HomeMy WebLinkAbout20230378 Washington Land Disturbance Engineering Comments
City of Saratoga Springs
OFFICE OF CITY ENGINEER
CITY HALL
474 Broadway, Room 10
Saratoga Springs, New York 12866
_____________________
Telephone 518-587-3550
Fax 518-580-9480
www.saratoga-springs.org
Comments/Description of Land Development Project
329 Washington Street
Planning Board (PB) # 20230378
All,
Below please find a description from questions and comments asked of engineering staff from
the planning board workshop, DPW’s overall review, and some questions/comments from the
public to go over the PB 20230378, 239 Washington Street Land Development. This included
review of the Stormwater Pollution Prevention Plan (SWPPP) and plans, review and description
of submitted materials along with question and response from the engineers, Labella, who
created said SWPPP and plans.
It is my goal to summarize the land development plans, SWPPP, and explain what is shown
from an engineering perspective to the planning board. My responses are from my review and
research along with Labella’s plans, SWPPP, and response to my initial questions. I have also
placed a quick notes conclusion page at the end of my review description. I also had a meeting
with Labella on Monday 10/7/24 for some additional questions and answers before finalizing this
summarization.
This land development project is a proposed grading project that includes filling in two (2) non-
jurisdictional wetlands on the property. Definition of a non-jurisdictional wetland means a
wetland that is not subject to regulation by federal law but is a water of the State and may be
pursuant to State law. Per the application, NYSDEC submitted a letter March 13, 2024
determining “that there are no DEC regulated wetlands or associated adjacent areas on the
parcel.” It also states “that changes to Article 24 regulations are expected in January of 2025.
Information regarding wetland mapping and jurisdictional determinations may be subject to
change when new regulations go into effect.” Letters are within the application of this project.
The SWPPP includes soil and groundwater description, receiving water bodies, wetlands
description of depiction and size, pre and post development watershed conditions, and
descriptions of analysis, including sub-catchment areas and points used within Hydro CAD, to
name a few key items to aid in explaining the project.
Existing Conditions of the site include the two non-jurisdictional wetlands (wetlands are 2.01
acres on the total 8.90-acre site or roughly 22% of the site). The pre-development conditions per
the SWPPP “…project site is covered predominately by woods and developed impervious
surface (pavement and buildings).” The analysis done within the SWPPP looks at existing
DEBORAH M. LABRECHE, P.E.
CITY ENGINEER
MATT ZENO
ASSISTANT CITY ENGINEER
SCOTT PALMER
SURVEYOR
JAMES SALAWAY
PRINCIPAL ENGINEER TECH
CRISTINA HASENSTEIN
SENIOR ENGINEER TECH
ZACHARY MADDING
SENIOR ENGINEER TECH
JAMES BUNKER
ENGINEER TECH
KATE HALLIDAY
ADMINISTRATIVE ASSISTANT
drainage patterns, soil types, ground cover to remain, planned site development, site grading,
and stormwater management facilities proposed. The analysis follows typical standards within
the industry.
Soil data was obtained using the US Department of Agriculture (USDA) Web Soil Survey online
services. Using this data source is a typical way to get a general idea of what soils are present
on site. This survey showed that three separate soils can be found on this site, they include
Deerfield loamy fine sand (DeA) with 0-3% slopes, Deerfield loamy fine sand (DeB) with 3-8%
slopes, and Windsor loamy sand (WnC) with 8-15% slopes. All three soil types are found to be
in the hydrologic soil group A, which indicates “soils having high infiltration rates and low runoff
potential when thoroughly wet. These soils consist mainly of deep, well drained to excessively
drained sands of gravelly sands. These soils have a moderate rate of water transmission.”
(From SWPPP). Basically, these soils can take on water from the surface very well and will
allow water to convey moderately well once soils are 100% saturated.
