HomeMy WebLinkAboutMINUTES - 10091990 - 2.5 005
TO: BOARD OF SUPERVISORS
FROM: J. MICHAEL WALFORD, PUBLIC WORKS DIRECTOR
DATE: October 9, 1990
SUBJECT: JUNE 12, 1990 BOARD REFERRAL-DRAINAGE REQUIREMENTS
ON MINOR SUBDIVISION NO. 73-86, WALNUT CREEK AREA
SPECIFIC REQUEST(S)OR RECOMMENDATION(S)&BACKGROUND AND JUSTIFICATION
I. Recommended Action:
1. ACCEPT report of the Public Works Director regarding the "collect and convey" drainage
requirement for Minor Subdivision No. 73-86 being developed by Lawrence and Martha
Kimmich; and
2. DETERMINE if Minor Subdivision No. 73-86 is to be granted an exemption from the
"collect and convey" requirements of the Subdivision Ordinance Code under Section 92-
6.002 of the code; and
3. If an exemption is to be granted, MAKE the necessary findings and ESTABLISH the
following as an alternative of "collect and convey" at the option of the developer.
a) All drainage to and from the site shall be conveyed across said site in an
adequate, maintainable, open drainage way to the existing canal siphon.
b) Developer shall execute a recordable agreement accepting unto himself and future
owners of the above drainage way all responsibility for future maintenance and
liability.
Continued on Attachment: x . SIGNATURE:
_ RECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMITTEE
APPROVE _ OTHER
SIGNATURE(S):
ACTION OF BOARD ON October 9. 1990 APPROVED AS RECOMMENDED X_ OTHER X
After hearing testimony from Bud Murphy of the Flood Control Division and Mr.
Lawrence Kimmich, the AppTi:cant, the Board ACCEPTED the Report set forth in Recommendation
No. 1 above, made'--appropriate findings and GRANTED an exemption with conditoions, and
approved the Recommendations set forth in No. 3 A, :B.`andk.0 ,above.
VOTE OF SUPERVISORS
UNANIMOUS (ABSENT 2 1
AYES: NOES:
ABSENT: ABSTAIN: I hereby certify that this Is a true and correct copy of
an action taken and entered on the minutes of the
Board of Supervisors on the 4atik shown.
ATTESTED: -�" 94
JMW/MFK:gm PHIL BATCHELOR,Clerk of the Boarl
a:BO9b.t10 of Supervisors and County Administrator
Orig. Div: Public Works Department (AD) By 'Deputy
cc: County Administrator
Community Development Department
Mr. & Mrs. Kimmich
Engineering Services
Flood Control
Drainage Requirement, MS 73-86
October 9, 1990
Page 2
c) Developer shall install 180 linear feet of 27 inch diameter reinforced concrete storm
drain pipe in Cedarbrook Court to mitigate the accumulative hydrology impact
from this development. The length of storm drain shall be decreased if necessary
so as not to exceed $14,580 in construction costs including inspection fees.
H. Financial Impact:
The financial impact to the County if an exemption is granted is unknown.
III. Reasons for Recommendations and Background:
Mr. Kimmich owns approximately two acres in the Cherry Lane area of Walnut Creek. The site
contains several structures including one house and a cottage. Mr. Kimmich wants to minor
subdivide his site into four lots with one of the lots containing the two residences.
IV. Consequences of Negative Action:
Unfortunately, drainage in the area is surface flow except for an old inadequate culvert that .
crosses Mr. Kimmich's property and discharges into the ground depression at the Contra Costa
..Canal siphon. North of the siphon, downstream of the Kimmich site, there.are no drainage
facilities for approximately 1500 feet.
We have had several engineers review the site and vicinity to determine the least costly drainage
solution that meets the requirements of "collect and convey". They have concluded that all of
the potential solutions are not economically feasible for a four lot subdivision. Attached is a copy
of a report on the matter. It should be noted that the downstream developed properties do not
even contain a ditch to convey the sheet flow.from the Kimmich site and the 13 acre upstream
of the site.
CCUERA COSH CO__4-Y FLOOD CCHIROL AND ViA= CONST.,. ATICK DISnUCr
255 GLA= DRIVE, MARMEZ, CALMFCRN:EA
DATE: January 18, 1990
TO: J. P. Murphy, Assistant Public Works Director, Flood ntz 1
i
ESS: Robert D. Agnew, Associate Civil Engineer ?�, 7/ �
SCB3=: MINCIZ SIOUVISICN 73-86, FIELD TRIP
:+1003-73-86=
Reference is made to Milt Kubicek's November 15, 1989 Write-it-don't Say It
memoranda mi to Bud Murphy regarding Minor Subdivision 73-86. Milt wanted
this development reviewed for potential solutions or potential participants
in the solution to collect and convey for this minor subdivision. He
requested our tions for this drainage problem.
On January 4, 1990 I met the minor subdivision applicant, Mr.Kimmich, at the
site. Mr Kimmich explained to me that the application for M5 73-86 has
expired. He plans to refile for a new minor subdivision application. He
wanted to know what Cts tions would be so that he could make a
decisicn as to appeal to the Board of Supervisors or other avenues to get an
exception to collect and covey.
