Lee's Summit

Applicant is requesting waivers to the Design and Construction Manual for limited grading within the stream buffer, and elimination of the requirement to perform detention for a peripheral drainage area which has been reduced in size from the existing condition. Staff supports the requests, but the waiver request is missing the following items: 1) existing condition and proposed condition drainage area for the peripheral drainage area, 2) quantifiable decrease in the amount of stormwater release for the peripheral drainage area at release point #2 from the existing condition, 3) exhibit showing the existing stream buffer labeled, and the limits of "transitional grading" described in the waiver request in measurable terms, 4) total area of "transitional grading" within the stream buffer, and 5) discussion why a stream assessment is not warranted for the stream buffer waiver.

DE C&O #01 Eng Plans – FP/PP

All required engineering plans and studies, including water lines, sanitary sewers, storm drainage, streets and erosion and sediment control shall be submitted along with the final plat and approved prior to the approval of the final plat. All public infrastructure must be substantially complete, prior to the issuance of any building permits.

DE C&O #02 Master Drainage Plan

A Master Drainage Plan (MDP) shall be submitted and approved in accordance with the City’s Design and Construction Manual for all areas of the development, including all surrounding impacted areas, along with the engineering plans for the development. The MDP shall address drainage level of service issues on an individual lot basis.

DE C&O #03 Eng & Insp Fees

All Engineering Plan Review and Inspection Fees shall be paid prior to approval of the associated engineering plans and prior to the issuance of any site development permits or the start of construction (excluding land disturbance permit).

DE C&O #04 Cert FA or Escrow

All subdivision-related public improvements must have a Certificate of Final Acceptance prior to approval of the final plat, unless security is provided in the manner set forth in the City's Unified Development Ordinance (UDO) Section 7.340. If security is provided, building permits may be issued upon issuance of a Certificate of Substantial Completion of the public infrastructure as outlined in Article 3, Division V, Sections 3.540 and 3.550 and Article 3, Division IV, Section 3.475 of the UDO, respectively.

DE C&O #05 As-Graded MDP

The As-graded Master Drainage Plan shall be submitted to and accepted by the City prior to the issuance of a Certificate of Substantial Completion and prior to the issuance of any building permits for the development.

DE C&O #06 Land Disturbance

A Land Disturbance Permit shall be obtained from the City if groundbreaking will take place prior to the issuance of a site development permit, building permit, or prior to the approval of the Final Development Plan / Engineering Plans.

DE C&O #07 Easements

All permanent off-site easements, in a form acceptable to the City, shall be executed and recorded with the Jackson County Recorder of Deeds prior to approval of any engineering plans. A certified copy shall be submitted to the City for verification.

DE C&O #08 Changes to MDP

A restriction note shall be included on the final plat stating: “Individual lot owner(s) shall not change or obstruct the drainage flow paths on the lots, as shown on the Master Drainage Plan, unless specific application is made and approved by the City Engineer."

DE C&O #10 Mowing ROW

Upon approval of the proposed rezoning by City Council, the applicant will become responsible to provide the appropriate level of right-of-way maintenance (mowing) during each growing season with the defined area abutting their property as defined and outlined in the City’s Mowing Policy, approved by Council on November 3, 2005.

DE C&O #12 Cut & Fill

Any cut and / or fill operations, which cause public infrastructure to exceed the maximum / minimum depths of cover shall be mitigated by relocating the infrastructure vertically and / or horizontally to meet the specifications contained within the City’s Design and Construction Manual.

DE C&O #13 ADA Sidewalk Ramps

All ADA sidewalk ramps shall be constructed by the developer at the time the street is constructed.

DE C&O #14 Common Area Sidewalks

All sidewalks adjacent to a common area tract, unplatted land or any land where no structure is intended to be built, and is required, shall be constructed by the developer at the time the street is constructed.

DE Commercial Detention Basin

The applicant shall submit and the City shall accept an “As-built / As-graded” detention basin plan prior to issuance of a Certificate of Substantial Completion.

Limits of the stream buffer shall be shown on the plat, along with stream buffer language and definition in a form prescribed by the City.

