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Detailed descriptions of each of the scenarios modeled.
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Scenario Name |
Description |
|
IMPERV |
changes in % impervious and % commercial area over entire
basin. Changes were a 5, 10, and 50% increase, and 5% decrease in the %
impervious and % commercial. % commercial changes were limited by amount
of "natural" area, with natural areas reduced by same amount that commercial
was increased. |
|
CHAN_ROUGH |
Increase Manning's N for the channels by 0.0185, which
is the difference between Clean, Straight Banks channel and a Stony, Winding
Pools and Shoals channel |
|
CHANNELIZ |
Channelization of Miller Cr Mainstem down to middle DNR
data site. Two methods: short fractal (500 ft) and long fractal (1500 ft)
used to compute new lengths. Slope werechanged by back-calculating the
"rise" from the original length and slope, and using the new length to
re-calculate a new slope. |
|
TRIBSEW |
Upper Basin tribs were converted into stormsewers by:
changing channel to pipe, reducing roughness, and decreasing length/increasing
slope. NO changes in Miller Mainstem. |
|
DET_POND |
Detention ponds were added to each modeled Miller Creek
Trib from headwaters to the middle DNR data site. Ponds were exact same
size, with same outlet, as for the Miller Hill Mall basin. Ponds were put
in place just before trib entered Miller Creek, and downstream (and in
addition to) any existing features such as natural ponds, culverts, etc.
Stormsewered sections had detention ponds added as well. Where multiple
tribs combined before entering Miller Creek, each trib had a pond added
PRIOR to the joining of the tribs |
|
ROUGH_IMPERV |
Increased roughness and surface storage by ratio of 1.1
(10%) for all subcatchments in Model. no other changes performed. Scenario
proposed as possible BMP, to increase retention time and depression storage
of rainfall on impervious areas. |
|
COMBO |
Two combinations: 1st, without BMP's, includes 10% increase
in imperv and commercial areas, channelized Miller Cr (500 ft fractal),
and tributaries in upper basin converted to stormsewers (as in tribstosewer
model). 2nd combo includes previous changes along with BMP's: detention
ponds at end of all tribs, increased mainstem channel roughness, increased
impervious roughness and surface storage (see rough_Imperv scenario), and
trib stormsewers roughness increased to 0.0255 (corresponding to the max
n for metal corrugated pipe). |
|
RESIDENT |
altered buildup rate of Tot-P in residential landuses;
increases and decreases of 10% in buildup rate for both hi-density and
low-density residential landuses. Only Tot-P data altered. |
4 December, 1999 Jesse Schomberg
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