HomeMy WebLinkAboutRe: report on drainage analysis 441" -
AFR 07 197 14:00 MATTKE ENGINEERING, INC. 6127830-700 T0: P02
Mattke Engineering# Inc.
7671 Central Ave. N.E. Fridley, MN 55432 • (612)783-0300 �G
April 7 , 1997
Z . Peter & Katheryn Sawicki Z
4510 North Shore Drive
Orono, MN 55364
John & Beth Bessesen iL
4500 North Shore Drive
Orono, MN 55364
re: Report on Drainage Analysis
Dear Home owners:
At your request, I have investigated the factors leading to
failure of the culvert under the Sawicki driveway to carry the
discharge from a 4.0 inch rainfall on August 6, 1995, which
resulted in water damage to your properties. In summary, the
cause of the problem was the construction of homes up the hill on
Tonkaview, which increased the runoff rate in the County Road 19
ditch to the point that the culvert under the Sawicki driveway
could not handle the increased discharges. The excess water then
overflowed the ditch and ran down the edge of the County Road 19
pavement to the Sawicki driveway. There, the flaw apparently
split, with about half continuing down the County road to the
Bessesen driveway, and the other half running down along the
Sawicki driveway. The overflow water apparently overtaxed the
private drain systems of the two residences, resulting in flood
damage to the homes. In addition, the flows eroded the bank
beside the Sawicki driveway and around both houses, caused damage
to the slopes, and deposition of eroded material in both yards.
Before construction of the homes on Tonkaview, there was a
drainage area contributing water to the culvert of approximately
2.6 acres. The dr-ainage area had approximately 0.4 acres of
impervious surface) and the remaining area was wooded with
grassed areas.' The sail type is a Kilkenny loam, described as a
soil susceptable to erosion. Based upon these factors, a SCS
curve number for runoff is estimated at CN-66 for the condition
before the homes were constructed. When the SCS hydrology model
is applied to the above conditions, a 4.0 inch rainfall would be
expected to generate a peak discharge at the culvert of
approximately 2 cYs.
Based upon visual evidence, the original culvert under the
Saw 1crni driveway wua s 15tI CHP, buried deep enough that the water
= Resi dentia! &Corn;ncrcia:Deuc.opm.ent
1
APR 07 197 14:01 MATTKE ENGINEERING, INC. 6127830300 T0: P03
would have to get about 18 inches deep before it would overflow
onto the County road. This culvert had the capacity to handle
approximately 5 cfe without overflowing. Thus, without the homes
on the hill, the original culvert was able to handle a 4.0 inch
rainfall. In fact, the original culvert had the capacity to
handle up to approximately a too-year rainfall event (5•
inches/24 hours) , which would have produced a 5 cfs (approx.)
discharge at the culvert, before construction of the homes on the
hill.
construction of the homes on Tonkaview increased the drainage
area (of the original culvert) to approximately 3.55 acres, and
increased the runoff curve number to 75 for the culvert
watershed= Recent changes by the County and City (the County
added curbing, and the City added a 611 pVC pipe draining to the
west from the northwest corner of the intersection of Tonkaview
and CR 19) have reduced the drainage area to approximately 3.39
acres. Even after these recent reductions in drainage area by
the County and City, the peak discharge at the culvert remains
approximately 6 cfs iii a 4.o inch rainfall
Recent changes to the County Road 19 drainage included lowering
the culvert, increasing its capacity toapproximately 6 cfs (the
same discharge as was produced by the 4.o inch storm) , and
placing curbing along the edge of the pavement. statistically,
.we can expect a 4.2 inch storm to hit this area every_ 10 years,
on the average. Consequently, we can expect that, if no changes
are made to the current drainage system, the existing culvert
will have insufficient capacity about: every 10 years or GO.
Placing the curbing included plaoiRg a raised (about 1-1/2 inch)
lip of bituminous pavement in front of your driveways. In
additiob, the pavement was graded to pitch away from the Bessesen
driveway, so flows oomin down the curb line will now gross the
County road without rUnn�ng into the 8e4sasen driveway. 'Thus it
appears that the Beason-an house is now protected from CR 19 water
ru-n i ng down the driveway.
