This ongoing project inventories the 90 reaches of Lewis Creek for riparian and stream channel characteristics. WQ sampling, restoration plans, and land conservation plans utilize this information to guide and prioritize LCA projects. Please contact LCA to learn more about this work or to participate in seasonal field work.Overall, the results of the Phase 1 and limited Phase 2 efforts suggest that Lewis Creek is a relatively stable watershed (maximum impact rating of 14 out of a possible 32).   Seventy-four of the 80 reaches (92%) assessed in Phase 1 had impact ratings below 10.  Instabilities appear to be localized (e.g., in response to channelization to support/sustain agricultural activities or encroachment by roads or animal crossings) rather than system-wide. 

Uses for Geomorphic Data 

The geomorphic database (and the stream assessment process itself which yielded this data) is an important resource and tool to support the broader basin planning process.   The various stakeholders involved in watershed management will have different priorities for use of this data – given their missions, charters, goals, needs, available resources, and constraints.   VTDEC/FWD has suggested some specific applications for this database and even an order of priority (p. 9 of the draft Summary Report) which reflects their Agency’s position. 

The geomorphic stream assessment process enhances our ability to meet all of these objectives.  It can broaden our understanding of water quality trends and patterns, which will in turn help us to understand the present level of in-stream aquatic biodiversity and support future efforts to restore biodiversity. Results of the geomorphic assessment can be used by the member communities to optimally manage roads and infrastructure in ways which are more cost effective and in concert with natural stream dynamics.  Stream geomorphic assessments can also enhance our ability to optimally manage land uses to sustain desired agricultural, fisheries, and forestry land uses while minimizing sedimentation of Lewis Creek, its tributaries, and Lake Champlain.

1) Direct Application / Incorporation of Geomorphic Data in Ongoing LCA Projects 

We can use the Phase 1 and 2 stream assessment results to prioritize reaches for further geomorphic and habitat assessment to support: 

Community Planning and Zoning 

Incorporate the geomorph data as a “natural resource” layer in the new build-out analysis program to enhance our understanding of the consequences of various zoning decisions and /or build out scenarios. LCA and towns can then, for example, identify the tax base or other consequences of: 

a.     placing conservation easements on certain geomorphically valuable parcels;

b.     increasing buffers along and near geomorphically sensitive reaches;

c.     adjusting zoning densities, planning standards/mechanisms (e.g., % imperviousness, promoting clustering), and buffers  to minimize hydraulic stresses imparted by development  draining to reaches with incipient geomorphic instability;

d.     conducting geomorphic assessment recommendations for all agriculture, forestry, and fish and wildlife land managements plans before additional public investments are granted and/or land use changes occur. 

Share this new information and survey watershed citizens and town groups to get community feedback, identify community values and needs, and adapt LCA community service projects accordingly.

Conservation Objectives 

Identify and prioritize reaches to target for future conservation.  LCA and VTDEC/FWD have identified some conservation sites, and it is likely that other reaches will fall out of future Phase 2 & 3 efforts.  

Use of the geomorphic data in combination with important wildlife habitat or natural communities data can result in a more comprehensive approach to prioritizing parcels for conservation. The geomorphic data will provide additional technical justification for why a given parcel should be conserved.   This is an opportunity for education and outreach directed to neighboring conservation organizations and the Vermont Rivers Conservancy.

Community Infrastructure Maintenance  

Water Quality Monitoring Programs

With regard to its historic phosphorus, E. coli, and temperature monitoring program, LCA will continue compiling the existing data into GIS.  This will facilitate a review of the spatial and temporal trends in water quality.  These trends may correlate with high-impact ratings (identified from Phase 1) or geomorphically unstable reaches (identified in Phase 2), and we can determine if historic sampling locations adequately monitor to meet the specific objectives of LCA.  Specific reaches can be targeted for further study which would likely involve more geomorphic assessments (Phase 2 and 3) and more elaborate water quality monitoring.   These research efforts would be time and resource intensive; therefore, LCA may simply want to identify research needs for further study and then co-sponsor or host the research efforts in partnership with academia and/or private consultants.   

  Examples of evaluations which could be undertaken (depending on the organization’s priorities) include:

a.   Identify and prioritize reaches which we hypothesize may be contributing phosphorus and sediments due to stream reach instabilities and target these for further study. 

b.   Look for correlations between temperature and canopy cover / width of riparian zones, etc.

c.   Overlay the municipal infrastructure layer (e.g., culverts, drainage ditches) on the geomorph impact rating data on the GIS.  (Phase 1 section 5-2, 11/1/01 draft).  This process may highlight specific structures and/or road maintenance practices which have contributed to stream reach instability (e.g., aggradation) which in turn may have led to degradation of water quality and aquatic biodiversity.  Fold in the LCA/NRCS data collected since 1995 to assess where road maintenance and culvert / bridge maintenance practices may have contributed to accelerated aggradation and/or other adjustment processes.  Consider monitoring suspended sediments, % embeddedness, and/or conduct pebble counts upstream and downstream of target reaches to assess current conditions (baseline) and monitor effectiveness of altered road maintenance procedures.  More demonstration projects to assess effectiveness of these Best Management Practices would be timely. 

From these reviews and further study, we could determine and prioritize which restoration and/or management activities should be undertaken to minimize or reverse impacts to water quality. 

