AGENDA # 7
MEMORANDUM
TO: Mayor and Town Council
FROM: W. Calvin Horton, Town Manager
SUBJECT: Text Amendments to Stream Definitions and Field Verification Criteria in the Chapel Hill Land Use Management Ordinance
DATE: November 10, 2003
Enactment of the attached ordinance would implement revisions in the Chapel Hill Land Use Management Ordinance regarding stream definitions and field verification criteria. Adoption of the attached resolution would establish policies regarding stream classification procedures and contested stream determinations.
BACKGROUND AND DISCUSSION
The Chapel Hill Land Use Management Ordinance (the Ordinance) became effective on January 27, 2003, and includes broad and significant changes in regulatory requirements for development and redevelopment within the Town’s planning jurisdiction. To implement the new regulations, Town staff developed specific procedures for receiving, reviewing, and processing development applications. A significant area of change in the new regulations involves the Resource Conservation District and associated definitions and verification criteria to be used when classifying streams as perennial, intermittent, or ephemeral.
Town Engineering Department staff developed work sheets and guidelines for making stream determinations based on the new regulations. Approximately thirty stream determinations have been completed by Town staff using the definitions and verification criteria currently in the Land Use Management Ordinance. In making those determinations, we encountered difficulties in reasonably and consistently classifying some stream segments and in identifying the beginning and ending points of segments with different classifications. Based on that experience, we suggested that some revisions in the Ordinance language were necessary.
On April 14, 2003, the Council adopted a separate resolution authorizing the Town Manager to establish a Technical Advisory Committee (the Committee) to review the current stream definitions and field verification criteria in the Ordinance and to provide recommended revisions for the Council’s consideration.
On June 23, 2003, the Committee presented to the Council its report entitled “Recommendations for Revisions in Stream Definitions and Field Verification Methods”. Attachment 1 is a copy of the Committee’s report that includes general policy recommendations and recommendations for revisions in the stream definitions and verification criteria currently included in the Ordinance. The Council received the report and directed the Manager to continue working with the Committee to develop and propose for the Council’s consideration specific Ordinance language revisions regarding stream definitions and verification criteria.
On August 12, 2003, the Committee prepared a supplemental report that provided more detailed information concerning recommended revisions in the Land Use Management Ordinance language. Attachment 2 is a copy of the Committee’s supplemental report.
On September 2, 2003, the Town Planning Board reviewed the Committee’s recommendations and Attachment 3 is a summary of the Planning Board’s action.
On October 20, 2003, a Public Hearing was held to receive comments from citizens regarding proposed revisions in the Ordinance language and suggested policy statements concerning stream determinations.
PUBLIC HEARING KEY ISSUES
The following comments were presented at the Public Hearing:
Key Issue: Include certain streams that do not precisely meet the definitions
Committee recommendation’s 5 and 6 include policy recommendations for classifying streams that do not precisely meet the Ordinance stream definitions.
At the October 20 Public Hearing, interest was expressed in establishing criteria and procedures for classifying natural variant and urbanized.
Manager’s Comment:
We agree and have included technical language in the Field Procedures for Classification of Streams document regarding streams that do not precisely meet Ordinance definitions.
Key Issue: Include a length of time (5 years) that a stream classification stands.
Recommendation 9 includes a policy for the length of time a stream classification stands, unless the hydrologic characteristics of the watershed have altered the stream. The length of time recommended is 5 years.
At the October 20 Public Hearing, there was no comment concerning this policy recommendation.
Manager’s Comment:
We agree that a policy establishing the length of time for which a particular stream classification remains valid is reasonable. We think that a minimum period of 5 years is appropriate, unless there have been significant changes in hydrologic conditions.
Key Issue: Implement a policy that allows for re-evaluation of stream origins that were determined prior to January 27, 2003.
Recommendation 10 includes a policy for the re-evaluation of stream classifications made prior to January 27, 2003.
At the October 20 Public Hearing, there was no comment concerning this policy recommendation.