Oft the other hand, placing the curbing along the County road has
increased the potential for damage from CR 19 water to the
dawicki. home. As the curb is higher than the ditch bank, culvert
overflows can nolonger escape down the County road pavement, but
instead will overtop the dutch bank +end erode a path directly
toward the SaVIOU home. It will only take a few minutes of
erosion before the entire ditch floe will be running around and
through the Sawicki house. It is expected that the damage to the
Sawicki home could far faxoeed that suffered in 1995 if the
culvert capacity is exceeded under present conditions.
With the potential for damage to homes, it is ordinary
engineering practice to provide protection for at .least the loo-
year event, 5.9 inches/24 hours. With the homes on the hill,
such an event would be expected to produce a discharge at the
culvert of about 11 cfs, even after the recent changes by the
APR 07 '97 14:02 FWTTKE ENGINEERING, INC. 61 30300 TO: Pod
City and county. ThuS the present drainage Syste�a is
insufficient by engineering standards,
It should 4160 be holed, that with the erosion potential of the
moil in this area, special care Should be taken to prevent
erosion. At present, the ditch leading to the culvert is deep
with eroded material depaaited in the last several montna, Abd
the culvert is nearly blooked: The present potential for water
denago to the Sawicki home is actua17:p much higher than stated in
the calculations above, as these calculations were based upon a
fully functioning culvert. Additionally,, as this loose eroded
zaterial is carried downstream through the culvert and on, it
will deposit in the yards of both homes. Consequently it is
expected that you both will Suffer damages from deposition even
Without a 4 inch rainfall.
In spry, increased runoff fro* the homes on Tonkaview resulted
in increased stage (water elevation) at the culvert under tete
Sawicki driveway, to the point that it overflowed, ran down the
driveways, and resulted in damages. With the modifications
recently malas to the drainage system, the bassesen house is
probably protected from CR 19 water, hQweyar the Sawicki home is
in (jreater peril. without Modifications to the present system,
the next 4$ inch rainfall muid result in more extensive damage
to the Sawicki home than in 1995.
If you have any questions, please give me a call. I will be
eivailsab16 to evaluate any proposed correction of the problem by
the city and/or county las your representative), and to
participate in litigation, should that be necessary. If
liticlation is necessary, we will prepare some fancy charts and
drRvIngs to illustrate the "whys and whereforesh.
I hereby certify that thib report was prepared by me or under my
diva—c—t 6upervirion, and that I am a duly Registered Profeimional
Engineer uftder the State of Minnesota statutes, Sections 326.02--
336.16.
Tedd W. Mattke, Ph.D. , p.E.
xx PE #13612
/ t
PM
TIP
40
or ,, I '
Iff
�lj
org it
t.
APR 04 197 17:29 MATTKE ENGINEERING, INC. 6127830300 TO: P03
D. --� ,.....�... ,..�
M-p-
��,33a.Lo .4c
aAAow ! 0.Y.2 A: i +0,/o .4 C.
y/ 0,73 0...z' 0,17o44 A-).r"-V�
oe of
d 0.Sl,,;.i O./L A 4.
