(a) Undeveloped Land.
(1) Streets. Streets shall conform to the Official Thoroughfare Plan of the Village of Yellow Springs and shall be dedicated by the owner. Pavements of streets and construction of water and sanitary sewer systems, shall be according to Greene County specifications, especially those found in Article 8 of the Subdivision Regulations of Greene County, Ohio, as amended. Construction of curbs, gutters, driveway aprons and associated storm sewers shall be according to the Village's storm water management design standards in Section 1226.06
(a)(7), the driveway standards in the Zoning Code Section 1260.03
(a) and standard plans on file with the Village. Calculation of potential runoffs and the storm sewer system so dictated shall be arrived at using the methods provided for in Section 1226.06
(a)(7) Storm Water Management Systems. Development of individual lots within an approved subdivision shall be required to follow the Stormwater Guidelines for Low Impact Development contained in the appendix following the text of these subdivision regulations.
Low Impact Development (LID) will be considered by the Planning Commission in lieu of a conventional stormwater system design. Stormwater management plans that use natural and engineered infiltrations and storage techniques in order to control stormwater where it is generated to control runoff may be presented. The LID shall include such designs as engineered systems that filter stormwater from impervious surfaces, that retain stormwater for slow infiltration, water collection systems, vegetated areas, and modifications to infrastructure. Low Impact Development designs may be presented if stormwater calculations prove its capabilities for controlling runoff and if the LID does not burden the Village with long-term maintenance issues. Sidewalks/pedestrian walkways must be included in the design of any new subdivision in the Village following ADA standards. LID designs for sidewalks will be considered by the Planning Commission in lieu of conventional designs. The LID plan shall be prepared by a licensed engineer at the expense of the developer. The LID plan shall be reviewed and formally approved by a Village designated engineer at the expense of the developer.
(2) Alleys. Alleys shall be twenty feet in width. Alleys shall be constructed according to Village of Yellow Springs specifications. Dead-end alleys are prohibited.
(3) Sidewalks. ADA compliant sidewalks shall be required along all public streets. ADA compliant sidewalks along streets shall be provided as required by the Commission and may include use of "black top" in lieu of concrete and of one-side-of-the-street installation. Such sidewalks shall meet sidewalk construction specifications approved by the Village of Yellow Springs.
(4) Electric. An underground electric distribution plan for the entire subdivision, prepared by a licensed engineer, shall be formally approved by a Village-designated engineer at the expense of the subdivider.
(5) Easements. Easements with right-of-way widths up to ten feet, as required, shall be provided on rear yard lot lines and along the side yard lot lines in addition to those required by the developer.
(6) Lots. Every lot shall abut on a street and double frontage lots shall be avoided except where such lots will reduce curb cuts on heavily traveled thoroughfares. Area, dimensions and layout of lots shall be in conformity with the Village of Yellow Springs Zoning Code. Uncommon lot configurations may be incorporated into a development where such division poses no apparent nuisance and the Commission deems it appropriate. Approval of such lots shall be granted upon review of the following additional criteria:
A. Adequate access to such lots is provided and poses no nuisance to adjoining lots. Adequate access shall accommodate emergency needs, parking and any other requirements specific to the location.
B. The relation to the adjoining lots is acceptable in that required setbacks can be maintained, adequate privacy is preserved and apparent nuisances (light, noise) are avoided.
C. A minimum frontage of twenty feet shall be required for all such lots.
D. Uncommon lot configurations must be approved by the Planning Commission.
(7) Stormwater Management Systems.
A. General requirements. All storm sewer designs shall be in accordance with the following standards. All designs shall protect from flood damage and inundation by stormwater to any dwelling. Drainage water entering the watershed shall be collected and routed from the area in approximately the same location and manner that existed prior to the construction of the improvements. Design of the drainage facilities within the drainage area shall be such that they will not divert drainage area from one watershed to another.