Manager’s Comment:
We agree that a policy establishing the re-evaluation of certain stream classifications made prior to January 27, 2003 is reasonable. We think that stream classifications made more than 5 years ago should be subject to the new definitions.
Key Issue: Clearly differentiate between the definitions of “Ephemeral Stream” and “Ditch”.
At the October 20 Public Hearing there was a comment concerning the differentiation between the definition of a “ditch” and the definition of an “ephemeral stream”.
Manager’s Comment:
The proposed definition of “Ditch or Canal” includes the phrases “man-made channel” and “typically dug through inter-stream divide areas” to distinguish them from ephemeral streams. We think this is language would adequately differentiate a ditch or canal from an ephemeral stream.
Key Issue: Consider how the revised definitions are working and periodically review the changes in the months ahead.
At the October 20 Public Hearing there were comments suggesting that the proposed Ordinance revisions be reviewed in the future to determine how well they are performing and whether or not further revisions are in order.
Manager’s Comment:
We agree that periodic review is important and will present a status report to the Council within one year following implementation of the recommended changes.
Key Issue: In considering any political issue concerning stream classifications, make certain that the definitions and criteria will stand on their own to the extent feasible.
At the October 20 Public Hearing, there were comments concerning the importance of assuring that definitions and verification criteria are reasonable and defensible.
Manager’s Comment:
We believe that the proposed definitions and criteria are reasonable and defensible, and will stand on their own under scrutiny.
Key Issue: Establishing Process for Consultation with Experts.
Recommendation 8 of the Committee was to implement an appeals procedure using a panel of professionals. On October 20, 2003, we reported that the Town’s existing appeals process through the Board of Adjustment is available. In addition, we stated that we expect to involve experienced and knowledgeable professionals where classification opinions are contested and where, in the opinion of the Manager, consultation with one or more experts would be of assistance before making a final administrative decision.
At the October 20 Public Hearing, interest was expressed in establishing a procedure for consultation with experts regarding contested stream determinations.
Manager’s Comment:
We agree that it would be reasonable for the Council to establish as a matter of policy that consultation with independent experts would be appropriate where it appears to the Manager that there is substantial conflicting evidence regarding a stream determination performed by Town staff in accordance with the Ordinance. We think that such policy guidance on administrative procedure would most appropriately be established through Council Resolution rather than by Ordinance. We have included the following language in the attached Resolution that would establish applicable policy guidance:
BE IT RESOLVED that the Council directs the Manager, in making a determination regarding the classification of any stream pursuant to Section 3.6.3 of the Land Use Management Ordinance, to consider the analysis presented to him by any interested party. Where the analyses presented by any party or parties and Town Staff indicate substantial conflicting evidence regarding the proper stream classification, the Manager may consult one or more independent persons with training and expertise in stream classification issues prior to making a final administrative decision. The Manager shall make a written report to the Council of any advice received as a result of such consultation.
Alternatively, the Council may determine that this procedure should be established in the Land Use Management Ordinance itself. If the Council so determines, the following alternative language could be inserted, at the end of Section 2 of the attached Ordinance, to add a new final paragraph to Section 3.6.3(a) of the Land Use Management Ordinance:
“In making a determination regarding the classification of any stream pursuant to this Section, the Manager shall consider the analysis presented to him by any interested party. Where the analyses presented by any party or parties and Town Staff indicate substantial conflicting evidence regarding the proper stream classification, the Manager may consult one or more independent persons with training and expertise in stream classification issues prior to making a final administrative decision. The Manager shall make a written report to the Council of any advice received as a result of such consultation.”
If the Council chooses to include this language in the Ordinance, then it would be appropriate to remove the above suggested language from the Resolution.
RECOMMENDATIONS
Planning Board Recommendation: The Planning Board discussed the proposed Ordinance text amendment on September 2, 2003, and voted 8-1 to recommend approval. Please see Attachment 3, Summary of Planning Board Action.
Manager’s Recommendation: That the Town Council enact the attached Ordinance that would implement revisions in the Chapel Hill Land Use Management Ordinance regarding stream definitions and field verification criteria, and; that the Council adopt the attached Resolution establishing policies regarding stream classification procedures and contested stream determinations.