Education and Outreach 

To help other stakeholders recognize the value of the geomorphic assessments and to identify uses and priorities for collecting additional geomorphic data, LCA could: 

a.   Bring the geomorphic database and stream assessment process to the attention of town road crews, town and regional planning/ zoning, State and federal agencies, environmental groups, agricultural groups, etc to demonstrate how this data can been collectively useful when identifying and prioritizing water quality improvement plans in Vermont watershed towns.

b.   Train and assist other stakeholders in conducting further Phase 2 and Phase 3 assessments necessary to meet their particular project objectives.

c.   Continue to support VTDEC/FWD efforts to update and automate Phase 1, 2, & 3 protocols and build a database of reference reach data to support the development of VT’s Hydraulic Geometry Curves.

d.   Reach out to other watershed groups to provide training and support as they conduct stream assessments in their watersheds.

e.   Educate land trusts and conservation organizations to help them understand the greater value of conserving stream reaches with geomorphic significance – such as reference reaches and reaches with high potential for developing instability under development pressure.

f.     Identify important natural communities research (ongoing) in the riparian corridor while considering streambank restoration plans. 

LCA Geomorphic and Habitat Assessment Project

This ongoing project inventories the 90 reaches of Lewis Creek for riparian and stream channel characteristics. Water quality sampling, restoration plans, and land conservation plans utilize this information to guide and prioritize LCA projects. Please contact LCA to learn more about this work or to participate in seasonal field work.

Overall, the results of the Phase 1 and limited Phase 2 efforts suggest that Lewis Creek is a relatively stable watershed (maximum impact rating of 14 out of a possible 32).   Seventy-four of the 80 reaches (92%) assessed in Phase 1 had impact ratings below 10.  Instabilities appear to be localized (e.g., in response to channelization to support/sustain agricultural activities or encroachment by roads or animal crossings) rather than system-wide.  

Having said this, it is important to recognize that the amount of data collected so far for the watershed is limited.  Only 12 out of 80 reaches (15%) have been assessed in Phase 2 and only three reaches went to Phase 3. 

Uses for Geomorphic Data 

The geomorphic database (and the stream assessment process itself which yielded this data) is an important resource and tool to support the broader basin planning process.   The various stakeholders involved in watershed management will have different priorities for use of this data – given their missions, charters, goals, needs, available resources, and constraints.   VTDEC/FWD has suggested some specific applications for this database and even an order of priority (p. 9 of the draft Summary Report) which reflects their Agency’s position. 

The geomorphic stream assessment process enhances our ability to meet all of these objectives.  It can broaden our understanding of water quality trends and patterns, which will in turn help us to understand the present level of in-stream aquatic biodiversity and support future efforts to restore biodiversity. Results of the geomorphic assessment can be used by the member communities to optimally manage roads and infrastructure in ways which are more cost effective and in concert with natural stream dynamics.  Stream geomorphic assessments can also enhance our ability to optimally manage land uses to sustain desired agricultural, fisheries, and forestry land uses while minimizing sedimentation of Lewis Creek, its tributaries, and Lake Champlain.

We can use the Phase 1 and 2 stream assessment results to prioritize reaches for further geomorphic and habitat assessment to support: 

Community Planning and Zoning 

Incorporate the geomorph data as a “natural resource” layer in the new build-out analysis program to enhance our understanding of the consequences of various zoning decisions and /or build out scenarios. LCA and towns can then, for example, identify the tax base or other consequences of: 

a.     placing conservation easements on certain geomorphically valuable parcels;

b.     increasing buffers along and near geomorphically sensitive reaches;

c.     adjusting zoning densities, planning standards/mechanisms (e.g., % imperviousness, promoting clustering), and buffers  to minimize hydraulic stresses imparted by   

       development  draining to reaches with incipient geomorphic instability;

d.     conducting geomorphic assessment recommendations for all agriculture, forestry, and fish and wildlife land managements plans before additional public investments

       are granted and/or land use changes occur. 

Share this new information and survey watershed citizens and town groups to get community feedback, identify community values and needs, and adapt LCA community service projects accordingly.

Conservation

Identify and prioritize reaches to target for future conservation.  LCA and VTDEC/FWD have identified some conservation sites, and it is likely that other reaches will fall out of future Phase 2 & 3 efforts.  

Use of the geomorphic data in combination with important wildlife habitat or natural communities data can result in a more comprehensive approach to prioritizing parcels for conservation. The geomorphic data will provide additional technical justification for why a given parcel should be conserved.   This is an opportunity for education and outreach directed to neighboring conservation organizations and the Vermont Rivers Conservancy.

Community Infrastructure Maintenance

Identify unstable reaches which are impacting infrastructure.  Work with experts and the community to identify restoration options for the stream or alternate construction/ management options for the roads, culverts, bridges that will result in reduced impacts to the stream and reduced long term costs to towns. 

While there have been no substantial infrastructure losses due to channel instabilities and planform changes; some road maintenance, culverts, bridges, and insufficient road shoulders are believed to contribute to accelerated aggradation of Lewis Creek. LCA is currently working with NRCS in this area and the geomorphic data can provide meaningful information as LCA and others consider river monitoring plans to support sedimentation reduction strategies.