HomeMy WebLinkAboutAGENDA REPORT 1994 0202 CC REG ITEM 11ICITY OF MOORPARK
AGENDA REPORT
ITEM I I •T
I
To: Honorable City Council
.cc i-.
From: Dirk Lovett, Assistant city Engineer ( '
l�
Date: January 25, 1994 (City ( )uncil Meeting February 2, 1994
Subject: Consider Modifications t) -,xid l t.ions of IPD 93 -1
(G &S Partnership)
BACKGROUND
On September 14, 1993, the City council approved IPD No.
93 -1 providing for the development. of parcels 5, 6, and 7 of
Parcel Map 3828 (G &S Partnership and Mail Marketing). The
developer agreed to all condition- as specified in Resolution 93-
988. This resolution included the -I'--y Engineering Standard
Conditions as they relate to storr r.i -ra off (hydrology and
hydraulics).
During the plan check process it was determined that the
developer could not meet these cor;�- lit.ions without having to
reconstruct storm drain improvemer.•.:= in Science Drive.
The developer's engineer has :3ubmitted a letter (attached)
to the City requesting a modificatic;n t.c• several conditions as
they relate to hydrology standard:.
ANALYSIS
The developer was conditioned to design all drainage to
handle a fifty -year storm and meet all current Ventura County
standards. On -site drainage is p�:.>posed to be deposited into the
storm drain system in Science Cris .
Science Drive drainage was designed in the early 1980's (PM
3828) and plan checked by Ventura 'cunty according to their
standards at that time. The majoi difference in the design
criteria then and now are two -fol::
(1.) Ventura County required cnl} feasible access to the site
during a ten -year storm. However, catch basins in a sump
condition must be designed for a `) -year study. The condition of
approval of IPD 93 -1 requires fear Lt;i,� access during a fifty -year
storm.
(2.) The rainfall intensity (ZonE. J) utilized in the original
hydrology study to design the Science Drive storm drain was about
1/2 of the current County adopted nt:�nsit.y (Zone K).
Page 2
The developer's engineer contends they should be allowed to
design this site pursuant to the parameters established in the
earlv 1980's with PM 3828.
It should be noted, however, than the rainfall intensity
used in that design would not be acceptable according to today's
standards, regulated by Ventura C(unty. It is Staff's belief
that the lesser rainfall int.ensit Zone J) was utilized in the
original design in error.
The requirement t.o design foi a fifty -year storm is a more
conservative approach than the original ten -year storm design
criteria. The fifty -year design standard is consistent with Los
Angeles County Standards and some - it.ies in the County of
Ventura. This higher standard is beneficial in hillside areas
where water in the streets can pi:k up velocity or where standing
water in sump areas can become too deep t_o pass for most vehicles
during heavy storms. Because thi- :s a flat area, only the
standing water would be a proble•r i,ring the peak storm
intensities.
The current conditions approved witli IPD 93 -1 require one
dry travel lane in Science Drive r.liring a fifty -year storm.
Below is a table showing our rougl. calculations of the
hypothetical water depths at the centerline in Science Drive for
10 and 50 year storm [lows under l )t l: t h`= J and K Zone rainfall
intensities:
Rainfall Intensity Zone 10 -Year Storm 50 -Year Storm
Water Depth Water Depth
J roac: dry 4.5 inches
K road dr•� 1 foot
SUMMARY
The developer's engineer is requesting that the City Council
allow them to design the drainage systems consistent with those
parameters utilized with the design of PM 3828 (ten -year storm
capacity and a design rainfall intensity zone of J). This would
provide for feasible access during a '-en -year storm rather than a
fifty -year storm. It is the Engineering Department's opinion
that regardless of the design storm standard used (10 or 50
year), the correct rainfall intensity zone of K should be
utilized. If the developer is bound by the existing conditions,
off -site storm drain improvements will. require upgrading.
This can be done by either upsizinq the existing storm drain in
Science Drive, or running parallel pipe :.rom Science Drive to the
Arroyo Simi. City Engineering's r.oug:n estimate for the cost of
the parallel pipe would be betweer S "7 ),G :C to $100,000 (dependent
on the pipe size) plu:3 20° for de.: :fin an:i, City and Flood Control
fees.