B. Design of drainage facilities
1. For any proposed development resulting in one acre or less of impervious area: A stormwater management plan as stated in the Stormwater Guidelines for Low Impact Development is required. The Stormwater Guidelines for Low Impact Development is contained in the appendix following the text of these subdivision regulations. The storm water management plan must be maintained by the property owner into perpetuity. The stricter criteria outlined in Section 1226.06(a)(7)B.2. will be required for any Planned Unit (PUD) or Pocket Neighborhood Development (PND). If more than one lot is proposed for development, the combined acreage of the lots impervious area will determine the stormwater management requirements.
2. For proposed developments resulting in more than one acre of impervious area:
a. Hydrologic design. All drainage ways shall be designed in accordance with the following criteria. Exceptions to this criteria may be considered if green infrastructure designs are implemented:
i. Major waterways: Major waterways are defined as those with a tributary area in excess of four square miles. Major waterways shall be designed for an average recurrence interval of 100 years.
ii. Secondary waterways: Secondary waterways are defined as those with a tributary area of between one and four square miles. Secondary waterways shall be designed for an average recurrence interval of fifty years.
iii. Minor waterways: Minor waterways are defined as those with one square mile or less of tributary area. Minor waterways shall be designed for an average recurrence interval of twenty-five years for open channels and culverts.
iv. Roadway storm sewer networks: All roadway storm sewer shall be designed for an average recurrence interval of ten years.
b. Hydraulic design.
i. The design hydraulic grade line for any closed or open waterway, bridges or culverts shall be designed to contain the twenty-five-year rainfall frequency within the proposed system. Storm sewers designed as part of a road system with curb shall be designed so that the hydraulic grade line shall be no higher than the inlet grates for a design discharge of the twenty-five-year design discharge (Q).
ii. For all roadway design improvements or developments, catch basins shall be so placed along the streets that the width of flow does not impede traffic. For acceptable spread requirements along a roadway, reference Ohio Department of Transportation Location and Design Volume 2, the most current edition.
iii. The depth of flow or ponding for a 100-year average recurrence interval storm shall not exceed a level which would cause inundation or damage to any dwelling constructed within the project area.
iv. Site grading within the development shall be such that all lots will readily drain. Lots shall have a one percent minimum slope in grass areas. Overland flow on lots shall be limited to a maximum distance of 300 feet unless approved by the Village of Yellow Springs.
v. Bridges spanning open waterways shall have minimum freeboard above water surface of two feet.
vi. The minimum velocity for any closed or open conduit shall be 2.5 feet per second under gravity flow conditions.
c. Structural design. Catch basins, manholes, inlet structures, etc. placed within an improvement or development shall conform to standard plans on file with the Village. Structural design of all drainage facilities shall be subject to the approval of the Village of Yellow Springs.
i. Channels/swales:
(a) Minimum bottom width of constructed channels shall be two feet.
(b) Each channel constructed shall have side slopes of 3:1 or flatter.
(c) All permanent drainage swales shall be shown on the construction plans with easements on the final plat.
(d) Maintenance of all drainage swales through a development shall be the responsibility of the developer/owner.
(e) Bank stabilization and stream bed stabilization, along constructed or natural channels, will be required if the channel velocities are sufficient to cause bank or invert erosion. The top of bank shall be so graded that side drainage will enter channels only at points where structures are provided to prevent bank erosion. Side drainage flow shall enter the channel as nearly parallel with stream flow as possible. Earth channels shall be seeded or sodded depending on the velocity of flow within the channel.
ii. Closed conduits:
(a) Storm drainage within the development, which is capable of being transmitted in a pipe forty-eight inches or less in diameter, shall be carried in a closed conduit. At the request of the applicant and their design engineer, this requirement may be waived. The reason for this waiver shall be to meet the requirements of the Ohio Environmental Protection Agency Construction Permit. The minimum conduit size shall be twelve inch pipe.