/asa.r••a'sr?.,,.�.y�- •�, s
.2.(. --
swr r"o' : gKa KkC� KKE "� �0�4. -r ytoe t3
C� .��+-�. ��+. = �'O a�o n�� 0.4/x►t I'+PER vi o.t s
a-61 (fo)t o.Y�98�
Es-
(0.y 0 4 t ,r,,.v-a ,..4d.,,(� 3.39
rLaw..-f .t •+�
5
1260
/,gnu
APR 04 197 17:30 MATTKE ENGINEERING. INC. 6127830300 T0: P05
RL%l Um
pa48 Z
LMID.......1.......2.......3.......E 1.......5.......6.......7.......8.......9......10
1 ID IiJ►t8R AGE a>Ni.=, SWW i BA88LM, OR0110, !Of
2 ID SCS MR=34 a. 1YPt II SIwo CMITIOII.S ISM , 4.0 3]i/24A1t
*ULM
* M PM TM IIICREIi3Al'! 70 NUISIa 10 0.1 BR
3 14 6
4 Io 4 0
5 Al PIPE N1'1'S m
6 101 aABi-2.60'AC.1 C1a66, 1C=1010'
7 Ba .00406 0 1
8 pS 4.0
* 24 RR. TYPE 11 SCS RdWAM - Sala 15 16-20 U'VAU
* 4.0' 1=91 13 24 a0D>1S 5 RaI>aP1. 7 0.1 24MI
*
9 11 6
* IErmIIAli11uz
10 PC 0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009
11 pC 0.010 0.011 0.012 0.013 0.014 0.015 0.016 0.017 0.018 0.019
12 PC o.o2o 0.021 0.022 0.023 0.024 0.026 0.027 0.028 0.029 0.030
13 PC 0.031 0.032 0.034 0.035 0.036 0.037 0.03a 0.040 0.041 0.042
14 PC 0.043 0.045 0.046 0.047 0.049 0.050 0.051 0.053 0.054 0.055
15 PC 0.057 0.058 0.060 0.061 0.063 0.064 0.066 0.067 0.069 0.070
16 PC 0.072 0.074 O.M 0.077 0.079 0.080 0.082 0.084 0.085 0.087
17 pC 0.089 0.o91 0.093 0.095 0.097 0.100 0.103 0.106 0.109 0.3.11
1.8 PC 0.115 0.118 MU 0.124 0.127 0.130 0.134 0.137 0.140 0.144
19 PC 0.148 0.131 0.155 0.159 0.163 0.167 0.171 0.176 0.180 0.185
20 PC 0.189 0.194 0.199 0.205 0.210 0.216 0.222 0.328 0.236 0.242
21 PC 0.250 0.258 0.266 0.276 0.287 0.298 0.312 0.326 0.363 0.416
22 PC 0.500 0.584 0.638 0.673 0.689 0.702 0.714 0.725 0.734 0.743
23 PC 0.751 0.758 0.766 0.772 0.779 0.785 0.790 0.796 0.801 0.806
24 PC 0.812 0.816 0.821 0.826 0.829 0.834 0.838 0.842 0.845 LU9
25 PC 0.853 0.857 0.860 0.664 0.867 0.870 0.874 0.877 0.880 0.883
26 PC 0.886 0.889 0.892 0.895 0.898 0.900 0.903 0.906 0.908 0.910
27 PC 0.911 0.913 0.915 0.917 0.919 0.920 0.922 0.924 0.925 8.927
28 PC 0.929 0.930 0.932 0.933 0.935 0.936 0.938 0.939 0.941 0.942
29 PC 0.944 0.945 0.946 0.948 0.949 0.951 0.952 0.953 0.956 0.956
30 PC 0.957 0.958 0.960 0.962 0.962 0.963 0.965 0.966 0.967 0.968
31 PC 0.969 0.971 0.972 0.973 0.974 0.975 0.976 0.977 0.978 0.978
32 PC 0.981 0.982 0.983 0.984 0.985 0.986 0.987 0.988 0.989 0.990
33 PC 0.991 0.992 0.993 0.994 0.995 0.9% 0.997 0.998 0.999 1.000
34 PC 1.000 1.000 1.000 1.000 1.000
* usa SItDROLOGIC paRa1 sls
* mm., 1) Am IS lvmm IN Egm K=ON m cm
L2) OD CARD REMUSIN UG, L-0.6*1c, 6Jn8sSBD IN SLS
35 0 66
36 CD .l0
*
*
37 23
APR 04 197 17:04 MATTKE ENGINEERING. INC. 6127830300 T0: P02
RM 6muy
YLOB ill CUBIC FM m 5=0
TINS is HOBS, mu 11 Sgt11IIB Kim
PUK TIMI Of 3vwm nX POR W Mil PERIOD B➢SU MIIQAI TDD;Of
MU3TIOM SYIYION YEAR PEAK 6-HOUR 24-M 72-MM LIU olke Nil Sl m
A8DR06iM a PIPE i. 12.10 1. 0. 0. 0.01
s A
APR 04 197 17:05 MATTKE ENGINEERING, INC. 6127830300 T0: P03
f~
8$C-1 I1�O! Pin 1
LIDSID.......1.....,.2.......3.......4.......5.......6.......7.......8.......9......10
1 ID NITER DIM01 aLEM s FT-VI- - nonw_ w
2 TD S.4 D'f=tCns 71 8R_ ME Ti OVIA "�f- . ..
3 IT 6 300
4 IO 4 0
5 KK Fix 41d7$A m
6 xM AM-3.39 AC., CP741 rah fur.