January 25, 1994
Page 3
The developer's engineer should be required to prepare the cost
estimate for review by the City En,aineer's office in order to
obtain a more precise estimate.
If the developer is allowed to design for a ten -year Storm, one
foot of standing water is foreseeable in Science Drive during the
peak flow.
RECOMMENDATION
The City Council may wish to ',cake either of the following
actions:
(1.) Revise Conditions 73b and 74(j (attached) to require that
one dry travel lane in Science Drive be available during a ten -
year storm rather than a fifty -year st.orrn.
or
(2.) Deny the applicant's request ro modify the conditions.
JAN25.AGE
PALOS VERGES ESTATES
(310) 375-2556
FROM L. A. (213) 772-1555
FAX (310) 378-3816
WESTLAKE VILLAGE
(805) 494 4499
FAX (605) 494-4221
February 18, 1994
City of Moorpark
111 A Poindexter
Moorpark, CA 93021
SOUTH BAY ENGINEERING CORPORATION
304 TEJON PLACE
PALOS VERDES ESTATES. CALIFORNIA 90274
Attn: Public Works Dept.
Dirk Lovett, Ass't City Engineer
Subject: G & S Project - Science Drive
SBEC File No. 93079 -4
Dear Dirk:
RAYMOND L. OUIGLEY
DONALD E. DAWSON
CONSULTING ENGINEERS
RECEIVED
j4% 2 0 1994
During the last plan check on the drainage, A4r. Chow (plan checker) stated that the street
(Science Drive) must provide for one land of traffic to pass during a 50 year event storm based on
the "K rainfall zone.
In talking to you after hearing the comments from Mr. Chow, there was a misunderstanding
about the rainfall zones to be used. You stated that we must comply with condition No. 73C and
74A which relates to current Ventura Cunty hydrology standards.
The subject site is nothing more than the combining of lots and vacation/dedication of a new
cul -de -sac within the approved and recorded Parcel Map in connection with the construction of
two new buildings.
The usage has not changed since the original map was approved, plans prepared and approved by
Ventura County, then constructed as they exist today.
The original storm drain system and hydrology was prepared by D.M.J.M. study was based on a
rainfall zone "J" for a 10 year event storm with a Q 10 of 1.39 c.f.s. /acre. With the conclusion that
the flap gate on their design would be closed during a 100 year event storm, however the peaking
time of the Arroyo Simi and Parcel,Map system is different, whereas the water discharging from
the system would have drained before the Arroyo Silni would /will peak.
D.M.J.M. study also states that in the event of residual rainfall occurring with the Arroyo Simi at
peak flow, storage within the drainage system will provide for 18,680 c.f together with additional
storage on lots and in street area.
Our firm has prepared hydrology studies based on both the rainfall zones "J" and "K" and we
have determined that most conditions can be met as outlined in the condition of approval with the
exception of numbers 73b, 73c, 73g, and 74a, which all deal with current Ventura County flood
control hydrology directly related to 50 year event storm. That is, the feasible access to the
project. That access being one dry travel lane under a rainfall zone of "K" which is greater than
the constructed system which was designed and constructed on a rainfall zone of "J" basis.
Our site design has taken into account the 50 year event storm where the design has been
provided to allow only the original undeveloped Q 10 to enter the storm drain system by use of on
site detention until the peak storm has passed. In this manner the main back bone drainage system
will not be over burdened.
It should also be pointed out that uur client is the only uwners/develupers that has had this
condition related to the 50 year event storm imposed on them within this Parcel Map area that we
are aware of . Other's within this development area have only been required by the City to
provide for the 10 year event storm and they where never required or requested to prove the
existing was designed correctly to comply with anv condition.
This was brought to my attention by our design engineer who did the development plans for most
of the existing buildings along Science Drive of %vhich the follow where prepared by our firm,
Parcel A, B, and E of Parcel Map 4287 and Parcel 4 of Parcel Map No. 3828 where the total
hydrology had to be designed for a 10 year event storm.
We hereby request that the conditions of approval be modified in such a manner as to make the
statement that the existing storm drain system is satisfactory based on not increasing the allowable
flows within the system as shown on the original system design hydrology prepared by D.M.J.M
and approved for the development area by Ventura County
Your assistance in scheduling this matter either before staff that can make these decisions or
placing this matter before the City Council as soon as possible will be greatly appreciated.