It is known by Planning Board staff and DPW staff that a storm water project happened back
around 2003-2005 on Outlook Ave, adjacent to this project location. During the project, a lot of
shallow rock was found and removed to install this storm water collection system. It is also
known that the homes in this area have sump pumps that expel water typically to the existing
storm water collection system or out into the collection area easement to the 18” HDPE inlet
pipe. Labella stated that they used the existing grade as the water elevation for their
calculations due to the areas being wetlands. This is a conservative approach as in most cases
you would look at the water level being closer to bedrock. I had initially asked about a Geotech
report or even a test pit to make sure rock isn’t too shallow. However, because of this
conservative approach, by assuming the water is at grade it doesn’t matter where the rock is
found as water level is the same as existing grade for all calculations. Therefore, I am ok with no
Geotech report or test pit. Future site plan development would need some type of Geotech
report or bore logs, some type of soil information greater than what is provided in this report.
The SWPPP states the existing receiving water bodies taking this water from this parcel is the
Geyser Brook, which is classified as a NYSDEC class C water course, which is not included in
the list of impaired waters found in Appendix E of GP-0-20-001. In saying that, I let Labella know
that the stormwater that connects to the 18” inlet pipe on Outlook Ave actually runs through the
City storm system and outlets out of the Village Brook storm water collection system and
eventually turns into Spring Run. For class water body courses, if the water body is class C (T
or TS) or greater (B, A, AA,) then other storm water procedures have to be followed. This is not
the case for this project as it is only classified as a C with no designation of T or TS (which
mean the water body supports the trout population). I did double check the DEC mapper and
confirmed Spring Run is also a class C water body, see attached.
The total area to be disturbed is 6.20+/- acres of the total 14.1+/- acres of the catchment area.
This catchment area was split into sub-catchment areas to model within Hydro CAD for analysis
purposes. A sub-catchment area is an area of land within the full catchment area that takes on a
certain amount of storm water per elevations, soil infiltration, and development within the area.
These sub-catchment areas or points are then connected and analyzed to see how much
stormwater is flowing to the final design point. The final design point in this case is the 18”
HDPE pipe that sends the water into the existing storm water collection system on Outlook Ave.
Note that this was the pre-existing development design point as well as the post development
design point. I will also point out that this project was broken out into 2 sequences, one being
1.75 acres and the other being 4.45 acres. Labella explains that, “...the project staying under
five (5) acres of disturbance during construction and that the site contractor must temporarily or
permanently stabilize as they go rather than have all area disturbed at once. This is due to the
project not pursuing a five (5) acre waiver.”
The catchment area includes most of 329 Washington parcel along with some areas along West
Ave, Outlook Ave, and Washington Ave. This can be found in the mapping attached as well as
within the SWPPP, showing pre and post development catchment area flow. This post
development catchment area includes grading the site to have flows caught within the existing
parcel and convey the flows over to the north east corner of the property to a proposed graded
pond area. This pond area is graded or dug down to just below 318’ in elevation. When a storm
event occurs, the pond will fill and eventually reach the overflow elevation of 323.75’ flowing
over this elevation point within the proposed grading of the parcel and flow into the design point
of the existing storm water collection system point at elevation 319.1’ (the 18” HDPE inlet pipe).
The pond will then hold water until the level goes below that 323.75 point. Then you will have
standing water for a period of time as it infiltrates back into the type A soils. Below, please see a
snippet of the SWPPP explaining in better detail the areas they chose for the storm water
analysis.
The data, in which I am showing the 24-hour, 100-year storm event from the SWPPP as an
example, shows the following graphs stating total storage along with how long it will take to
drain within the system or drainage rates. These are attached to this letter. The post
development shows a small increase in storage within the pond in comparison to the storage of
the wetlands that are existing. It also shows a decrease in the discharge rate of water in cubic
feet per second (cfs). The decrease goes from 1.39 cfs to 1.03 post development for a 100-year
24-hour storm event. Discharge rate is the maximum rate at which water passes a given point
during or after a rainfall event. See below for an image of the table within the SWPPP. This is
typical design standards per NYSDEC, which designs up to a 100 year
storm.