Mr. Ki nen i cel showed me his Property, where the pati i r storm drain is
-.-located, and where the sto=water- discharges frim a storm drain into a low
area at the northern part of his property. The low area is located within
the Contra Costa Canal right of way area. He showed me the S.P.R.R. right
of way area, the Contra Costa Canal right of way area, arra the watershed to
the south that drains into his minor subdivision area. He said that he had
lived there for seventeen years and has never seen the low area filled with
water, and has never seen it ponded. He also believes that the existing
pipe on his property that drains Francis Way, upstream F him, is
Plugged. It is hard to believe, because, at the dream area boundary of
his property the watershed area is thirteen and one half acres. He did not
say that he has seen water exiting from his pipe in the Contra Costa Canal
right of way area.
There exists a short rxbm in the minor subdivision file dated May 21,
1958 to T. E. Burlingame from Paul Summa. The subject matter of this
is "Drainage Zone #44" - C. E. Tate, 2687 Cherry Lane, Walnut
Ctmek.
111he drainage to the north of the above mentioned property has been blocked
over a period of years. In 1954 or 1955 Erxgnan built Maywood Estates to
the south and discharged the drainage into the rear of the above mentioned
property. In its present state, where there is nothing but a lake at the
rear of Tate's property, the blocking was done prior to Ordinance 792.
Wand you please Contact Mr. Tate and give him what info=ation you can an
the status of a drainage zone in this area.,,
dere are several expensive alternative solutions to discharge the
stoaaters into an adequate storm drainage facility fresn this mirror
subdivision site. They are:
A. Install a storm drainage pipe east across Cherry lane, drown Cora Court
to. the W.C. channel, which is located approximately 900 feet from
Cherry lane
B_ Install a storm drain in Cherry Lane and along Cherry Lane northerly to
the ey-stirj storm drainage system in Treat Blvd. located abort 1600
feet to the north.
C. Install a system along the existing drainage way across Contra Costa
Canal and across private property to and down the street to connect
into a storm drain system in Elmracod Drive, located approximately 950
feet north of the Contra Costa Canal right of way.
D. Install a storm drain system within the S.P.R.R. right of way northerly
to discharge into Line A storm drain system of 44B located in Janes
Poad, which is approximately 3.100 feet fram the minor subdivision
site. I understand you are not in favor of this alternate as this
storm drain may obstruct future development of the S.P.R.R. corridor.
E. Allow the minor subdivision to discharge a into the existing law area
within the Contra Costa Canal area.. Construct a pezmanent storm drain
system to pick up the storm drain from Francis Way and the minor
subdivision site to the westerly property line of Kimmic h's property
and bulkhead the pipe at the railroad right of way line. In the
future when the S.P.R.R. right of way is approved as a transportation
co�zidor, and requires dram , then the bulldieaded storm
drain in the minor subdivision site can be connected to the
transportation corridor storm drain system. This could be done if the
applicant can get a drainage release from the Contra Costa Water
District for as long as there is no permanent outfall storm drain
system. But when the permanent storm drain is finally hooked up to the
storm drain in the S.P.R.R. right of way then the drainage release can
be relingaishe .
I do not understand why, during heavy runoff periods, no water has pcnded up
in the low area within the C.C. Canal riot of way or the possibility that
the pipe on his property is plugged. Thirteen arra a half acus is a fairly
large watershed area to be ignored. Perhaps there is a system within his
prcperty that drains elsewhere unknown to Mr. Rimmich.
In the uppermost part of the thirteen and a half acre watershed, located
southerly of the Kimmic h minor subdivision site, there may be a potential
far two minor subdivisions to develop into three or four lots. Presently,
there lots have surface runoff across the Maywood Estates Subdivision site
to the Francis Way storm drain system. So if these properties were ever to
develop, they would have to collect arra convey approximately 350 feet to tie
in to the storm drain system in Francis Way, located south of Kimmich's
2
g*vperty. It is my�•..pinion that there may be a i+o� passibility, or no
passible potential. for future development in the near future in this
watershed other than the Kimmich property.
Mr. Kimmich hired CIM to prepare a drainage report for this minor
subdivision application, dated April 7, 1989. They calculated the ten year
storm water runoff of 10.7 cubic feet per second and they were told that at
no time in the past 20 years has the Kimmich property flooded. Ston waters
are conveyed both in the 10-inch pipe and as sheet flow across the Kinmich
property, thence through and across ss the path arra northerly frim the C. C.
Canal Riot of Way area. They that the existing flow path be
cont?*need and no conversion of the storm waters be made. This statement
conflicts with Mr. K]mmich's statement to me that the water has never panded
in this low area within the C. C. Canal riot of way area. This low area is
where C. C. Canal makes a syphan under this low area. At one time this lour
area to the north was conveyed flows from Mr. Kimmich's property.
Ap�aa*ent1 y the area to the north, in the 40's or the 50's, has filled up
this swale.
It appears that there is no recent storm drain solution for this Minor
Subdivision application. It may be possible that Mr. Kimmich may get a
drainage release from the Contra Costa anal. He informed me that he had
appttaactled the C. C. Canal people and found out that they had made special.
cmxmssions for certain cases to allow developments to discharge into their
canal. He may try to get a drainage release based on the hardship on his
case.
I am available to discuss this Mirror Subdivision problem with you arra Milt.
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