New York State Department of Transportation



PIN xxxx.xx

PROJECT DESCRIPTION

DRAINAGE REPORT

FOR DOT PROJECTS

Prepared in Accordance With

Chapter 8 of the NYSDOT Highway Design Manual (HDM)

Prepared By:

[Regional Design Group] OR [Consulting Firm]

[NYSDOT Region] or [Consultant Location]

Date (Month and Year)

|PLACE P.E. STAMP |

Note: It is a violation of law for any person, unless they are acting under the direction of a licensed professional engineer, architect, landscape architect, or land surveyor, to alter an item in any way. If an item bearing the stamp of a licensed professional is altered, the altering engineer, architect, landscape architect, or land surveyor shall stamp the document and include the notation "altered by" followed by their signature, the date of such alteration, and a specific description of the alteration.

Table of Contents:

Cover………………..………………………………………………………...………………..………….1

Table of Contents….……………………………………………………..……….………………..…….2

Summary of Drainage Impacts…...……………………………………..……….………….................3

Background………………………………………………………………………………………….…...3

Hydrology…………………………………………………………………….….……………….……….5

Open Channels..…………………………………………………………….…………………..……….6

Culverts………...………………………………………………………………..………….…………….6

Storm Drainage Conveyance System(s)………………………………………………..……………..7

Erosion & Sediment Control & Stormwater Management………………...…………..……………..8

Special Considerations.....………………………………….………………...…………..……………..8

References…...……….....………………………………….………………................………………...9

Appendices:

- Appendix A - X

Highway drainage is an important consideration in the design of many projects. The term drainage is defined in several different ways, including the process of removing surplus groundwater or surface waters by artificial means, the manner in which the waters of an area are removed, and the area from which waters are drained. A project may alter the existing drainage. When this occurs, drainage features should be provided which protect the highway, adjacent landowners, and the traveling public from water, while maintaining water quality and protecting other environmental resources.

Background:

Preliminary research should take place before conducting the first field trip in order to make the trip more productive:

1. Obtain available topographic information, including USGS quadrangles, county or municipal topographic maps or other recent surveys. Outline the drainage patterns and areas on a contour map.

2. Determine soil characteristics of each drainage area for the project. This information may be obtained from the NRCS County Soil Survey or from the Regional Geotechnical Engineer.

3. Check Highway Record Plans for the area. They can be used as a guide to size proposed structures.

Project Soils:

See Appendix D for the NRCS soils map within the project area. The following soil types and hydrologic groups are present within the project drainage area:

TABLE 1 – SOIL TYPE

|Soil Symbol, Name, % Slope |Hydrologic Group |Texture |Character |Erosion Hazard |% within |

|Range |(HSG) | | |Potential |project drainage area |

|DeA, Deerfield complex, 3 |B |Loamy fine |Moderately well |*Slight |27.5% |

|to 8 percent slopes | |sand |drained | | |

|Ud, Udipsamments, dredged |A |Loamy sand or |Excessively drained |*Slight to |53.3% |

| | |sand | |moderate | |

|WnB, Windsor Complex, 3 to |A |Loamy sand |Excessively drained |*Slight |12.1% |

|8 percent slopes | | | | | |

|WnD, Windsor Complex, 15 to|A |Loamy sand |Excessively drained |*Severe |7.1% |

|25 percent slopes | | | | | |

• Number of different soil series and hydrologic soil groups

• Brief description of each series

EXAMPLE: There are three different soil series and two different hydrologic soil groups within the project drainage area. The largest soil series within the project area is the Udipsamments soil, which is made up of material dredged from Saratoga Lake. It is typically loamy sand or sand with layers of silty material or gravel at varying depths. Depth to bedrock is greater than 60 inches and depth to seasonal groundwater is more than 6 feet. The Deerfield complex (DeA) makes up the next largest portion of the area of disturbance. It is a loamy fine sand formed on glacial outwash plains and terraces. It is very deep, moderately well drained and the topography within this series is generally undulating. Depth to bedrock is greater than 60 inches and depth to water table is between 1.5 and 3 feet. The Windsor complex contains the remaining two soil types, WnB and WnD with the first characterized by undulating terrain and the second hilly terrain. Both subseries are loamy sand, excessively drained and formed on glacial outwash plains, kames and terraces. Depth to bedrock is greater than 60 inches and depth to seasonal groundwater is more than 6 feet.