ATTACHMENTS
1. Technical Advisory Committee Report and Recommendations dated June 23, 2003 (p. 12).
2. Supplement to the Technical Advisory Committee Report and Recommendations dated August 12, 2003 (p. 30).
3. Summary of Planning Board Action on September 2, 2003 (p. 36).
4. State Stream Classification Form and Internal Guidance Manual (p. 37).
5. Technical Document entitled “Field Procedures for Classification of Streams” (p. 45).
AN ORDINANCE AMENDING THE CHAPEL HILL LAND USE MANAGEMENT ORDINANCE REGARDING STREAM DEFINITIONS AND VERIFICATION CRITERIA (2003-11-10/O-3)
WHEREAS, the Council of the Town of Chapel Hill has been concerned about the Land Use Management Ordinance Resource Conservation District stream definitions and field verification criteria; and
WHEREAS, the Town Council finds that revision of the stream definitions and field verification criteria is desirable and that the amendments achieve the purposes of the Comprehensive Plan.
NOW, THEREFORE, BE IT ORDAINED by the Council of the Town of Chapel Hill that the Council amend the Chapel Hill Land Use Management Ordinance as follows:
Section 1: Appendix A, Definitions, of the Land Use Management Ordinance is hereby revised to add and/or modify the following definitions as shown:
The top elevation of a stream’s current active channel.
The defined course (e.g. bed,
ditch, or depression) where a natural or man-made stream of water is
transmitted. A natural or artificial watercourse with a definite bed and banks
that conducts continuously or periodically flowing water. A natural
water-carrying trough cut vertically into low areas of the land surface by
erosive action of concentrated flowing water or a ditch or canal excavated for
the flow of water.
The most recent version of a document entitled “Town of Chapel Hill Design Manual”, which document is hereby incorporated by this reference.
A man-made channel other than a modified natural stream constructed for drainage purposes that is typically dug through inter-stream divide areas. A ditch or canal may have flows that are perennial, intermittent, or ephemeral and may exhibit hydrological and biological characteristics similar to perennial streams.
A stream that flows only
during wet periods of the year and flows in a continuous, natural channel or
depression (including natural springs). The flow may be heavily supplemented
by stormwater runoff. Intermittent streams include those that are shown on the
Town’s Geographic Information System (GIS) coverage, the USGS 7.5 Minute
Quadrangle, or the USDA Orange County Soil Survey (subject to field
verification), and/or those shown as a dashed blue line on USGS maps, in
addition to streams confirmed to be intermittent by field verification by the
Town Manager. A well-defined channel that contains water for only part
of the year, typically during winter and spring when the aquatic bed is below
the water table. The flow may be heavily supplemented by stormwater runoff.
An intermittent stream often lacks the biological and hydrological
characteristics commonly associated with the continuous conveyance of water.
An intermittent stream shall
be confirmed by the Town Manager by at least two (2) of the following:
(a) The
presence of water during periods of wet weather or more than forty-eight (48)
hours after a storm event of at least 0.5" rainfall.
(b)
The presence of geomorphological features that are characteristic
of a fluvial system, such as:
(1)
Riffle/pool sequences
(2)
Areas of alluvial deposition (i.e. point bars)
(3)
Sinuosity
(4)
Fluvially weathered bed materials (i.e. cobbles, gravels,
boulders)
(c)
The presence of a channel or depression (including natural
springs) created by topographic features that is hydrologically connected to
surface waters through surface flow or a pipe.
(d)
The presence of amphibian larvae or benthic macro-invertebrates.
The volume of water carried by
a steam in times other than droughts or above average rainfall.
The 30-year average rainfall, updated each decade to the most recent 30-year period by the National Climatic Data Center.
A natural
or man-made basin that stores surface water permanently at depths sufficient to
preclude growth of rooted plants, including lakes, ponds, and similar water
features. For the purposes of this Section, the surface waters must be part of
a natural drainageway with a continuous discharge during a year of normal
rainfall. Perennial surface waters include those that are shown on the Town’s
Geographic Information System (GIS) coverage (subject to field verification) in
addition to others that are confirmed as such by field verification by the Town
Manager or the North Carolina Division of Water Quality.