Conclusions from my review and wrap up of this write up:
1. Project is a land development project that is filling in non-jurisdictional wetlands.
2. There are no connections with culverts under West Ave, confirmed by record drawings
from DOT.
Environmental Resource Mapper
The coordinates of the point you clicked on are:
UTM 18 Eas ng: 600290.8537620911 Northing: 4771377.768369085
Longitude/La tude Longitude: -73.76780184418021 La tude: 43.088493962981495
The approximate address of the point you clicked on is:
Saratoga Springs, New York
County: Saratoga
City: Saratoga Springs
USGS Quad: SARATOGA SPRINGS
Waterbody Classifica ons for Rivers/Streams
Regula on: 941-130
Standard: C
Classifica on: C
303D River and Stream Construc on
Waterbody Name: Tribs to Lake Lonely
PWL ID: 1101-0001
Basin: Upper Hudson River
Descrip on: total length of selected tribs to lake
Waterbody Name: Tribs to Lake Lonely
PWL ID: 1101-0001
10/7/24, 2:40 PM Environmental Resource Mapper
1/2
Basin: Upper Hudson River
Descrip on: total length of selected tribs to lake
State Regulated Freshwater Wetlands
ID: S-39
Class: 3
Size (Acres): 15.6
Na onal Wetands Inventory
A ribute: PFO1/SS1E
Type: Freshwater Forested/Shrub Wetland
Acres: 9.511433669022093
For more informa on about the Na onal Wetands Inventory wetlands visit h p://www.fws.gov/wetlands/
If your project or ac on is within or near an area with a rare animal, a permit may be required if the species is listed as
endangered or threatened and the department determines the ac on may be harmful to the species or its habitat.
If your project or ac on is within or near an area with rare plants and/or significant natural communi es, the
environmental impacts may need to be addressed.
The presence of a unique geological feature or landform near a project, unto itself, does not trigger a requirement for a
NYS DEC permit. Readers are advised, however, that there is the chance that a unique feature may also show in another
data layer (ie. a wetland) and thus be subject to permit jurisdic on.
Please refer to the "Need a Permit?" tab for permit informa on or other authoriza ons regarding these natural resources.
Disclaimer: If you are considering a project or ac on in, or near, a wetland or a stream, a NYS DEC permit may be required.
The Environmental Resources Mapper does not show all natural resources which are regulated by NYS DEC, and for which
permits from NYS DEC are required. For example, Regulated Tidal Wetlands, and Wild, Scenic, and Recrea onal Rivers, are
currently not included on the maps.
Print Preview
10/7/24, 2:40 PM Environmental Resource Mapper
2/2
Outlook
Fw: [Ext] Re: 239 Washington
From James Salaway <James.Salaway@saratoga-springs.org>
Date Thu 10/3/2024 4:55 PM
To Susan Barden <Susan.Barden@saratoga-springs.org>
2 attachments (3 MB)
Photolog2_MohrPhrag.pdf; Att2_2002_4_30_NoNYSDECJDLTR.pdf;
See responses from Labella.
Thanks,
James
From: Drury, Sara <sdrury@LaBellaPC.com>
Sent: Thursday, October 3, 2024 4:24 PM
To: James Salaway <James.Salaway@saratoga-springs.org>
Cc: Farrell, Sean <sfarrell@LaBellaPC.com>; Rohrmeier, Chris an <crohrmeier@LaBellaPC.com>; Kea ng, Roger
<rkea ng@LaBellaPC.com>; Beall, Barbara <bbeall@LaBellaPC.com>; Stephanie Ferradino
<stef@ferradinofirm.com>; Teressa Bakner <TBakner@woh.com>
Subject: FW: [Ext] Re: 239 Washington
CAUTION: This email originated outside of the City network. Please contact IT Support if you need assistance
determining if it's a threat before opening attachments or clicking any links.
Hi James,
Below are our responses to the points you brought up via email after the last City pre-app
meeting. Let us know if there are any questions.
