natural resource overlay district (nrod)

NATURAL RESOURCE OVERLAY

DISTRICT (NROD)

OR 213: I-205 – REDLAND ROAD O’XING(OREGON CITY) PROJECT

Methodology

Ground-truthed boundaries of wetlands and

streams

Ground truthing for streams and wetlands based on

the approved Army Corps of Engineers wetland

delineation methodology

Boundaries reviewed and concurred with by Army

Corps of Engineers and Department of State Lands

Determined buffers based on Oregon City

Municipal Code 17.49.110Table 17.49.110

Protected

Feature Type

(See

Definitions)

Anadromous

Fish-bearing

Stream

All Other Features

Intermittent

Stream <

25%, drains

< 100 acres

All Other Streams

(Intermittent or Perennial)

Delineated

Wetland

Minimum

Required

Width

200’ 15’ 50’ 200’ 50’

Slope

Adjacent to

Feature

Any < 25 % > 25 % for

less than 150

feet (see

Note 2)

> 25 % for 150

feet or more

(see Note 2)

Any

Starting Point

for

Measurements

from Feature

Top of Bank Top of Bank Top of Bank

Top of bank to

break in > 25

% slope (See

Note 3) + 50’

Delineated

Edge of Title 3

Wetland

Maximum

Disturbance

Allowance

See Section 17.49.120

Mitigation

Requirements See Section17.49.180 or 17.49.190

Methodology

Oregon City Municipal Code 17.49.20 states:

The NROD protects as one connected system, the

habitats and associated functions of the streams,

riparian corridors, wetlands and the regulated

upland habitats found in Oregon City.

NROD Buffer Impacts

Natural

Resource

Feature/NROD

Buffer

Proposed Impact Acreage of Impact

Stream 14 No Impact No Impact

Stream

15/Wetland E

Culvert installation/Road widening (Clackamas River

Drive) 0.451

Stream

16/Wetland F Road widening (OR 213)

0.621

Pond 18 Road widening (Washington Street) 0.154

Wetland A Road realignment (Washington Street) 0.098

Wetland B Road realignment (Washington Street) 1.588

Wetland C Road realignment (Clackamas River Drive) 0.855

Wetland D Road realignment (Clackamas River Drive) 0.223

Wetland G Road widening (OR 213) 0.019

Wetland H Road widening (OR 213 and Redland Road) 0.354

Wetland I Road widening (OR 213) 0.357

Total 4.720

NROD Buffer Conditions Wetland B

Wetland B

Wetland B

NROD Buffer

Impact Area

NROD Buffer Conditions Wetland C

Wetland C

Wetland C NROD

Buffer Impacted Area

NROD Buffer Conditions Stream 16

Impact Area

Wetland F

Stream 16

NROD Buffer Conditions Stream 16

Impact Area

Wetland G

Stream 16

NROD Buffer Conditions Stream 15

Impact Area

Stream 15

NROD Mitigation

Oregon City Municipal Code 17.49.10:

B. Protect floodplains and wetlands, and restore them

for improved hydrology, flood protection, aquifer

recharge, and habitat functions.

C. Protect upland habitats, and enhance connections

between upland and riparian habitat.

The NROD mitigation site is

located 225 feet north of the

proposed project

NROD Mitigation Site

NROD Mitigation Planting List

762 trees per acre

436 shrubs per acre

Total: More than 3,500 trees

and 2,000 shrubs

NROD Mitigation Site Success Criteria

5 years of site monitoring

80% survival of trees and shrubs

No more than 10% cover of noxious weeds

(noxious weeds defined by Oregon Department of

Agriculture)

Conclusions

Mitigation based on habitat quality designed to

improve:

Water quality by providing shade and large

vegetation structure

Wildlife habitat through native species planting and

noxious weed removal.

GEOLOGIC

HAZARDS

US 10-01

AND

VARIANCE

VR 10-01

OR 213: I-205 – REDLAND ROAD O’XING(OREGON CITY) PROJECT

Retaining Wall #1

Length = 808 feet

Height = 2 to 18 feet (Avg. Ht. = 13 feet)

OCMC 17.44.060(D): Wall faces shall not exceed

5 feet

13-foot variance requested for wall face

Retaining Wall #1

Retaining Wall #1

Retaining Wall #2

Length = 109 feet

Height = 2 to 7 feet

Wall sits above an 18-foot (max.) high cut slope

OCMC 17.44.060(D): Wall faces shall not exceed 5 feet and total cut and fill slopes shall not exceed 15 feet

2-foot variance requested for wall face

3-foot variance requested for finished cut slope below the wall

Retaining Wall #2

Retaining Wall #2

Wall Surface Types

Wall Surface Types

Grounds for Granting a Variance

The variance from the requirements is not likely to cause

substantial damage to adjacent properties by reducing light, air,

safe access or other desirable or necessary qualities otherwise

protected by this title;

The request is the minimum variance that would alleviate the

hardship;

Granting the variance will equal or exceed the purpose of the

regulation to be modified;

Any impacts resulting from the adjustment are mitigated;

No practical alternatives have been identified which would

accomplish the same purpose and not require a variance; and

The variance conforms to the comprehensive plan and the intent

of the ordinance being varied.

Wall #1 – Variance Grounds

Impacts to Holcomb Overlook properties reduced with one wall vs. terraces

Greater buffer for private properties

Less disturbance to existing slope - greater global stability

Protects Holcomb Blvd. bridge

Expert structural design and drainage management

Architectural detailing to mitigate appearance

Minimizes highway footprint

Maintains integrity of adjacent terrain

Consistent with Comprehensive Plan goals and policies

Wall #2 – Variance Grounds

New pedestrian connection will be provided

Retaining wall to stabilize existing man-made steep slope for Washington Street realignment

Trying to balance wall face and slope heights

Wall and slope heights needed to fit roadway between private property and UP railroad tracks

Expert structural design drainage management

Elaborate landscaping plan to beautify slope

Architectural detailing to mitigate appearance

Consistent with Comprehensive Plan goals and policies