v7, fully self-contained - neighbourhood and lot, one slider. The 1 m lidar is embedded in this file, not just its conclusions: 1,681 ground elevations on a
41x41 grid at 2 m over an 80 x 80 m box centred on the house. Source USGS 3DEP, tile USGS one metre x57y442 IN Central MarionCo 2016,
flown 11-18 Mar 2016, NAVD88 feet. Water from USGS 03351005 White River at Ravenswood, datum 709.98 ft, 0.36 mi away, which crested at
726.86 ft, 5:15 pm Sat 15 Aug 2026. No network calls, no external references.
Ravenswood, 1.6 x 1.6 km, USGS 3DEP resampled to 20 m. Same water level as the lot view below, and water is limited to ground actually connected to the river. Red marker is the house.
Water level on the lot
Contours every 0.5 ft. Values under the roofline are interpolated by the lidar vendor, not measured - they represent ground at the
foundation. Fill is a level surface, which is why the whole lot wets at once; it does not solve flow.
At this level
Lag behind the river
river crested 726.9 ft
Vs your floor
floor 725.5 ft
Feature
Elev
Water
Floor = grade + one 7.5 in step, per your description. Grade re-measured at 724.97 ft; earlier runs gave 724.88. Treat +/-0.1 ft as the noise floor.
When it comes back off
Clears below
Elev
Fastest
Slowest
Your finished floor
725.5
Sun 06:30
Mon 00:30
Grade at the house
724.9
Sun 10:15
Mon 06:45
Garage apron
724.7
Sun 12:15
Mon 09:45
Lowest adjacent grade
723.9
Sun 15:50
Mon 15:40
Cul-de-sac pavement
723.9
Sun 16:35
Mon 17:10
Randall Ct sag, 40 m S
723.1
Sun 19:50
Mon 23:35
Lowest point on the lot
722.9
Sun 20:40
Tue 01:20
Fastest follows the NWS Nora forecast, slowest the NWS Ravenswood forecast point, both mapped onto USGS 03351005 by the offset
measured at the crest. Observed: peak 16.88 ft 17:15 Sat, 16.52 ft by 22:45, falling ~0.1 ft/hr and accelerating - between the two cases.
Elevation key (ft NAVD88)
Gauges, records and how this flood ranks
Gauge
Distance
Gives
Record
USGS 03351005 White River at Ravenswood
0.36 mi
Stage only. Datum 709.98 ft NAVD88 (+/-0.11). All elevations here.
30 Jun 2012 ->
USGS 03351000 White River near Nora, 82nd St
2.9 river mi up
Stage and discharge. Datum 710.51 ft. All cfs, and anything pre-2012.
1913 ->
NWS RVNI3 / NORI3
-
Forecast points. Recession shape only, never elevations.
-
Ravenswood gauge, every annual peak in its record, paired with discharge at Nora in the same event.
Year
Date
Stage
Water surface
Nora flow
2026
15 Aug
16.88
726.86
34,500
2013
19 Apr
14.01
723.99
25,200
2017
5 May
12.59
722.57
21,400
2025
7 Apr
11.89
721.87
19,100
2015
28 Jun
11.88
721.86
18,700
2018
5 Apr
11.62
721.60
18,600
2024
13 Apr
11.56
721.54
18,000
2020
12 Jan
10.66
720.64
17,100
2019
27 Apr
10.62
720.60
16,100
2022
18 Feb
10.44
720.42
15,100
2023
5 Mar
8.41
718.39
11,000
2016 / 2021 / 2014 / 2012
-
7.11-11.16
714.5-721.1
1,600-14,400
Those eleven pairs give ~0.31 ft of water surface at Ravenswood per 1,000 cfs at Nora in the upper range.
Rank
Date
Nora flow
Nora stage
Ravenswood
1
26 Mar 1913
58,500
22.40
no gauge
2
15 Aug 2026
34,500
~21.1
726.86 measured
3
19 May 1943
32,400
18.19
no gauge
4=
23 Apr 1964
30,400
18.65
no gauge
4=
30 Jun 1957
30,400
18.04
no gauge
6
1 Jan 1991
28,700
19.19
~725.1 estimated
What constrains the peak on your lot: at least 723.9 ft, because you saw the waterline at the cul-de-sac end of the driveway at
3 pm; at most 726.9 ft, because the lot cannot exceed the river. Your floor at 725.5 sits near the middle of that band. The 3 ft lag measured at 3 pm
and the short crest argue the lower half; efficient street conveyance argues the upper half. Nothing available resolves it.
The 1991 figure is extrapolated from the eleven pairs above, not a reading - no gauge existed at Ravenswood then. It cross-checks: 1991 stood
1.91 ft lower at Nora, and the extrapolation puts it 1.79 ft lower here. This flood carried 20% more water than 1991 and ran ~1.8 ft higher at your
address. In 98 years only 1913 was bigger.
Not an official flood-inundation map and not a hydraulic model. FEMA NFHL regulatory 1% surface is 727.9 ft at cross-section 18097C_345,
82 m away. Generated 16 Aug 2026.