(b) Minimum clearance between top of pipe and top of surface shall be two feet. All pipes with clearance less than two feet shall be reinforced concrete pipe. The alignment of closed conduits shall be as nearly straight as practical without bends and angle points; manholes shall be provided at all angle points and at intervals not to exceed 300 feet along the conduit unless submitted for approval with proper documentation. Inverted siphons shall not be permitted except for temporary structures.
(c) All pipe, bedding and backfill shall be designed in accordance with the Ohio Department of Transportation Design Manual. Field tile/single wall storm tile is NOT allowed. Ditch protection shall be required if the ten-year flow velocities in a channel or waterway exceed four feet per second for soil ditches or six feet per second in sodded ditches. If the exit velocity from a storm sewer exceeds the allowable velocities, an energy dissipating device (i.e. stilling basing, dumped rock) may be necessary.
C. Stormwater runoff control criteria for retention/detention basins. Any development which increases the runoff rate and volume shall be required to control the discharge rate of runoff prior to its release to its off-site outlet.
1. Any increase in the volume of site surface drainage water resulting from accelerated runoff caused by site development shall be controlled so that the post development peak discharge rate does not exceed that of the pre-development peak discharge rate, for all twenty-four-hour storms between a one-year frequency and the critical storm frequency as determined below. The method by which an applicant shall determine changes in rates and volumes of runoff is presented in the U.S. Department of Agriculture, Engineering Division of the Soil Conservation Service, Urban Hydrology for Small Watersheds, Technical Release No. 55, June 1986 or most current edition. To find the critical storm frequency for which additional control will be needed, the applicant shall:
a. Determine the percent increase in runoff volume for a one-year frequency, twenty-four-hour storm occurring on the development area.
b. Determine the critical storm frequency for which additional control is needed by using the percent increase in runoff volume, derived in a. above, in Table 1.
c. Control the post development storms of a frequency between one year and the critical storm determined in b. above, so as to be equal to or less than the pre-development peak runoff rate for a twenty-four-hour one-year frequency storm.
d. Storms of less frequent occurrence (longer return periods) than the critical storm up to the 100-year storm have peak runoff rates no greater than the five-year frequency peak runoff rates. Consideration of the one, two, five, ten, twenty-five, fifty and 100-year storms shall be considered adequate in designing and developing to meet this standard.
e. In no instance, shall the post developed peak runoff rate exceed half of the capacity of the immediate downstream receiving drainage system.
D. Critical year storm calculation: (1-year Post - 1-Year Pre) x 100% (1 Year Pre)
1. Table 1:
DETERMINING STORM FREQUENCY FOR WHICH CONTROL IS NEEDED | ||
Percent Increase in Runoff Volume From a 1 Year Frequency, 24 Hour Storm | ||
equal or greater than (percent) | less than (percent) | Storm Frequency (years) |
DETERMINING STORM FREQUENCY FOR WHICH CONTROL IS NEEDED | ||
Percent Increase in Runoff Volume From a 1 Year Frequency, 24 Hour Storm | ||
equal or greater than (percent) | less than (percent) | Storm Frequency (years) |
- | 10 | 1 |
10 | 20 | 2 |
20 | 50 | 5 |
50 | 100 | 10 |
100 | 250 | 25 |
250 | 500 | 50 |
500 | - | 100 |
E. Post construction runoff control. The drainage design shall incorporate the following post-construction storm water management requirements. These requirements are necessary in order to reduce increases in non-point pollution caused by stormwater runoff, minimize the total runoff volume which flows from a site following increases in impervious area by development, and minimize changes in the watershed hydrology inherent with development.
1. The post construction requirements should meet or exceed the most current Ohio Environmental Protection Agency Construction general permit.
2. The site-specific characteristics shall be considered in the design.
a. Minimum orifice sizes should be considered in areas of soils with low permeability rates.
b. Infiltration systems in sites over well field areas shall require the approval of the Health Department.
F. Drainage plan. The development drainage map shall include sufficient data for the Village to check the feasibility of the drainage system as proposed by the developer. The following data shall be provided.