Code Statement

All issues pertaining to life safety and property protection from the hazards of fire, explosion or dangerous conditions in new and existing buildings, structures and premises, and to the safety to fire fighters and emergency responders during emergency operations, shall be in accordance with the 2018 International Fire Code.

10' Shared-use path required along Ranson.

Public water line loop is now shown along Cape Dr. to the east, which will be installed along unplatted land until the 3rd phase. This is problematic in that the water main loop will be installed overland, with maintenance being an issue. Depth of the installation will also be an issue, as cut and fill may affect the water main. Recommend installation of the road/storm sewer along with the water main.

Please see previous applicant letters. The stream buffer is still called-out as 120 feet in width in at least two (2) locations of the PDP.

Waiver request only provided the form. Please see previous applicant letter for specific attachments necessary to process the waiver. An abbreviated report shall be attached to the waiver describing the need for the waiver, locations of the waivers, exhibits, and the impact of the waiver request.

Stormwater report contains an issue that is difficult to reconcile. It still appears that double-counting was done when calculating the allowable release rate for RP-1 (see previous applicant letter). As a final check, the calculated allowable release rate for a particular point should always be less than the existing peak flow to that point. According to Table 2-2, the existing 100 year peak flow for RP-1 is 370 cfs. The calculated allowable peak flow at RP-1 is shown at 377 cfs, 7 cfs over the existing condition. The 10 year event at RP-1 is shown with the same issue, albeit at an even higher difference. It is suspected that double-counting of the raw allowable for subareas may be the issue.

Please see previous applicant letter. The City would like to reserve the right for a variety of underground drainage systems that bisect the site from east to west. As shown, it is still called-out as "to be piped". Recommend removing that particular note on the Utility plansheet, and leaving the other which states "underground drainage system".

Misc.

Make adjustments to street names (Dalton) per Development Services.

The previously submitted elevations did not include the proposed building materials. Additional information regarding the proposed materials will be require prior to public hearings at the Planning Commission and City Council.

Internal access preferred for estate lot. Future use restricted to residential with existing access.

Allowable release rates may have "double-counted" the existing off-site peak flow rates based on a review of the report. Allowable peak flow rates should be calculated as follows: 1) project area (i.e. the area of the project not including off-site contributors) to a point of interest should be multiplied by the respective allowable peak flow rates (i.e., 3, 2, and 0.5 cfs) to obtain the "raw allowable", 2) existing condition off-site drainage area(s) should be assigned a calculated existing peak flow rate for the respective storm events and may be added to the "raw allowable". It appears the off-site drainage areas may have been multiplied times the 3, 2, and 0.5 cfs peak flow rate allowables, thus creating a situaton where the existing peak flow rates from offsite areas is being double-counted. Please check and verify.

Please submit a waiver request for the items listed in the report. The waiver shall be on prescribed form, and include a brief summary report and exhibit(s) describing why the waiver should be granted. Please stress the drainage area number 2 is a "peripheral drainage area" with resultant grading after development being significantly less than existing to the point of interest, and post-development peak flow rates to the point of interest will be significantly less than the pre-developed condition. Stream buffer waiver should also follow same format, and may be included within the same waiver request.

Sheet C3.0 is still showing a 120 foot stream buffer referenced to the centerline in one instance (i.e., the other label was modified and appears correct). The 60 foot buffer is measured from the OHWM on each side of the stream, not the centerline.

A temporary cul-de-sac is required near lot 39.

Revised phasing plan appears to show a long dead end water main in Phase 1. Maximum dead end length is 700 feet. Rough measurements show at least three times this length.

Additional off-site manhole is proposed for sanitary sewer connection. The school district is constructing a public manhole to the north of this proposed manhole, and it is unclear why an additional manhole is being proposed. This proposed location will also require additional easement from the Whitance property to the south, which may further complicate this layout.

It does not appear sanitary sewer was extended to the east plat limits to potentially serve the James A. Reed facility. This was discussed at the applicant meeting, and the response to comments stated this had been shown.

East/west channel shows a proposed pipe system to be designed at a later date. The City would like to reserve the right to revise this as necessary. Please indicate "proposed underground storm drain system".