Thanks!
Sara
See attached a few record drawings per the City and DOT. Unsure if you have this
information already or not, but we wanted to do some confirmations on this storm culvert.
It was initially connecting underneath West Ave but around 2006 it was filled and closed
up. This was mentioned within the Army Corp. letter, we just want to be 100% sure on this
due to other development happening near the DEC wetland and for drainage purposes.
Do you have any additional information regarding this culvert that we may not have? Any
possible old locations or even pictures in this area that show a filled in culvert? This
information will help show separated storm water storage areas. In regard to the culvert
under West Avenue, the manhole in the road shows no incoming culvert from West
Avenue. Also, the 2004 NYSDEC letter from Alan Koechlein states that he made a
site inspection with the NYSDOT engineer who assured and showed him that there
was no culvert reconstructed under West Avenue from the Mohr property to the
10/8/24, 12:57 PM Mail - James Salaway - Outlook
https://outlook.office365.com/mail/id/AAMkADBlZDg4YmU2LWFkMTItNDhmNC1hNTJjLTkwMGU1NmYwOTM5ZgBGAAAAAAACZ82oEoYoQqE1L6L…1/3
property on the west side of West Ave. Furthermore, there is an outlet culvert from
the northern end of the Mohr property to the east to Outlook Ave. Refer to Sheet
C100 illustrate all these conditions.
- Is there a better picture, detail, or rendering of what the basin area will look like once
completed? Does it follow more or less the blue book design for a retention basin or is it
following a different design due to the area being just graded in that way? The NYSDEC
2016 Blue Book Standard and Specifications for Sediment Basins specifies that a
sediment basin is a temporary basin. Given that the project proposes grading of a
permanent retention basin, representing the practice as a sediment basin would be
inaccurate. In addition, since no new impervious cover is proposed and given the
small tributary watershed, designing the practices as a stormwater pond in
conformance with the design manual would also be inaccurate. As such, the
retention basin will function similar to a pretreatment forebay with a permanent
water surface and overflow mechanism that allows for the settling of sediment
while controlling discharge rates.
For the stormwater calculations, what method(s) were used? (I see TR-20 and TR-55 after
reading thoroughly through the SWPPP. Any others?) The methodology for the
hydrologic and hydraulic analysis of the pre- and post-development conditions is
outlined in Section 3.1.1 of the SWPPP narrative. This approach is consistent with
the July 31 2024 NYSDEC Stormwater Management Design Manual which states, in
Section 4.7 and 4.8, that when addressing the overbank and extreme flooding
design criteria, TR-55 and TR-20 are to be used to determine peak discharge rates.
Furthermore, Section 17.6 of the City UDO specifies that the most current version of
the design manual serves as the official guide and specification for stormwater
management and that practices designed and constructed in accordance with the
manual is presumed to meet the standards imposed by the City Ordinance.
- For the Sub-Catchment Area, how was the overall area chosen? Is this an accurate
representation? Per Section 7.1 of the 2024 design manual a subcatchment is a
relatively homogenous area of land which produces a volume and rate unique to
that area. The subcatchment boundary is determined using existing (and proposed
under post-development) topography. Subcatchment lines originate at high points
on the topography and run perpendicular to the contour lines until reaching a
design point. The pre-development and post-development subcatchment areas
follow the methodology outlined in Section 7.1 of the design manual. Refer to
Figures A-5 and A-6 in the SWPPP. Furthermore, Section 17.6 of the City UDO
specifies that the most current version of the design manual serves as the official
guide and specification for stormwater management and that practices designed
and constructed in accordance with the manual is presumed to meet the standards
imposed by the City Ordinance.