G. Hydrologic calculation. At all critical points within the development including catch basins:
1. Tributary drainage areas delineated on the map.
2. Times of concentration.
3. Intensity.
4. Runoff coefficients.
5. Design flow.
H. Hydraulic calculations.
1. Sufficient documentation to indicate the results of the investigation into the adequacy of the downstream drainage system to handle the runoff from the proposed development.
2. This will determine the maximum allowable release rate for the proposed development and, in turn, the amount of stormwater storage that will be required.
3. The plan and profile of all drainage ways shall be provided, imposed upon which shall be the design energy and hydraulic grade lines.
4. Sizes and types of drainage improvements, including special structures, typical sections, right-of-way width and fencing.
5. Supporting calculations for upstream and downstream channel capacities as they affect overflow, erosion or backwater within the development. Such calculations shall be substantiated by such additional information as is required to determine profile and cross section of the upstream and downstream channel reaches under consideration.
6. Sufficient contours and grading details to indicate proposed street grades and elevations throughout the development.
I. Construction plans. The final construction plans for drainage within the development shall conform to the above provisions and to any special conditions as required by the Village of Yellow Springs in approving the tentative plans. Such construction plans for drainage shall be approved by the Village of Yellow Springs prior to construction of any drainage facilities within the development. The final construction drawings shall contain the locations, widths, names of existing streets, railroad rights-of-way, easements, parks, permanent buildings, and corporation and township lines; location of wooded areas and other significant topographic and natural features within and adjacent to the development property for a minimum distance of 200 feet.
1. Type of Surface C Factor
Roof surface 0.95
Bituminous or concrete pavement 0.90
Gravel pavements 0.70
Impervious soils 0.65
Impervious soils with turf 0.50
Slightly pervious soils 0.40
Slightly pervious soils with turf 0.30
2. The designer should investigate the capacity of the downstream drainage facilities to determine if they will be adequate to handle the design flow from this particular development. If the downstream facilities are inadequate, it may be necessary to provide on-site detention or retention basins to limit the flow to an amount which the downstream system can accept.
3. A site grading plan with minimum finish grade shall be required by the design engineer as a part of the construction plans. At a minimum, first floor elevations should be shown. If minimum basement elevations are stated in the plans, developer/owners must follow the plans or assume all risk. The grading plan shall show all intended direction of surface water flow.
4. All plans, calculations and design work need to be signed and stamped by a professional engineer, and formally approved by a Village designated engineer at the expense of the developer.
J. Stormwater Runoff Policy. The design standards are based on the policy that land uses and developments which increase the runoff rate or volume shall be required to control the discharge rate of runoff prior to its release to off-site land. The purposes of this policy are:
1. Permit development without increasing the flooding of other lands.
2. Reduce damage to receiving streams and impairment of their capacity that may be caused by increases in the quantity and rate of water discharged.
3. Establish a basis for design of a storm drainage system on lands below undeveloped areas which will preserve the rights of property owners and assure the long-term adequacy of storm drainage systems.
4. This runoff control policy applies to all land developments not specifically exempted below. Exemptions are appropriate for certain land use activities which clearly do not generate significant increases in stormwater runoff. The following land uses and developments are within this exemption category:
a. Land preparation for agricultural crops, orchards, woodlots, sod farms, and nursery operations.
b. Land grading or leveling for erosion control under direction of the local soil conservation district.