A stream that flows throughout
the majority of the year and flows in a well-defined channel. Perennial
streams include those that are shown on the Town’s Geographic Information
System (GIS) coverage, the USGS 7.5 Minute Quadrangle, or the USDA Orange
County Soil Survey (subject to field verification) in addition to streams confirmed
to be perennial by field verification by the Engineering
Department. A well-defined channel that contains water year round
during a year of normal rainfall with the aquatic bed located below the water
table for most of the year. Groundwater is the primary source of water for a
perennial stream, but it also carries stormwater runoff. A perennial stream
exhibits the typical biological, hydrological, and physical characteristics
commonly associated with the continuous conveyance of water.
A perennial stream shall be
confirmed by the Engineering Department by at least two (2) of
the following:
(a)
The presence of continuously flowing water during a year of
normal rainfall.
(b)
The presence of geomorphological features that are characteristic
of a fluvial system, such as:
(1)
Riffle/pool sequences
(2)
Areas of alluvial deposition (i.e. point bars)
(3)
Sinuosity
(4)
Fluvially weathered bed materials (i.e. cobbles, gravels,
boulders)
(c)
The presence of obligate and facultative wetland vegetation, as
identified by U.S. Fish and Wildlife Service species lists, along the stream
channel and banks.
(d) The presence of
fish, amphibian larvae, or benthic macro-invertebrates.
A natural or man-made
basin that stores surface water permanently at depths sufficient to preclude
growth of rooted plants, including lakes, ponds, and similar water features.
For the purposes of this Section, the surface waters must be part of a natural drainageway
(i.e., connected by surface flow to a stream). Perennial Water Bodies shall be
those delineated on the Town's Aerial Topographic Maps, subject to field
verification. A natural or man-made basin that stores surface
water permanently at depths sufficient to preclude growth of rooted plants,
including lakes, ponds, and similar water features. For the purposes of this
Section, the surface waters must be part of a natural drainageway (i.e.
connected to a stream by a channel with intermittent or perennial flow). Perennial
water bodies shall be those delineated on the Town’s Aerial Topographic Maps,
subject to field verification.
A natural or vegetated area adjacent to streams and perennial water bodies through which stormwater flows in a diffuse manner, so that runoff does not become channelized and which provides for the infiltration of runoff and filtering of pollutants. The riparian buffer is measured landward (horizontal distance) from the stream bank on both sides of the stream or from the normal pool elevation of a perennial water body. The riparian buffer shall also “wrap around” the upstream end of the stream origin.
A body of concentrated flowing water in a natural low area or natural channel on the land surface.
The point(s) where the wetted
perimeter of a stream’s cross section has the highest elevation (as referenced
to mean sea level) during normal stream flow.The point on a stream’s
cross-section defined by the bankfull elevation.
A natural or vegetated area
adjacent to watercourses through which stormwater runoff flows in a diffuse
manner, so that runoff does not become channelized and that provides for the
infiltration of runoff and filtering of pollutants. The stream buffers
required by this Section are delineated in Table
3.6.3-2.
A natural water-carrying
trough cut vertically into low areas of the land surface by erosive action of
concentrated flowing water; or a ditch or canal excavated for the flow of
water.
Any Perennial Stream, Intermittent Stream, or Perennial Surface Water as defined herein. Any
intermittent or perennial stream or modified stream or any perennial water body
as defined herein.
Any area of a perennial stream
or regulatory flood plain which is inundated during the base flood discharge. A
permanent or intermittent stream or other body of water, either natural or
man-made, which gathers or carries surface water. Any natural or
man-made conveyance of concentrated surface flow including: (1) any area of a
perennial stream or regulatory flood plain which is inundated during the base
flood discharge, (2) any intermittent or perennial stream, (3) any ephemeral
stream or ditch that frequently transports stormflow, or (4) any perennial
water body. “
A natural or vegetated area
through which stormwater runoff flows in a diffuse manner so that the runoff
does not become channelized and which provides for infiltration of the runoff
and filtering of pollutants. The buffer is measured landward from the normal
pool elevation of impounded structures and from the bank of each side of
streams or rivers.