Very truly yours,
SOUTH BA Y ENGINEERING CORPORA TION
Brace W. Berlea
rice- President
BWB:gh 94007C /ami
s
INDUSTRIAL PLANNED DEVELOPMENT IPD 93 -1
APPLICANT: G &S Partnership
DATE: 9/7/93
b'. y Al1�:catchi: ;,in sump locations shall carry a 50 -year
frequencp�r.Storm;
r(�sG
C. All catch basins on continuous grade shall carry a 50-
year storm;
d. All catch basins in a sump condition shall be sized such
that depth of water at intake shall equal the depth of
the approach flows;
e. All culverts shall carry a 100 -year frequency storm;
f. Drainage facilities shall be provided such that surface
flows are intercepted and contained prior to entering
collector or secondary roadways;
g. Under a 50_year..frequency storm, all. collector streets
shall� be. - provid@c* with a minimum of one trAvdl 'lane with
a goal that = local, residential streets shall have one
travel lane available;
h. Drainage to adjacent parcels shall not be increased or
concentrated by this development. All drainage measures
necessary to mitigate storm water flows shall be provided
by the applicant;
i. All drainage grates shall be designed and constructed
with provisions to provide adequate bicycle safety to the
satisfaction of the City Engineer;
J. If the land is to be occupied is in an area of special
flood hazard, the applicant shall notify all potential
buyers in writing of this hazard condition;
k.* All flows from on -site channels, ribbon gutters or other
similar devices shall be deposited into the storm drain
system prior to entering streets. If necessary, the
storm drain shall be extended beyond the public right -of-
way through easements to eliminate surface flow between
parcels. On -site storm drains and drainage easements
located outside the City's right -of -way shall be
maintained by the applicant his heir or successor's.
1. All channels shall be constructed of tan colored concrete
as approved by the Director of Community Development.
IPD93.1 /.LLA93.8 Page -24- Resolution No. 93-
FA
INDUSTRIAL PLANNED DEVELOPMENT
APPLICANT:
DATE:
IPD 93 -1
G &S Partnership
9/7/93
A.A*,71r. The applicant shall submit to the City of Moorpark for review
and approval, a detailed Soils Report certified by a
j f'r•�� Registered Civil Engineer in the State of California. The
�� report shall include a geotechnical investigation with regard
,Is At to liquefaction, expansive soils, and seismic safety.
l The grading plan shall incorporate the recommendations of the
approved Soils Report. Note: Review of the soils and
geotechnical report by the City's geotechnical consultant may
be required by the City Engineer. If so, the applicant shall
reimburse the City for all costs including the City's
administrative costs.
72. The applicant shall construct a driveway(s) from Science Dr .
onto the subject property. The driveway(s) shall be
constructed per Ventura County Road Standard Plate E -2
(rev.B).
STORM RUN -OFF
73. The applicant shall demonstrate, by a diagram, for each
building pad to the satisfaction of the City Engineer as
follows:
a. Adequate protection from 100 -year frequency storm; and
b. Feasible access during a 50 -year frequency storm.
C. Hydrology calculations shall be per current Ventura
County Standards.
�. The applicant shall submit to the City of Moorpark for review
and approval, drainage plans, hydrologic and hydraulic
calculations prepared by a Registered Civil Engineer; shall
enter into an agreement with the City of Moorpark to complete
public improvement and shall post sufficient surety
guaranteeing the construction of all improvements.
The drainage plans and calculations shall indicate the following
conditions before and after development:
a. Quantities of water,. , water flow rates, major water
courses, drainage areas and patterns, diversions,
collection systems, flood hazard areas, sumps, sump
locations and drainage courses. Hydrology shall be per
the current Ventura County Standards except as follows:
IPD93.1 / LLA93.8 page -23- R6201atioa No. 93-
AGENDA REPORT
CITY OF MOORPARK
TO: Honorable City Council
FROM: Dirk Lovett, Assistant City Engineer
IJ
DATE: February 1, 1994 (City Council Meeting of February 2, 1994)
SUBJECT: Consider Modifications to Conditions of IPD 93 -1
Agenda Item 11.1. - Storm Drain Estimate (G &S Partnership)
This report is being submitted as an additional item of information for Agenda Item 11.I
In the summary of City Council Agenda Item 11 the City Engineering Department
provided a rough estimate for the required storm drain, should one dry travel lane be required
in Science Drive during a 50 -year storm.