*(The erosion hazard indicated in the table above was originally a consideration for the forestry industry, and indicates the susceptibility of a particular soil to erode in a fully exposed condition. The Department is utilizing this information to indicate areas of the project which may be of critical concern to the contractor during storm events).

Construction History:

• The existing drainage system(s) were constructed in [enter year(s)]

• Project Dnumber(s) for previous State contracts [list Dnumber(s)]

• The existing drainage facilities are [closed drainage, open ditches with driveway pipes, curb and gutter sections]. The pipes are predominately made from [HDPE, corrugated steel, reinforced concrete, PVC]

EXAMPLE: The existing drainage conveyance systems appear to have been constructed under various state contracts beginning in 1912, most likely by the Village of Lowville. The drainage system began to be reconstructed and replaced beginning north of the project limits in 1960 under state contract FARC 60-30. This project consisted of collecting street runoff from the northern village limits around Summitt Ave and conveying the drainage south along State Street into the project limits by installing a single 36” RCP discharging at the northeast quadrant of the Mill Creek bridge. Record plans do not indicate that current drainage from South State Street is connected to this system; however, field investigation of each manhole in the project limit revealed that the existing drainage from lower Dayan Street and South Street are connected to the system. South of Mill Creek, from the 12/26 intersection to the Mill Creek bridge, drainage consists of a closed storm drainage system that was partially reconstructed with new corrugated plastic pipe and precast drainage structures under State contract D253216 in 1990. The majority of Dayan Street utilizes the original drainage system from around 1912. In 1973 under state contract FARC 74-56, the closed drainage system from approximately 24+260 to 24+380 was replaced with a new corrugated steel pipe and drainage structures. In 2001, under County of Lewis PIN 7752.25, Cascade Ave over Mill Creek, the drainage system along Cascade Ave was reconstructed with SICPP and precast structures.

Field Observations/ Research:

After the preliminary research has been completed, and preliminary flow rates calculated, the initial field trip should be taken. (Be sure to bring a camera, take lots of pictures, and always try to include a person or other item of known size in the picture to act as a visual scale.) The main items to be investigated are:

1. Drainage patterns and drainage areas.

2. Land use.

3. Soil types.

4. Existing and previous flood conditions.

5. Location of natural and man-made detention features.

• Field collected data [verified OR exhibited discrepancies] with the record plans.

• Ongoing drainage problems [were discovered OR were confirmed not to exist] as a result of outreach to the local DPW or nearby property owners.

• Recent improvements [were discovered OR were not found] which may not be accounted for in the survey information.

• Include photographs of special areas of interest.

• Existing drainage features [will be retained and connected to proposed features OR will not be affected by proposed features]. The methods used to connect existing and proposed drainage are [explain].

EXAMPLE: On 6-5-09 a visual inspection was conducted. Runoff from approximately the intersection of SR 14/CR 72 is collected in roadside ditches and directed to the south. Where driveways cross the ditch, 18” corrugated metal pipes carry runoff. Most of the driveway culverts are 25%-50% clogged. Pipes that are clear of debris show deterioration and rusty perforated inverts.

The ditch has been filled in and a 24” RCP installed at the Yankee One Dollar store location. Two drainage structures were installed at the edge of their parking lot which connect into the ditch south of the parking lot via 12” SICPP.

Discussions with the NYSDOT Seneca county residency have not brought attention to any significant pre-existing drainage problems noted by maintenance forces or history of public complaint. During the field inspection some residents approached the inspector and indicated that the roadside ditches are generally full of standing water. They would like them regraded to drain. The residents did not recall any history of the ditches overflowing onto their property.

Hydrology:

Several methods for determining flow rates are listed in items 1 through 4 below. Methods 1 and 2 are based upon rainfall effects and do not consider snowmelt. In some areas, runoff from snowmelt will regularly exceed peak events due to rainfall. Each flow rate determination method is unique. Users should be familiar with each method, and be able to select the most appropriate method for each location and situation.