Section 2. Section 3.6.3 (a) of the Land Use Management Ordinance is hereby revised to read:
“(a) Definitions and Rules of Interpretation
In the interpretation and application of this Article, all provisions shall be: (a) considered as minimum requirements, (b) strictly construed in favor of the public interest and community benefit, and (c) deemed neither to limit nor repeal any other powers provided by Town ordinance or State statute. The following terms and phrases, among others, shall have specific meanings for purposes of this Section, and are defined in Appendix A:
Ditch or Canal
Ephemeral Stream
Intermittent Stream
Land Disturbance
Modified Natural Stream
Obligate and Facultative Wetland Vegetation
Perennial Stream
Perennial Water Body
Riparian Buffer
Stream
Stream Bank
Stream
Channel
Stream Corridor
Streams subject to the provisions of this Article and Article 3.6.4 include those shown on the Town’s Geographic Information System (GIS) coverage, the most recent version of the US Geological Survey 1:24,000 scale (7.5 minute) topographic map, or the soils map in the US Department of Agriculture Orange County Soil Survey and shall be subject to field verification by the Town of Chapel Hill Engineering Department. The most current versions of the following documents shall be used to classify streams within the Planning Jurisdiction of the Town of Chapel Hill: (1) North Carolina Division of Water Quality “Stream Classification Form and Internal Guidance Manual” and (2) Town of Chapel Hill “Field Procedures for Classification of Streams”.”
Section 3. This ordinance shall become effective November 11, 2003.
This the 10th day of November, 2003.
A resolution REGARDING THE VALIDITY PERIOD FOR STREAM DETERMINATIONS PERFORMED BY tOWN STAFF and regarding Town Manager review of stream determinations WITHIN THE TOWN’S PLANNING JURISDICTION (2003-11-10/R-9)
Whereas, the Council desires to enact revised stream definitions and verification criteria in the Chapel Hill Land Use Management Ordinance and to adopt related policy recommendations of the Technical Advisory Committee; and
WHEREAS, the Council desires to adopt the State of North Carolina Department of Environment and Natural Resources, Division of Water Quality “Stream Classification Form and Internal Guidance Manual” and the Town of Chapel Hill “Field Procedures for Classification of Streams” for use in determining the classification of streams and stream segments within the Town’s Planning Jurisdiction; and
WHEREAS, the Council desires to adopt a policy that stream determinations remain valid for a period of five years, unless changes in the watershed result in significant alteration of the characteristics of the stream such that a new determination is warranted; and
WHEREAS, the Council desires that the Town Manager, when circumstances warrant, solicit an advisory opinion from one or more experienced professionals when responding to appeals of stream determinations and related issues.
Now, therefore, be it resolved by the Council of the Town of Chapel Hill that the Council herewith establishes a five year validity period for all stream determinations performed by Town staff within the Town’s Planning Jurisdiction before a re-determination request will be considered, unless the stream characteristics are significantly altered as a result of changes in the watershed to the extent that a re-determination in less than five years is warranted.
BE IT FURTHER RESOLVED that the Council directs the Manager, in making a determination regarding the classification of any stream pursuant to Section 3.6.3 of the Land Use Management Ordinance, to consider the analysis presented to him by any interested party. Where the analyses presented by any party or parties and Town Staff indicate substantial conflicting evidence regarding the proper stream classification, the Manager may consult one or more independent persons with training and expertise in stream classification issues prior to making a final administrative decision. The Manager shall make a written report to the Council of any advice received as a result of such consultation.
BE IT FURTHER RESOLVED that the Council directs the Manager to report back to the Council within one year regarding the effectiveness of the policies and language revisions described herein and in the accompanying Ordinance.
This the 10th day of November, 2003.