It was estimated that the price could range from $70,000 to $100,000, not including
contingencies, plus 2056 for design and agency fees (pipe size could range between 24 inches
to 48 inches - to be calculated by the developers engineer)
Without yet calculating the hydraulics and sizing the pipe, the developers engineer has
assumed that the 48" pipe will be necessary and has provided their estimate. Engineering has
reviewed this estimate and made the appropriate rev,.sions (attached).
The revised developers Engineers estimate indicates that a 48" pipe could be installed for a
total cost of $145,751 (including contingencies, des:gr, and agency fees), not $161,254 as
they estimated.
It is the City Engineers opinion, without the benefit of further hydraulic calculations, that a
smaller pipe should be able to handle this water �f designed to operate under pressure.
DIL:cc
cc: City Manager, Deputy City Manager, Department Heads
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SOUTH BAY ENGINEERING CORPORATION
Civil Engineering- surveying
304 Tejon Place .
Palos Verdes Estates, CA 90274
Telephone (310) 3752556
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PRELIMINARY
* * ** CONSTRUCTION COST ESTIMATE * * **
Job: 93079 Estimate Date: 30 January 1994
50 YEAR STORM DRAINAGE RETROFIT SCIENCE DRIVE By: B.W.BERTEA
NOTE: 'c' after Item Dollar Amount Indicates Contingency Item.
* ** STORM DRAINAGE * **
Main Lines:
48" RCP Pipe .......................
Manholes:
Standard Manhole No4 ...............
Miscellaneous:
Quantity Unit -Cost Item Total
690 LF 101.00 69,690.00 c
!-
Main Lines Subtotal: 69,690.00
2 EA 3,200.00 6,400.00
Manholes Subtotal: 6,400.00
Outlet Structure..... .............. 1 EA 16,000.CO
Traffic control .................... LS
Grouted Rip Rap to 1911 ............. 100 SF 6.00
Remove /replace Pavement............ 3360 SF 2.00
Miscellaneous Subtotal:
STORM DRAINAGE Subtotal:
Contingencies:
STORM DRAINAGE Total:
Page 1 of 3
c
v
16,000.00 c
12,000.00 c
600.00 c
6,720.00 c
35,320.00
111, 410.00 \' �-
II lkf I
Constructibn Cost Estimate - 93079
Quantity Unit Cost Item Total
* ** CONSULTANT FEES & SERVICES * **
Civil Engineering Design:
Topography /Aerial Survey........... LS
off -site Improvement Plans......... LS
Civil Engineering Design Subtotal:
Construction Survey:
Construction Staking............... LS
Construction Survey Subtotal:
CONSULTANT FEES & SERVICES Total:
* ** FEES, PERMITS, ETC. * **
Engineering (Plan Check):
CityFee @ 6 % ..................... LS
CountyFee ......................... LS
Engineering (Plan Check) Subtotal:
Construction Permits /Fees:
City Fee @ 6 %...................... LS
County Fee ......................... LS
Construction Permits /Fees Subtotal:
FEES, PERMITS, ETC. Total:
1,500.00
8,500.00
10,000.Ou
4,200.00
------- - - - - --
4,200.00
14,200.00
�.16 -:-G0-
* ** MAJOR CATEGORY TOTALS (Does Not Include Contingency Costs):
STORM DRAINAGE:
CONSULTANT FEES & SERVICES:
FEES, PERMITS, ETC.:
TOTAL COST WITHOUT CONTINGENCIES:
0 3ri7'
111,410.00
14,200.00
- - -- }8_432_00,
144 :mo0-4
* ** SUMMARY (Including Contingency Costs):
TOTAL OF COSTS SUBJECT TO CONTINGENCY: 111,410.00
CONTINGENCIES @ 1�r ::' =�� : 30 11j 'Y1
TOTAL OF COSTS NOT SUBJECT TO CONTINGENCY: _�.3 , 3'?�_-_0 0 ? -'3 2 f 'Z
TOTAL ESTIMATED COP +STRUCTIGN COST: 1611- . 50
Page 2 of 3
TOTAL OF COSTS NOT SUBJECT TO CONTINGENCY: Estinate - 93079
NOTES:
1. Since South Bay Engineering corporation has no control over the cost of
labor, materials, or equipment, or over the contractor's methods of
determining prices, or over competitive bidding or market conditions,
our opinions of probable project cost or construction cost provided for
herein are to be made on the basis of our experience and qualifications
and represent our best judgment as design professionals familiar with the
construction industry, but South Bay Engineering Corporation cannot, and
does not, guarantee that proposals, bids, or the construction cost will
not vary from opinions of probable cost prepared by the firm.