Misc.

Make adjustments to street names (Dalton) per Development Services.

After additional review it was determined that Dalton Dr. is an existing north/south street in the Newberry subdivision. Please choose a new name for this road.

The proposed project is not subject to the landscaping requirements for street frontage and open yard landscaping found in 8.790, but is subject to sec. 8.870 that established the requirements for buffers/screens between developments of differing land uses adjoining one another.

As this is a planned zoning district. Exterior building elevations are required (previously submitted). Preliminary building elevations of all sides must depict the general style, size and exterior construction materials of the proposed homes. The previously submitted elevations do not include the proposed building materials. The approved elevations will be used to evaluate compliance with the PDP at the time of building permit application for individual homes.

Will the estate lot be included in the HOA?

As this is a single plat, please number the lots 1-251.

The curvilinear nature of some of the streets are kind of problematic in terms of how you have proposed to name them. There are three streets that are a problem as proposed and need to be revised. 1. The street segment in front of Lots 1-8 just needs to be named Greenridge Dr to make it a continuation of the street as it moves south. 2. Timber Creek Dr as a street name needs to end with Lots 92 and 98. A new street name is needed at the knuckle where Lots 93 and 97 are located. 3. 15th Street needs to end at the intersection in front of Lot 48. A new street name is needed to head south starting with Lots 49 and 61.

On sheet C1.0 please provide existing zoning districts of the property to be rezoned as well as the zoning, land use, and ownership of all parcels within 185 feet of the property to be rezoned.

Please show the location of all oil and gas wells, whether active, inactive, or capped. If none are present please add a note stating so and cite your source of information.

To approve the community pool/amenity facilities during this PDP process, please proved preliminary building elevations of all sides depicting the general style, size and exterior construction materials and color schedule of the proposed structures. If this information is not provided a new PDP by separate application will be required for approval.

As the proposed new zoning is planned districts please provide exterior construction materials of the proposed homes.

In the Site Data Table please provide the dwelling units per acre, with and without common area.

As a low impact screening buffer is required along the west and south property lines, please provide a landscaping and buffer plan that includes the information as listed in the ordinance.

All signs must comply with the sign requirements as outlined in the sign section of the ordinance and will be review under separate application.

The location of the proposed monument sign at SE Brownfield Dr/SE Bailey Rd seems it may be problematic. If it is to be located on Tract E it may be in conflict with an existing easement. If it is to be located on lot 1, you will need to establish a sign easement on that lot.

The location of the proposed monument sign at SE Cape Dr/SE Ranson Rd seems it may be problematic. If it is to be located on Tract B it may be in conflict with an existing easement. If it is to be located on lot 1, you will need to establish a sign easement on that lot.

A large portion of the proposed project is located in an existing National Register of Historic Places District, Bailey Family Farm District. As such the National Historic Preservation Act, Section 106 may be applicable to this project or may be applicable to future projects. Section 106 of the National Historic Preservation Act is concerned with Federal undertakings. A Federal undertaking is a project, activity, or program either funded, permitted, licensed, or approved by a Federal Agency. Undertakings may take place either on or off federally controlled property and include new and continuing projects, activities, or programs and any of their elements not previously considered under Section 106. Under Section 106 of the National Historic Preservation Act, federal agencies must consider the effect of their actions on historic properties and provide the federal Advisory Council on Historic Preservation (ACHP) the opportunity to comment on proposed actions. Each (SHPO) plays a critical role in the Section 106 process. As set out in Sections 101(b)(3) and 101(d) of the NHPA, they “consult, advise, and assist” federal agencies in carrying out the agency’s Section 106 responsibilities. Under Section 101(b)(9)(a) of the NHPA, SHPOs have a responsibility to “consult with appropriate Federal agencies . . . on Federal undertakings that may affect historic property.” 36 CFR 800 (Protection of Historic Properties) governs the Section 106 process and outlines how Federal agencies are to consult with SHPOs, THPS, Tribes, NHOs, and other interested parties, identify historic properties, determine whether and how such properties may be affected, and resolve adverse effects. Please contact the Missouri State Historic Preservation Office, (573) 751-7858, to determine if a Section 106 Review is required for this project.