Recommended methods include:

1. Rational Method. Computes a peak discharge.

2. Modified Soil Cover Complex Method ("Urban Hydrology for Small Watersheds", NRCS TR-55, is the basis for this method). Computes a peak discharge directly using a formula and by plotting a hydrograph.

3. Regression Equations. Computes a peak discharge.

4. Historical Data.

The design flood frequencies provided in Table 8-2 are recommended for use with the Rational Method, the Modified Soil Cover Complex Method, and the regression equations. The design flood frequency is the recurrence interval that is expected to be accommodated without exceeding the design criteria for the open channel, culvert, or storm drainage system.

[pic]

1. The values in this table are typical. The selected value for a project should be based upon an assessment of

the likely damage to the highway and adjacent landowners from a given flow and the costs of the drainage

facility. Note: 100-year requirements must be checked if the proposed highway is in an established

regulatory floodway or floodplain.

2. The check flow, used to assess the performance of the facility, should be the 100 year storm event.

3. Relocated natural channels should have the same flow characteristics (geometrics and slope) as the

existing channel and should be provided with a lining having roughness characteristics similar to the existing

channel.

4. Including lining material.

5. As per 23CFR650A, and Table 1-1 of HDS 2, a 50-year frequency shall be used for design at the following

locations where no overflow relief is available:

a. sag vertical curves connecting negative and positive grades.

b. other locations such as underpasses, depressed roadways, etc.

6. A design flood frequency of 10 or 25 years is acceptable if documented in the Design Approval Document,

and when identified after design approval, in the drainage report. A design flood frequency of 10 or 25 years

should be used in the design of driveway culverts and similar structures.

7. Use a 25-year frequency at the following locations where no overflow relief is available:

a. sag vertical curves connecting negative and positive grades.

b. other locations such as underpasses, depressed roadways, etc.

• The watershed areas were delineated using [DTM’s, DEM’s, contours, field inspection]. See Appendix C for Subcatchment Maps.

• The hydrologic analysis method used is [TR-55, Rational Method, Regression Equations, Historical Data]

• The design storm from NYSDOT Highway Manual Chapter 8, Table 8-2 used for analysis is [Explain]

• The rainfall information selected (IDF curve) is [Explain]. The reasoning for choosing the selected rainfall information is [Explain].

• The computer software used in the analysis is [Explain].

EXAMPLE: Drainage basins were delineated utilizing a combination of photogrammetric survey, USGS topographic maps, and site reconnaissance. The contributing drainage area varies within the project, the northern portion adjacent to the SR 14 is predominantly moderate slope residential neighborhoods with 1 acre lots. The southern portion of the drainage area is flatter with some commercial/industrial development. Because of the size of all contributing basins, smaller than 80 hectares (197 acres), the rational method was used to develop peak discharge conditions (ref HDM 8.3.2.4)

Contributing drainage basins to each inlet or culvert opening were delineated with the use of survey data available and USGS topographic mapping when outside of survey limits. Runoff coefficients used are consistent with HDM Table 8-3, times of concentration were computed, and in most cases the minimum of 5 minutes was used (HDM 8.3.2.4). A 10-year design storm frequency for principal arterials was selected in accordance with HDM Table 8-2. The closest IDF curve available for the area was the Seneca County, NY curve developed by the NYSDOT main office in Albany utilizing HEC 12 software (refer to appendix A). Bentley Storm and Sanitary computer software was used to develop peak flows.

Open Channels:

The open channels that will be affected by the project are located [Explain].

• The scope of work includes [regrading existing channels, converting open channels to closed drainage, lining existing channels with stone fill, installing rolled erosion control products]

• Provide a brief analysis of the capacity and expected flow in the channels.

• Channels to be stone lined will use [fine, light, medium, heavy] size stone based on the expected channel velocity of [Explain].

• Channels to be lined with RECP’s will use [select appropriate item from spec section 209-3.10]

EXAMPLE: Drainage will be maintained in one open channel system located at approximately 24+220 along Dayan Street at the Northern end of the project limits. The existing cross-culvert will be replaced in-kind, the existing channel will be cleared of excess debris and stone fill will be installed to prevent erosion within the channel.

Within the project limits two additional discharge points to open channels are being eliminated at 24+390 & 24+715.

