angle of repose; in general, this angle of repose shall be considered acceptable.
Because a natural recreational area is anticipated as the postmining land use, it is desired that the lake be of an organic shape rather than a rectilinear typical of extraction operations. Measures to ensure a natural appearance to the lake should be included within the reclamation plan.
I. Erosion Control:
1. Silt fences shall be installed where reasonably needed to control off site erosion of nonvegetated soils, other than agriculture cropland, that do not drain into the quarry. When feasible, all uncontrolled erosion material and debris should drain to the quarry and not toward the river or creek.
2. All single points of discharge of stormwater leaving the site shall have erosion protection.
3. All requirements of any applicable national pollutant discharge elimination system (NPDES) permit shall be complied with.
J. Noise: All activities associated with the extraction and sale of minerals from the site shall adhere to the limitations and requirements as set forth within title 4, chapter 7, "Noise Control", of the city code, except as otherwise amended in this ordinance.
1. To aid in adherence to the provisions of the noise control ordinance, the following measures shall be implemented:
a. Electrical Equipment: As available, electrical equipment shall be utilized in the mining operation in lieu of diesel powered equipment.
b. Noise Reducing Material: Urethane or similar noise reducing material shall be used to line all chutes.
c. Backup Alarms: Backup alarms for equipment routinely used in the day to day mining operations shall be set to the quietest setting allowed within federal safety standards.
d. Material Loading: A good faith effort shall be made to limit operations between the hours of six o'clock (6:00) A.M. to six o'clock (6:00) P.M. on weekdays and six o'clock (6:00) A.M. to one o'clock (1:00) P.M. on Saturday. However, it is recognized that due to the requirements that some customers conduct construction activities during off peak hours, some loading of materials may need to occur outside of these stated hours. The director of development services should be notified of any special construction projects which necessitate an extended period of off peak hour loading. At the director's discretion, the request for temporary extended hours may require the approval of the city council. All efforts shall be made to minimize noise from these loading operations so as to minimize disturbance to residential properties and businesses within the area. If multiple complaints are received, at the discretion of the director of development services, mining operations and customer loading outside of the defined hours may be prohibited.
e. Crushing Activities: Rock crushing activities for both quarries of material mined within the site (no material trucked in from off site) shall be allowed annually for a total of thirty (30) business days between October 1 and April 1 for each mining operation. The thirty (30) day period for rock crushing activities for each mining operation may occur concurrently or be divided into separate crushing periods; however, no crushing shall be conducted between May 1 and September 30 of a calendar year without specific approval of the city council. Rock crushing activities shall be limited to between the hours of eight o'clock (8:00) A.M. to six o'clock (6:00) P.M. on weekdays; no crushing activities shall be allowed on either Saturday or Sunday without specific council approval. To the greatest extent possible, placement of crushing equipment should be located near the current processing plant areas or otherwise as far away from residential properties as possible. All feasible noise and dust minimizing measures should be implemented to help mitigate potential impacts of crushing activities on neighboring properties. Following completion of annexation to the city by each mining operation and within one year of the conclusion of the first thirty (30) day crushing period, the city shall hold a public hearing before the city council to evaluate the continuation of rock crushing activities. The city council shall have the unilateral right to prohibit any further crushing activities if, in the judgment of the city council, it is determined that adverse impacts from the crushing activities on the surrounding area warrant termination. For purposes of this ordinance, the rock crushing activities will constitute "adverse impacts" if: 1) on three (3) or more occasions between October 1 and April 1 during which rock crushing has occurred, the crushing activities have failed to meet all federal, state and local rules and regulations, including specifications and conditions imposed by the Iowa department of natural resources related to fugitive dust emissions; or, 2) on three (3) or more occasions between October 1 and April 1 during which rock crushing has occurred, the noise generated from each quarry's crushing activities exceeds the maximum decibel level allowed by the city's noise ordinance (as measured at the receiving property); or, 3) a combination of both 1) and 2) herein totaling three (3) occasions between October 1 and April 1 during which rock crushing has occurred. The council shall also have the authority upon evaluation of crushing operations to lessen or increase the above stated restrictions as they apply to rock crushing activities. Following the first public hearing, but no less than every thirty six (36) months thereafter, the City may require additional public hearings before the City Council to evaluate the impact of the crushing activities on the surrounding area. Failure of the City Council following a public hearing to determine that the rock crushing activities are creating adverse impacts on the surrounding area, or failure of the City Council to hold subsequent public hearings, shall allow the continuation of rock crushing activities. A finding by the City Council following a public hearing that the rock crushing activities of one mining company are creating adverse impacts on the surrounding area shall not prohibit the continuation of rock crushing activities by the second mining company if it is determined that the rock crushing activities of the second mining company are not creating adverse impacts on the surrounding area. A public hearing regarding the continuation of rock crushing activities shall not be construed to allow review of other activities permitted under this ordinance, which shall be conducted as provided in this ordinance.
K. Lighting: All lighting fixtures, security and otherwise, shall be downcast. All measures necessary to eliminate light spillover to properties outside of the PUD perimeter boundaries shall be implemented; in general, light levels at the perimeter boundary of the PUD shall not exceed one foot-candle.
L. Signage: A ground sign shall be allowed at each primary entrance; any modifications to the existing ground signs shall abide by provisions within the Sign Code. No billboard signs shall be allowed on any land within the PUD boundaries. (Ord. 1851, 11-30-2009)