- Will this land development negatively or positively effect the adjacent land owners? For
example, all the homes on Outlook Drive have sump pumps and specifically where the
water is being directed to the stormwater inlet within the Cities easement, the homeowner
south of the design point stated that the water can get as high or higher than their outlet
which I believe outlets out of the bottom of the stone wall and also discharges into the
design point location. They also pointed out that water comes into their basement during
intense storms as this design point area fills up rather quickly. Would this project be able
to alleviate any of those issues? The issues cited by the adjacent landowners are an
existing conditions problem without the proposed project constructed and would
continue should the project not progress forward. In addition, during a site visit
LaBella observed that the existing culvert (design point) within the City easement
10/8/24, 12:57 PM Mail - James Salaway - Outlook
https://outlook.office365.com/mail/id/AAMkADBlZDg4YmU2LWFkMTItNDhmNC1hNTJjLTkwMGU1NmYwOTM5ZgBGAAAAAAACZ82oEoYoQqE1L6L…2/3
has limited inflow capacity and recommend that the City perform maintenance on
the culvert to reestablish unrestricted drainage. The project demonstrates that
runoff generated by the project site would be less than or equal to the pre-
development conditions, as required by Sections 4.7 and 4.8 of the 2024 Design
Manual as well as GP-0-20-001. Furthermore, the proposed grading provided in the
retention basin creates storage on the Mohr property, reducing the amount of
ponding within the City easement adjacent to 29 Outlook Drive. There is no
additional quantity criteria outlined in the 2024 Manual, GP-0-20-001, or Article 17 of
the UDO requiring the Applicant to address existing conditions on adjacent
parcels. As such, the project has met the requirements of the State and City in
terms of water quantity.
- What trees will be removed vs. any added? Based on the drawing it looks like a complete
clear cut within the parcel while saving onto a few trees along the edges. Sheet C140 will
be revised to include a limit of clearing line.
- Is there any geotechnical information you could provide? It appears the only information
provided is through the NRCS website Soil Survey. Previous City projects, including the
storm water project on Outlook Drive, the bedrock is fairly shallow. The Laid stone wall
near the design point for the stormwater is all rock that was taken out for that project and
just placed there instead of hauling. The City is surprised to see that the SWPPP states
bedrock is greater than 6' deep, we don't believe this to be the case. A geotechnical
report has not been prepared for the project site. The grading is based upon The US
Department of Agriculture (USDA) Web Soil Survey which provides surficial soil
conditions for a specified study area, refer to Section 2.2 of the SWPPP narrative.
- Could you label the existing contours in a few more spots for clarity on the mapping. We
do see the point elevations around the site but a few more existing contour call outs will
help. Sheet C100 and C140 will be revised to clarify existing grades.
- Phase 1 vs. Phase 2. Will they happen back to back or will phase 1 be complete, sit for a
while, then phase 2 would start? Does this effect the stormwater in any way? Sheet C150
will be revised to change the word “phase” to “sequence”. The project is a single-
phase project. What is currently shown as “Phase 1” and “Phase 2” on C150 is to
demonstrate the project staying under five (5) acres of disturbance during
construction and that the site contractor must temporarily or permanently stabilize
as they go rather than have all area disturbed at once. This is due to the project not
pursuing a five (5) acre waiver.
- Are there any provisions to handle invasive species from spreading (phragmites mainly)?
The SWPPP will be revised to include operations and maintenance of the retention
basin. Regarding keeping phragmites out of the retention basin, it is already
present on site, particularly in the area immediately adjacent to West Avenue,
around the smaller southern wetland, in a drainage ditch between the residential
homes on Overlook Avenue and the subject property and along Washington
Avenue. See the attached photolog. Phragmites can spread both by rhizomes and
by windblown seedheads, so keeping phragmites out of the detention basin will be
very difficult.
Sara Drury, EIT
LaBella Associates | Civil Engineer, NY Stormwater Resource Specialist
518-266-7307 direct
518-273-0055 office
10/8/24, 12:57 PM Mail - James Salaway - Outlook
https://outlook.office365.com/mail/id/AAMkADBlZDg4YmU2LWFkMTItNDhmNC1hNTJjLTkwMGU1NmYwOTM5ZgBGAAAAAAACZ82oEoYoQqE1L6L…3/3