Culverts:

Identify any culverts that will be affected by the project (rehabbed or replaced).

• The scope of work includes [cleaning existing culverts, lining existing culverts to extend their service life, replacing existing culverts, installing culverts in new locations].

• Provide a brief analysis of the capacity and expected flow in the culverts.

• The inlet and outlet treatments will include [galvanized end sections, concrete headwalls, stone aprons].

• The software used to size culverts is [HY-8, HydroCADD, TR-55].The software output files are provided in appendix B.

EXAMPLE: The portion of the culvert under the state highway, located at Sta. 24+220 will be replace, beginning at the drainage manhole, downstream to the permanent easement discharge channel ( refer to open channel discussion for treatment). The proposed replacement will consist of a new precast manhole unit and a 24” RCP with a precast flared end section. No hydrologic or hydraulic calculations have been performed since the pipe size will be replicated in kind and the upstream controlling pipe will not be replaced.

Storm Drainage Conveyance System(s):

• Briefly describe existing and proposed storm drainage systems. Establish closed drainage limits and streets affected by construction.

EXAMPLE: The entire project, currently and as proposed, drains to a closed storm drainage conveyance system. Since the project does not include either interstate or freeway, inlets have been located and spaced to ensure that runoff will not spread beyond one half the width of the right most travel lane (HDM 8.7.4.4 C). At the request of the Lewis County Resident Engineer, a grate inlet (curb and grate) will be used, in place of the standard combination inlet (curb opening and grate). The selected pipe material for overall lowest cost (HDM 8.6.2.4) is a smooth interior corrugated polyethylene pipe (SICPP), where sufficient height of cover below the subgrade layer exists, in areas where sufficient cover does not exist, reinforced concrete pipe (RCP) will be specified.

For each existing and/or proposed stormwater drainage network address the following items:

• The limits of the [existing/proposed] network are [street names, stations, landmarks as appropriate].

• List structures to either remain, be rehabilitated, or replaced.

• Include pipe rehabilitation techniques and new proposed pipe materials.

• Discuss hydrologic analysis of system and any areas of concern.

• To build the proposed network, the work zone will have to include phases to allow installation of the proposed drainage features. The sequence of construction is [Explain].

• The analysis software output file is attached in Appendix B.

[pic]

Figure 1: Example Stormwater Reconstruction Areas and Discharge Locations

Network A:

The existing storm drainage system at the project beginning in the resurfacing area from the 12/26 intersection north to Stowe/River Streets (Sta. 34+960 to 35+467) will be retained since no drainage deficiencies have been noted. Drainage structures that are deteriorated or in need of cleaning will be be returned to original condition. No analysis was performed on drainage elements within this section, since drainage patterns will remain relatively consistent to preconstruction conditions, and there is no known history of flooding. A partial new storm drainage system is proposed beginning at the southern reconstruction limits (Sta. 35+467) on South State Street proceeding North to the Mill Creek bridge (Sta. 35+505). This system will consist of new precast drainage structures with frame and grate placed along the curbline and new SICPP up to, but not including, the outlet pipe to the stream. This segment is not proposed to be replaced because it is in good condition and could involve structural, and potentially, foundation impacts to the bridge and adjacent building. Structure size, frequency and placement were checked with Storm and Sanitary software with a max spread limit of ½ the right most travel lane. Structures DN# 1, 2, 4, and 5 exceeded the spread limit, due to the pavement cross slope and proximity to the reconstruction limit, which limits the ability to place additional inlets upstream to intercept the flow. Pipe sizes were also verified for expected capacity. Refer to Appendix B for network analysis of the system.