2. Itens shown under SUMMARY as OTHER COSH is a portion of Major Category
Totals that do not include any contingencies and is not an additional
cost item.
Page 3 of 3
PAL05 VERDES ESTATES
(310) 375-2556
FROM L. A. (213) 772-1555
FAX (310) 379-3816
WESTLAKE VILLAGE
(805) 494 -4449
FAX (805) 494 -4221
February 18, 1994
City of Moorpark
111 A Poindexter
Moorpark, CA 93021
SOUTH BAY ENGINEERING CORPORATION
304 TEJON PLACE
PALOS VERDES ESTATES CALIFORNIA 90274
Attn: Public Works Dept.
Dirk Lovett, Ass't City Engineer
Subject: G & S Project - Science Drive
SBEC File No. 93079 -4
Dear Dirk:
RAYMOND L. OUIGLEY
DONALD E.DAWSON
CONSULTING ENGINEERS
RECEIVED
.JAN 2 0 1994
During the last plan check on the drainage, Nir. Chow (plan checker) stated that the street
(Science Drive) must provide for one land of traffic to pass during a 50 year event storm based on
the "K rainfall zone.
In talking to you after hearing the comments from Mr. Chow, there was a misunderstanding
about the rainfall zones to be used. You stated that we must comply with condition No. 73C and
74A which relates to current Ventura Cunty hydrology standards.
The subject site is nothing more than the combining of lots and vacation/dedication of a new
cul -de -sac within the approved and recorded Parcel Map in connection with the construction of
two new buildincy
Tile usage has not changed since the original map was approved, plans prepared and approved by
Ventura County, then constructed as they exist today.
The original storm drain system and hydrology was prepared by D.M.J.M. study was based on a
rainfall zone "J" for a 10 year event storm with a Q10 of 139 c.f.s. /acre. With the conclusion that
the flap gate on their design would be closed during a 100 year event storm, however the peaking
time of the Arroyo Simi and Parcel,Map system is different, whereas the water discharging from
the system would have drained before the Arroyo Simi would /will peak.
D.M.J.M. study also states that in the event of residual rainfall occurring with the Arroyo Simi at
peak flow, storage within the drainage system will provide for 18,680 c.f. together with additional
storage on lots and in street area.
Our firm has prepared hydrology studies based on both the rainfall zones "J" and "K" and we
have determined that most conditions can be met as outlined in the condition of approval with the
exception of numbers 73b, 73c, 73g, and 74a, which all deal with current Ventura County flood
control hydrology directly related to 50 year event storm. That is, the feasible access to the
project. That access being one dry travel lane under a rainfall zone of "K" which is greater than
the constructed system which was designed and constructed on a rainfall zone of "J" basis.
Our site design has taken into account the 50 year event storm where the design has been
provided to allow only the original undeveloped Q 10 to enter the storm drain system by use of on
site detention until the peak storm has passed. In this manner the main back bone drainage system
will not be over burdened.
It should also be pointed out that our clieni is the only owners/developers that has had this
condition related to the 50 year event storm imposed on them within this Parcel Map area that we
are aware of . Other's within this development area have only been required by the City to
provide for the 10 year event storm and they where never required or requested to prove the
existing was designed correctly to comply with any condition.
This was brought to my attention by our design engineer who did the development plans for most
of the existing buildings along Science Drive of which the follow where prepared by our firm,
Parcel A, B, and E of Parcel Map 4287 and Parcel 4 of Parcel Map No. 3828 where the total
hydrology had to be designed for a 10 year event storm.