K. Planning Guidelines for Detention Basins.
1. Detention basins serve to capture and temporarily store the surface water runoffs that result from urban development. This temporary storage allows for the release of the storm runoff at discharge rates which are acceptable to the receiving waterway. On-site provision for detention storage shall follow these approaches:
a. The release rate and volume of detention storage shall be based on the Village of Yellow Springs design requirements and standards.
b. Recreational or aesthetic uses should be maximized where possible and feasible.
c. Any development in which the drainage exits the corporation limits of the Village and enters onto county, township or state jurisdiction shall be reviewed by the appropriate government official. A statement of comments must be submitted by that official in writing.
d. Stormwater runoff of the pre-developed "sheet flow" characteristics versus post-developed "point source" release of the stormwater exiting the site shall be taken into design consideration. Runoff from a proposed development shall provide downstream energy dissipation.
e. Stormwater design shall take into consideration and provide adequate drainage for neighboring upstream property surface or subsurface water entering onto the proposed development or site. Offsite water may flow through the property and is not subject to storm control.
f. All storm tiles found entering a proposed development or found while excavating need to be investigated. If the storm tile is found to be in non-working condition, the storm tile must be replaced.
g. If a storm tile is going to be abandoned, it must be totally excavated and destroyed within the development.
L. Detention basins. The bottom of the basin shall have a minimum slope of one percent.
M. Retention basins.
1. In order to provide for better management of the water, retention basins shall have a permanent water area of at least one-half acre. The permanent water area shall have an average water depth of four feet and no extensive shallow areas.
2. In excavated lakes, the underwater side slopes shall be stable.
3. A safety ledge of two-foot-deep, five-feet-wide is required around the perimeter of the basin.
N. Detention and retention basins.
1. All developments/site improvements requiring detention/ retentions shall have a homeowner’s association established as a part of the plat restrictions. The association shall be responsible for all pond and drainage swale maintenance.
2. There shall be a minimum three-foot-wide berm at a two percent slope between the right-of-way and the top of the basin slope.
3. Slopes on the sides of the basin shall have a maximum slope of 3 to 1. This includes both sides of any constructed levy.
4. The minimum diameter of any outlet conduit shall be one foot.
5. Safety measures shall be provided for any pipe or opening to prevent children or large animals from crawling into structures.
6. Retention pond design and maintenance shall include algae control with pond additives. Fountains shall also be considered but are optional.
7. Managed natural landscapes shall be maintained as outlined in Section 674.02(a)(4) of the Weed ordinance. If turf grass is planted, it shall be cut regularly, no less than five times a year by the homeowner’s association or by an approved agreement with the Village of Yellow Springs Public Works Department.
8. Debris, trash removal and other necessary maintenance shall be performed after each storm to assure continued operation in conformance with the design.
9. There shall be a minimum of one-foot freeboard between the 100-year storm elevations and the top of the levy or embankment containing the basin.
10. All basins shall have an emergency overflow.
11. The Village shall be notified prior to any adjustments to the approved outlet structure to any detention or retention basin. No adjustment shall be made until approved by the Village.
12. The surface area opening for catch basin inlets shall be equal to or greater than the design overland flow contributing water to that basin.
13. Detention/retention basin shall be located within an easement and have a means of access available to the Village.
14. The site developer may pass on maintenance responsibilities to the respective owner/homeowners association via a maintenance agreement. The maintenance agreement must be approved by the Village and recorded on the final plat at the Greene County Recorder's Office.
O. For specific stormwater design solutions, please refer to the Appendix: Stormwater Guidelines for Low Impact Development following the text of these subdivision regulations.
P. "As-built" drawings.
1. These drawings are required for all basins to assure compliance with all applicable requirements. This requirement shall include calculations to confirm that the basin and outlet were constructed to function as designed.
2. Drawings are also required for other types of designs to mitigate stormwater. This shall include calculations to confirm that the construction will function as designed.
Q. Plan approval. These drawings and calculations shall be certified by a registered professional engineer. The construction of stormwater drainage improvements shall be subject to the approval of the Village of Yellow Springs Public Works Department, and a Village designated engineer at the expense of the developer.
(8) Street trees. All subdivisions shall contain plans for tree planting along public streets of the new development and shall be approved by the Village of Yellow Springs Public Works Department and/or the Planning Commission. The following guidelines shall be followed:
A. Tree selection shall be taken from the Village of Yellow Springs Recommended Trees list, contained in Appendix B following the text of these Subdivision Regulations.