Network B:

A partial new storm drainage system is proposed beginning at the north abutment of the Mill Creek Bridge (Sta. 35+526) on South State Street proceeding North to the end reconstruction limit (Sta. 35+880) on North State Street. The system then continues north up Dayan Street to Sta. 25+058 collecting surface flow from south of Cascade Ave. The partially new system will consist of new precast drainage structures with frame and grate placed along the curbline. Within the reconstruction area, drainage structures were placed intermittently and checked with storm and sanitary software for a spread limit of ½ the right most travel lane and the full shoulder or parking lane where they exist. DN# 12, 22, 31, 34, 35 and 36 exceeded the spread limit, due to the pavement cross slope and proximity to the reconstruction limit which limits the ability to place additional inlets upstream to intercept the flow. The drainage conveyance system consists of new SICPP, where cover permits. The section along Dayan Street begins with a connection to an existing drainage pipe believed to be entering at approximately 25+060 left (refer to hand sketched detail in Appendix B, source unknown) which carries flow from behind the north homes on upper Dayan Street to the Legion parking lot and then under the bank parking lot into the existing system the size is believed to be approximately 12” in diameter. From that point, the entire system is being replaced to the State Street intersection. Beginning at the State Street intersection the system is a combination of new SICPP laterals connected to an existing 36” RCP trunk line at existing manholes. The existing RCP drainage trunk line runs through the entire reconstruction limit along State Street to Clinton Street/West State Street Intersection approximately 0.34 miles beyond the projects reconstruction limits on State Street. This RCP trunk line was constructed in 1960 under FARC 60-30, was inspected and determined to be in good condition. Because the existing trunk line is in good condition with considerable remaining service life, has no known drainage deficiencies and would be very costly to replace, it was determined that the line would continue to act as a trunk line to the Mill Creek discharge and the replaced system would consisted of laterals to the existing manholes. The 36” trunk line was not analyzed for capacity because a majority of the flow was outside the project limits and no significant change in runoff flowing to the system is proposed. The existing RCP drainage trunk line is being replaced from DN# 13 (Sta. 35+550) to provide an increased size from 36” to 42”. This is to provide capacity for additional flow that is being directed from station 35+650 to 35+550 right side, into the system that is currently discharging from a 12” steel pipe in the north abutment of the Mill Creek bridge that is being eliminated. Refer to Appendix B for network analysis of the system.

Network C:

An entirely new drainage system is being proposed from State Street east on Shady Ave to the end reconstruction limit (Sta. 0+123). The system collects runoff from State Street to a high point in the highway approximately 370 feet beyond the reconstruction limits on Shady Ave. The proposed system consists of combination inlets with both grate/curb capacity. Within the reconstruction area drainage structures were checked with storm and sanitary software for a spread limit of ½ the right most travel lane and the full shoulder or parking lane where they exists. DN# 86 and 89 exceeded the spread limit, due to the pavement cross slope and proximity to the reconstruction limit which limits the ability to place additional inlets upstream to intercept the flow. The proposed system connects to the existing 3’ x 4’ box culvert that flows beneath the adjacent building south to Mill Creek. Refer to Appendix B for network analysis of the system.

Network D:

An entirely new drainage system is being proposed from the village line (sta. 24+260) south to Cascade Ave and down to the bridge over Mill Creek on Cascade Ave. The system collects roadside runoff between the curbs from a highpoint at Sta. 24+025 down grade to Cascade Ave. and continuing up to and including the bridge over Mill Creek. The proposed system intercepts an existing box culvert at Sta. 24+380, which currently crosses and discharges on the south side of Dayan Street. For this reason, the trunk line is slightly oversized (30”) to better handle larger flow rates than are expected from the drainage analysis. A second outfall at approximately Sta. 24+715, is being eliminated and carried to the discharge point on Cascade Ave. The existing outfalls are in close proximity to residential structures and are difficult to maintain. The proposed system will consist of new precast drainage structures with frame and grate placed along the curbline. Within the reconstruction area drainage structures were checked with storm and sanitary software for a spread limit of ½ the right most travel lane and the full shoulder or parking lane where they exists. DN# 47, 56, 57, 59, 69 and 77B exceeded the spread limit, due to the pavement cross slope and proximity to reconstruction limit which limits the ability to place additional inlets upstream to intercept the flow. The drainage conveyance system consists of new SICPP, where cover permits. Refer to Appendix B for network analysis of the system.

Summary of Drainage:

Fill out the information in Table 2 for each Design Point for the project and provide any additional pertinent discussion of drainage flows.