The maximum block length in residential areas is based on land use and zoning district. For the RP-2 district the maximum block length is 640’. SE Greenridge Drive and SE 13th St exceed the maximum by 79’ (719’). A block of this length will require a modification. Please provide a written request and justification for the modification.

"Preliminary Stormwater Management Plan" dated Mar. 5, 2021 is incomplete for the following reasons: 1) missing stream buffer discussion and method used for OHWM delineation, 2) discussion of emergency spillway preliminary design, including freeboard requirements for the 100 year clogged condition/zero available storage event, 3) analysis of the culvert design at Cape Dr. and the east/west stream bisecting the project, including preliminary sizing, culvert type, design storm, etc.

Culvert crossing at soutwest end of project shall be designed to manage the 100 year event, without affecting the calculated 100 year water surface elevation upstream of the culvert. A more frequent storm even may be allowed if the adjacent property grants an inundation easement or other suitable agreement for the area in question. If the inundation easement is provided (or other suitable agreement as determined by Law Dept.), design storm would be based on the collector street standards shown in the Design and Construction Manual, with 100 year overtop low spot (if any) located as specified in the Design and Construction Manual.

Limited grading of detention basin dam within buffer would not necessarily require a waiver. Any other grading, such as shown within a lot, would require a waiver. Recommnend elimination of the encroachment areas other than portions of detention basin dams requiring a waiver.

Points of discharge were not shown for the detention basins. This should be shown, with preliminary energy dissipation measures. We would recommend a more robust energy dissipation measure to be designed for the larger detention basin, and consideration be given for the smaller basin in the southwest. The Federal Highway Administraton has field-tested designs to create a hyraulic jump within the structure for a variety of flow conditions, and this would appear warranted for such a large detention basin.

The preliminary stormwater study did not appear to be set up properly. Terms such as "required peak discharge" was not defined. Only one (1) point of interest is shown as RP-1 in the southwest corner of the project within the stream. Multiple points of interest (where a partcular drainage area converges from sheet flow to concenrated flow) exist on this project both in the existing and proposed condition. These should be shown, and an allowable release rate calculated for each. A comparison should be made for the proposed condtion. Waivers must be discussed within the report where these allowables cannot be met.

Over-detaining in one area, while under-detaining or free release in another is not allowed when intervening property(s) is impacted, unless a waiver is obtained. Intervening property is defined by the City as "property not owned by the developer". Exceptions to this rule would be "peripheral drainage areas", where limited areas are allowed to free-release without detention, provided that the post-developed condition peak flow rate is significantly less than the pre-developed peak flow rate for that particular subarea. Peripheral drainage areas would generally include backyards, and areas adjacent to right of way. This would, however, require a waiver to the Design and Construction Manual.

All stormwater-related waivers to the Design and Construction Manual must be discussed within the body of the report and the conclusions of the report.

Existing condition curve number is shown in the stormwater report as 87. This appears excessively high for the conditions. Off-site contribution to drainage area is shown at 77 which is also high for the conditions.

Recommend providing a more logical sequence within the stormwater report text showing a step by step method for ensuring the Compehensive Control Strategy is met for this project. It appears one area is being free-released with no detention, while others are over-detained to meet the allowable? Also, the term "required peak discharge" is not defined anywhere in the report, and we have never seen such a term used in a stormwater study. The City does not require any particular minimum number for peak discharge, and it is unclear what is meant by this term.

It appears only one point of interest is shown at RP-1 in the southwest corner of the project. While this would be allowed if intervening property was not being crossed, the entire western boundary of the project is adjacent to a the school district property, and is also bounded by the private property to the south, and right of way to the north and east. Additional points of interest, with allowable release rates at each point of interest where stormwater runoff converges to concentrated flow, would appear warranted for this site.

Where backyards and areas near streets are allowed to free-release stormwater without detention, waivers would be supported for what we define as "peripheral drainage areas" in limited situations where additional detention basins are not practical. This would be contingent upon the demonstration that the post-developed condition for these peripheral areas is less then the existing condition due to final grading of the site, and subsequent reduction in drainage area to a particular point of interest.