B. Existing trees over two inches in caliper may be used to satisfy these requirements.
C. The minimum size (trunk caliper) for new trees shall be no less than one and one-half inches.
D. The developer shall be required to maintain the trees for three years after the trees are planted and to replace any tree that dies within such three-year period. At the end of three years, the trees become the responsibility of the Village of Yellow Springs.
E. The spacing between large trees (a mature height of fifty feet) shall be forty-five to fifty feet; the spacing between medium trees (a mature height of thirty feet to fifty feet) shall be thirty-five to forty feet, and the spacing between small trees (a mature height of ten to thirty feet) shall be twenty-five to thirty feet.
F. Tree location shall be at least twenty feet from street intersections, twenty-five feet from utility poles and ten feet from fire hydrants.
G. Tree lawns shall be a minimum of six feet wide between the sidewalk and curb or street edge.
(9) Interior landscaping. All subdivisions shall include an interior landscaping plan that shall consist primarily of new tree planting or the preservation of existing trees and/or hedges within the development site, and following the managed natural landscaping requirements outlined in Section 674.02
(a)(4) Weeds ordinance.
A. Preservation of existing landscaping materials. All trees having a trunk diameter of six inches or greater, as measured twenty-four inches from ground level, shall be preserved unless such trees are exempted as follows:
1. Trees within public rights-of-way or utility easements, or a temporary construction easement as approved by the Planning Commission;
2. Trees within the ground coverage of proposed structures or within twelve feet from the perimeter of such structures;
3. Trees within the driveway access to parking or service areas or proposed areas to service a single-family home;
4. Trees that, in the judgment of the Village Tree Committee or some other agent with similar expertise, are damaged, diseased or over mature, interfere with utility lines or are an inappropriate or undesirable species for the specific location.
B. Preservation of exempted trees. It is encouraged that exempted trees subject to destruction be preserved by relocation and replanting whenever possible.
C. Tree planting requirements for all new developments. The following landscape requirements shall apply:
Use | Requirements |
All residential, residential PUD, and residential site plan review districts. | Tree plantings equal to one-half inch in tree trunk size for every 150 square feet in ground coverage by a single-family structure. Such plantings shall be required within the property lines of each structure. |
Educational Institution, Office/Research and General Business Districts. | In addition to the requirements of Ch. 1264
, landscaped areas equal to 100 square feet for 1,000 square feet of building ground coverage or fraction thereof. Such landscaped areas shall contain trees, planting beds, hedges, fences, walls, earth mounds, benches or other materials designed and located complementary to the structures. |
Light Industrial, commercial and industrial PUD. |
D. New tree plantings. If new tree plantings are required for conformance to the landscaping requirements of this chapter, the applicant shall indicate on the landscape plan the location and size of such tree plantings. If such landscape plan is approved, the applicant shall plant such trees within one year or at the next planting season after issuance of a building permit.
(b) Land Abutting Existing Streets. Where lots are platted along an existing street, the developer may be required to improve the street and storm sewer, water and sanitary sewer systems and facilities and to provide ADA compliant sidewalks and street trees as specified in subsection (a) hereof insofar as such improvements are applicable.
(c) Utilities Review. As a condition of a minor subdivision or replat, a utilities review must be completed prior to the start of construction. For all subdivisions creating new buildable lots, applicants are required to provide proof from a licensed plumber to ensure that sewer laterals conform to regulation or pay for camera inspection of the lateral through the Public Works Department. In addition, the applicant shall verify with Public Works and other private utilities that the utility lines conform to regulations.
(Ord. 91-12. Passed 12-2-91; Ord. 94-9. Passed 6-6-94; Ord. 2017-18. Passed 9-18- 17; Ord. 2017-40. Passed 11-7-17; Ord. 2020-27. Passed 10-19-20; Ord. 2022-10. Passed 4-18-22.)