TABLE 2 - STORMWATER SUMMARY

|Storm Event |Pre–Project Runoff (cfs) |Post–Project Runoff (cfs) |

|Design Point 1 |

|5 |x.xx |x.xx |

|10 |x.xx |x.xx |

|25 |x.xx |x.xx |

|50 |x.xx |x.xx |

Erosion & Sediment Control & Stormwater Management:

Erosion and sediment control is any temporary or permanent measure taken to reduce erosion, control siltation and sedimentation, and ensure that sediment-laden water or wind does not leave the site. Guidelines for providing erosion and sediment control are discussed in Section 8.8.2.1. The E&SC plan resulting from these guidelines is discussed in Section NYSDOT HDM 8.8.2.2.

Note: The guidance in Sections 8.8.2.1 and 8.8.2.2 is based on Attachment 4.3.A of EPM Chapter 4.3

The following is recommended guidance:

1. Preserve the existing vegetative groundcover on the project site as much as possible to protect the soil surface and limit erosion.

2. Sediment control practices/measures, where necessary, should be designed to protect the natural character of rivers, streams, lakes, coastal waters, wetlands, or other waterbodies on-site and minimize erosion and sedimentation off-site from the start of land disturbance activities to establishment of permanent stabilization.

a. The off-site impacts of erosion and sedimentation related to land clearing, grading, and construction activities should not be any greater during and following land disturbance activities than under pre-development conditions.

b. Pursuant to Part 700 et seq. of Title 6, Chapter X of NYCRR:

1. Toxic and other deleterious substances shall not be discharged in amounts that will adversely affect the taste, color or odor thereof, or impair the waters of the state for their best (classified) usages,

2. Suspended, colloidal, and settleable solids shall not be discharged in amounts that causes substantial visible contrast to natural conditions, or causes deposition or impairs the waters for their best (classified) usages.

The project will fall under one of the following conditions. Include one of the following statements:

A. The project will be subject to NYSDEC general permit GP-0-10-001, which covers State Pollution Discharge Elimination Systems (SPDES).  Because of this the project will be obligated to have a Stormwater Pollution Prevention Plan (SWPPP). For a detailed description of proposed temporary erosion and sediment control and permanent water treatment plans and practices please refer to the projects SWPPP. [For project disturbances > 1 acre]

OR

B. The project will follow the Erosion & Sediment Control provided in NYSDOT Highway Design Manual, Chapter 8.2 [For project disturbances < 1 acre]

Refer to the Erosion & Sediment Control plans for proposed temporary on-site Erosion Control measures.

Special Considerations:

• Briefly discuss any special environmental concerns (wetlands, stream temperature considerations, critical habitat, etc.) which influenced the drainage design.

EXAMPLE: The presence of wetlands on the north side of the proposed driveway between SR 14 and the proposed parking area influenced the site grading and required drainage to be directed to the south side of the proposed driveway.

References:

Highway Design Manual, Chapter 8, NYSDOT, 50 Wolf Road, Albany, NY 12232.



Standard Specifications, Construction and Materials, NYSDOT, 50 Wolf Road, Albany, NY 12232.



Hydraulic Engineering Circular No. 22, 2nd Edition, Urban Drainage Design Manual, August 2001, FHWA

Environmental Assessment Form [Long Form] OR [Short Form]

Record Plans: List appropriate Contract Plan set Dnumbers.

APPENDIX A

RAINFALL INFORMATION

IDF TABLE

APPENDIX B

NETWORK ANALYSIS

(Provide separate analysis for each independent storm drainage system or culvert)

APPENDIX C

SUBCATCHMENT MAPS

DRAINAGE PLANS

DETAILS

DRAINAGE NOTES

APPENDIX D

NRCS SOIL MAP

Guidance on using this shell:

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• UNDERLINED BLUE TEXT is hyperlinks to web pages.

• Light blue text provides guidance directly from the NYSDOT Highway Design Manual

• ITALIC TEXT shows example text to assist the writer in preparing the report. It should be deleted before finalizing the report.

• BLACK REGULAR text is to be included in the report (after selecting appropriate choices and deleting the italic example text)

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DISCHARGE C

DN# 89

STA. SH 0+075 RT

DISCHARGE D

DN# 85

STA. CA 0+201 LT

DISCHARGE A

DN# 6

STA. 35+505 RT

DISCHARGE B

DN# 7

STA. 35+530 LT

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