This site abuts several different intervening properties (i.e., school district to the west, right of way to the north and east, and the private property to the south). It appears only one (1) point of interest was analyzed at the southwest corner of the project, which is not sufficient. Existing conditions topographic map shows more than one point of interest when viewed from the context of intervening property, and these should be shown on the existing conditions drainage map shown within the appendix. Allowables should be calculated for each of the points of interest, based on existing drainage area to the respective point of interest. Some of these points of interest may lie outside the limits of the project, and if so, credit to the allowable release rate would be allowed based on the existing condition for the off site areas. Finally, the proposed peak flows at these points of interest at the respective points of interest are then compared for compliance. As shown, it appears only one (1) point of interest is shown in the southwest corner, and this is not sufficient for this project. There are other points of interest that need evaluation in terms of allowable release rate, not just the southwest corner of the project.

Lot corners at intersections shall be camfered rather than curved. This will accommodate ADA-accessible ramps better in terms of design.

As an informational comment, ADA-accessible ramp geometry shall be changed at certain intersections for the final design. The City no longer allows bi-directional ramps at the apex of the curve. Individual curb ramps shall be provided for each ADA-accessible route across the intersection. Each shall be lined-up with the ADA-accessible route.

Sanitary sewer connection near the southwest corner of the project conflicts with the new culvert to be installed. Sanitary sewer shall be installed outside the limits of the culvert and associated embankment.

Sanitary sewer service to the estate lot shown in the northeast corner of the project does not appear to be served by public sanitary sewer. This shall be required, either by a public line, public easement, private easement, or private line. Discussion to follow at applicant meeting.

The area encompassed by lots 31 through lot 51 do not appear to have sufficient drainage in the rear. Recommend additional drainage structure such as a field inlet(s) in rear of lot to capture stormwater, as well as swale to capture and divert stormwater.

Recommend a re-evaluation of other blocks that may need additional rear yard swales or diversion berms.

100 year water surface elevation within detention basins must be shown in numeric and graphic format, preferably on the grading plan. This should also include the clogged/zero available storage condition. This line should be a minimum of 20 feet from any property line, building, or right of way line.

Detention basin dam sides are allowed to encroach within the stream buffer without a waiver subject to the following conditions: 1) dam side only, not including any portion devoted to storage or the top of the dam, 2) dam to be grassed, and left to its natural ground cover.

Sanitary sewer is shown being installed overland in the first phase for a considerable distance across unplatted property (see the southwest portion, where sanitary sewer lines are 10 to 12 inches - Line A). This overland sanitary sewer would be installed in areas that are platted in the 3rd phase, which could be years in the future. This issue shall be discussed at the applicant meeting, since overland sanitary sewers installed in unplatted areas, where depth issues may occur either before the 3rd phase, or after the 3rd phase occurs, as well as maintenance issues due to installation of these lines in overland areas, may be prohibited by the City.

Sanitary sewer is shown crossing beneath a culvert in Tract A. This is problematic for the City in terms of maintenance, and an alternate route shall be established across the stream bisecting the project from east to west. This shall be discussed at the applicant meeting.

Stream buffer call-out for the stream bisecting the project in the east/west direction appears incorrect. The buffer is measured from the OHWM, not the centerline of the stream. However, please check the scale. It appears the dimension is incorrect due to scale issues (we measured 132 feet versus the 120 foot call-out).

It is possible that extension of sanitary sewer to the eastern plat boundary is required, at a suitable location for a future connection (i.e., based on elevations). This requirement shall be discussed at the applicant meeting, since the property to the east is outside City limits.

10' Shared Use Path required along Bailey and along Ranson Road in compliance with Greenway Master Plan.

MoDOT comments on Traffic Study Pending.

Can the Estate Lot be provided access from the local residential street (and exisitng access on Bailey Removed)? In consideration of the AMC and potential signal queuing on Bailey, access is preferred internally to the subdivision.

Misc.

Make adjustments to street names per Development Services.