We hereby request that the conditions of approval be modified in such a manner as to make the
statement that the existing storm drain system is satisfactory based on not increasing the allowable
flows within the system as shown on the original system design hydrology prepared by D.M.J.M
and approved for the development area by Ventura County
Your assistance in scheduling this matter either before staff that can make these decisions or
placing this matter before the City Council as soon as possible will be greatly appreciated.
Very truly yours,
SO UTH BA Y ENGINEERING CORPORA TION
— X44 Z01 C � �_5
Bruce PV Bertea
rice- President
BWB:gh 94007C /ami .
s
INDUSTRIAL PLANNED DEVELOPMENT IPD 93 -1
APPLICANT: G &S Partnership
DATE: 9/7/93
All= catch b 8 .'.:,in sump locations shall carry a 50 -year
frequencyystorm;
f7a !31 h
rPsa c. All catch basins on continuous grade shall carry a 50-
year storm;
d. All catch basins in a sump condition shall be sized such
that depth of water at intake shall equal the depth of
the approach flows;
e. All culverts shall carry a 100 -year frequency storm;
f. Drainage facilities shall be provided such that surface
flows are intercepted and contained prior to entering
collector or secondary roadways;
g. Under a 50-year-frequency storm, all collector streets
shall�be provI.404,ewith a minimum of one travel lane with
a goal that = - - local, residential streets shall have one
travel lane available;
h. Drainage to adjacent parcels shall not be increased or
concentrated by this development. All drainage measures
necessary to mitigate storm water flows shall be provided
by the applicant;
i. All drainage grates shall be designed and constructed
with provisions to provide adequate bicycle safety to the
satisfaction of the City Engineer;
J. If the land is to be occupied is in an area of special
flood hazard, the applicant shall notify all potential
buyers in writing of this hazard condition;
k.' All flows from on -site channels, ribbon gutters or other
similar devices shall be deposited into the storm drain
system prior to entering streets. If necessary, the
storm drain shall be extended beyond the public right -of-
way through easements to eliminate surface flow between
parcels. On -site storm drains and drainage easements
located outside the City's right -of -way shall be
maintained by the applicant his heir or successor's.
1. All channels shad. be constructed of tan colored concrete
as approved by the Director of Community Development.
nm93.1 /.LL7►93.8 Page -24- R000lution No. 93-
FAA
INDUSTRIAL PLANNED DEVELOPMENT
APPLICANT:
DATE:
IPD 93 -1
G &S Partnership
9/7/93
The applicant shall submit to the City of Moorpark for review
and approval, a detailed Soils Report certified by a
�('r•1I Registered Civil Engineer in the State of California. The
report shall include a geotechnical investigation with regard
is to liquefaction, expansive soils, and seismic safety.
V The grading plan shall incorporate the recommendations of the
approved Soils Report. Note: Review of the soils and
geotechnical report by the City's geotechnical consultant may
be required by the City Engineer. If so, the applicant shall
reimburse the City for all costs including the City's
administrative costs.
72. The applicant shall construct a driveway(s) from Science Dr .
onto the subject property. The driveway(s) shall be '
constructed per Ventura County Road Standard Plate E -2
(rev.B).
STORM RUN -OFF
73. The applicant shall demonstrate, by a diagram, for each
building pad to the satisfaction of the City Engineer as
follows:
a. Adequate protection from 100 -year frequency storm; and
b. Feasible access during a 50 -year frequency storm.
C. Hydrology calculations shall be per current Ventura
County Standards.
The applicant shall submit to the City of Moorpark for review
and approval, drainage plans, hydrologic and hydraulic
calculations prepared by a Registered Civil Engineer; shall
enter into an agreement with the City of Moorpark to complete
public improvement and shall post sufficient surety
guaranteeing the construction of all improvements.
The drainage plans and calculations shall indicate the following
conditions before and after development:
a. Quantities of water,.. water flow rates, major water
courses, drainage areas and patterns, diversions,
collection systems, flood hazard areas, sumps, sump
locations .and. drainage courses. Hydrology shall be per
the current Ventura County Standards except as follows:
TPD93.1 / LLA93.8 Page -23- Resolution do. 93-
Ell