7 131 .00m O 1
4 PB 5.9
* 24 BR. m II 8C3 U Mp'LLL - &W a3 211-20 BbWAU
* 5.9* UWALLL If 24 SW 5 RIWL 7 0.3 24MI
9 is 6
* NOR TYPR 11 RIIWIU
10 PC 0.000 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009
u PC 0.010 O.OU 0.012 0.013 0.014 0.015 0.016 0.017 0.018 0.019 -
12 PC 0.020 O.D21 0.022 0.023 0.014 0.026 0.027 0.018 0.029 0.030
13 PC 0.031 0.012 0.034 0,035 0.036 0.037 0.038 0.040 0.041 0.042
14 PC 0.043 0.045 0,046 0,047 0,049 0.050 0.051 0.053 0.054 0.086
15 PC 0.057 0.058 0.060 0.061 0.063 0.064 0.066 0.067 0.069 0.070
16 PC 0.072 0.074 0.075 0.077 0.079 0.080 0.082 0.084 0.085 0.087
17 PC 0.089 0.041 0.093 0.095 0.097 0.100 0.103 0.106 0.109 0.112
18 PC 0.115 0.118 0.121 0.1.24 0.12? 0.130 0.134 0.137 0.140 0.144
19 PC 0.148 0.151 0.1% 0.159 0.163 0.167 0.171 0.176 0.180 0.185
20 PC 0.189 0.194 0.199 0.2% 0.210 0.216 0.222 0.228 0.235 0.242
21 PC 0.250 0.255 0.266 0.276 0.287 0.298 0.312 0.328 0.363 0.416
22 PC 0.500 0.584 0.63E 0.673 0.689 0.702 0.714 0.725 0.734 0.743
23 PC 0.751 0.758 0.766 0.712 0.799 0.785 0.790 0.796 0.801 0.806
24 PC 0.811 0.416 0.821 0.825 0.829 0.834 0.838 0.842 0.845 0.849
25 PC 0.853 0.857 0.S60 0.864 0.867 0.870 0.874 0.877 0.880 0.883
26 PC 0.886 0.889 0.892 0..$" 0.898 0.900 0.903 0.906 0.908 0.930
27 PC 0.911 0,913 0.915 0.917 0.919 0,920 0.922 0.924 0.925 0.927
28 PC 0.929 0,930 0.932 D.933 0.935 0.936 0.938 0.939 0.941 0.942
29 PC 0.944 0.945 0,946 0.948 0.949 0.951 0.952 0.953 0.9% 0.956
30 PC 0.957 0.958 0.960 0.%l 0.962 0.963 0.%$ 0.%6 0.967 0.%8
31 PC 0,%9 0.971 0.972 0.973 0.974 0.975 0.976 0.977 0.973 0.979
32 PC 0.981 0.982 0.983 0.984 0.985 0.986 0.987 0.988 0.989 0.990
33 PC 0.991 0.992 0.993 0.994 0.995 0.9% 0.997 0.998 0.999 1.000
X PC 1.000 11.000 1.000 1,000 1.000
* BLO$Y1bEDIAOIC PAIIAM8 m
* 110m: 1) 1581 I9 EYPWO IN 8 ul"MILES 011 BA GRD
+� 2) DD CM II>1P0M U511 LAG, L-0.6*Tc, WOW If HOOKS
35 L9 0 75.
36 OD .06
*
*
37 !3
APR 94 197 17:05 MATTKE ENGINEERING. INC. 61278 T0: PO4
Rum BMW
to it cmc PIS?PIR 8B0M
im IK M, an 11 9" KM
PL%K ?IMI OF IVIRIQI Plat PDQ KaEm PMOD um mm ?IKI 4P
OP�lTIOi< 8?l?ION no PM 6-1= 24-MM 71-M AM smi lilt MA
SYDROax IT PIP= U. 12.10 1. 0. 0. 0.01
ti