HomeMy WebLinkAboutCOUNCIL - AGENDA ITEM - 03/16/2010 - ITEMS RELATING TO A REVIEW OF THE CITY'S STORMWATE DATE: March 16, 2010 AGENDA ITEM SUMMARY
STAFF: Jon Haukaas
Brian Janonis -
T COLLINS CITY COUNCIL
Items Relating to a Review of the City's Stormwater Management Program.
A. First Reading of Ordinance No. 030, 2010 Amending Section 26-492 of the Code Declaring the Purpose of
the Stormwater Utility.
B. First Reading of Ordinance No. 031, 2010 Adopting Landscape Design Standards and Guidelines as an
Addendum to the City's Storm Drainage Design Criteria and Construction Standards.
EXECUTIVE SUMMARY
These Ordinances adopt revised stormwater purpose statement and new landscape design standards and guidelines
for stormwater and detention facilities. The revised purpose statement was expanded to include a balanced approach
to the triple bottom line components of economic,environmental,and social aspects of stormwater management. The
landscape design standards and guidelines were developed to provide direction to improve stormwater quality and
aesthetics of stormwater facilities.
BACKGROUND / DISCUSSION
In October 2008, Council directed staff to review the City's stormwater program. At the December 8, 2009 Work
Session, staff and the City's Water Board discussed the program with Council. At this work session Council directed
staff to present items for Council consideration as they were ready for formal consideration. These items are the first
two elements in a number of items that will be presented to Council over the next few months, aimed at achieving a
new emphasis and purpose for the Stormwater Utility that recognizes an integrated and multi-functional approach to
stormwater management in the City of Fort Collins.
The Stormwater program purpose statement is recommended to be revised to reflect the 21 st Century Utility Initiative
and provide an expanded triple bottom line emphasis. The new purpose statement places a balanced emphasis on
the economic, environmental and social components, developing a holistic and integrated program that focuses on
the benefits of the triple bottom line.
Council discussed the recommended purpose statement from the Water Board at its December 2009 work session
and directed staff to make revisions to the Water Board's proposed purpose statement. Following is the proposed
purpose statement which incorporates the revisions recommended by Council:
The City's integrated, sustainable stormwater management program shall reflect the community's
values of protecting and restoring the City's watersheds,its tributaries and the Cache la Poudre River
for mutual economic, social, and environmental benefits including:
• Economic: flood damage reduction, increased recreation and tourism along stream
corridors, reduced business interruptions
• Social: public safety and welfare,reduced need foremergency response,recreation
opportunities promoting community wellness
• Environmental: preserve natural and beneficial functions of floodplains,enhance stormwater
quality, preserve riparian habitat
The City of Fort Collins"Landscape Design Standards and Guidelines for Stormwater and Detention Facilities"will
facilitate the infiltration of runoff, enhancing stormwater quality, increasing habitat value and plant conservation, and
increase the aesthetic appeal of detention facilities.
March 16, 2010 -2- ITEM 17
FINANCIAL IMPACT
Adoption of these Ordinances is not expected to have any significant financial impact on the City's budget or reserves.
It may lead to higher initial costs for development which will be offset by lower life-cycle costs, through reduced
maintenance and replacement costs and higher property values.
SUSTAINABILITY: ECONOMIC, ENVIRONMENTAL AND SOCIAL IMPACTS
Stormwater Purpose Statement
Economic Impacts
1. Increased opportunities to developing stormwater projects and facilities as urban amenities as open space,
riparian corridors and multi-use facilities.
2. Reduced costs of flood events in regard to structure and content damage, transportation obstructions,
infrastructure repair and emergency response.
Environmental Impacts
1. Increased environmental ethos through improving stormwater quality, stream restoration and habitat
protection.
2. Reduced damage of flood events from raw sewage overflows, mold disease and solid waste disposal.
Social Impacts
1. Increased opportunities related to public recreation and education, i.e., pedestrian corridors, outdoor class
rooms, water quality treatment demonstration projects.
2. Reduced impacts from flood events, loss of life, personnel injury and emotional trauma.
Landscape Design Standards and Guidelines for Stormwater and Detention Facilities
Economic Impacts
1. More sustainable development regulations will reduce life-cycle costs of operating and maintaining detention
facilities, through lower watering and maintenance costs.
2. Less erosion and flooding damages incurred from smaller storms due to higher infiltration capacity of
detention ponds.
3. If not properly built and maintained will lead to loss of installed vegetation, erosion threats and ultimately loss
of initial investment.
4. Higher initial investment costs for landscaping of new development projects could discourage development.
Environmental Impacts
1. Higher water quality in streams and water bodies receiving stormwater from detention ponds through
increased filtration of pollutants, increased evapotranspiration effects and reduced stream degradation and
erosion.
2. Less use of resources for irrigation, heating and cooling needs and land consumption.
3. Improved habitat value for flora and fauna.
4. If not properly designed, built or maintained could lead to stagnant water conditions, nuisance odors, and
create a mosquito breeding area.
Social Impacts
1. Will improve aesthetics in public spaces due to the increased vegetation requirements and standards.
2. Can serve an educational function as outdoor classrooms scattered within the community.
3. More opportunities for recreation and enjoyment of public spaces through the construction of multi-purpose
facilities.
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March 16, 2010 -3- ITEM 17
STAFF RECOMMENDATION
Staff recommends adoption of the Ordinances on First Reading.
BOARD / COMMISSION RECOMMENDATION
At its November 2008 meeting, the Water Board unanimously recommended adoption of revised purpose statement
for the stormwater program. The Water Board's purpose statement, as amended by Council, was reviewed by the
Water Board at its January 2010 meeting with no additional comments and no additional revisions.
The Water Board reviewed the detention pond landscape standards and guidelines at its June 2009 and November
2009 meetings. A unanimous recommendation for adoption was made at the November meeting.
The Planning and Zoning Board reviewed the draft standards and guidelines as an informational item at its February
2010 work session and offered positive feedback and expressions of support.
PUBLIC OUTREACH
These standards and guidelines have gone through a significant amount of outreach activities and efforts in order to
solicit and receive comments on the proposed standards and guidelines. The outreach was done through a
combination of stakeholder group meetings and public meetings. The stakeholder group consisted of members of
the development community,design professionals, and maintenance professionals. An open house was held in April
2009, with 50 people attending. From that first open house and the initial stakeholder meeting, comments were
gathered and incorporated into the revised draft.
The revised draft standards and guidelines then went through a second round of outreach in August 2009, going to
both the stakeholder group and the general public at an open house and then to the Water Board for comments and
recommendation. The Fort Collins Chamber of Commerce Local Legislative Affairs Committee raised concerns on
the increased costs and increased land area required to meet the new requirements.
ATTACHMENTS
1. City Council Work Session Summary, December 8, 2009
2. Water Board Recommendation Memo and Meeting Excerpts
ATTACHMENT 1
Utilities Executive Director
Ci$�/y ®� electric• storrnwater• wastewater. water
700 Wood St.
Fort Collins PO Box 560
Fort Collins,CO 80522
970.41 . 0
970.416.222208
970.224.6003 TDD
utilities®fcoov.com
fcgov.com/utifi8es
MEMORANDUM
Date: December 10, 2009
To: Mayor Hutchinson and City Council members
Through: Darin Atteberry, City Manager
Brian Janonis, Utilities Executive Director�}
From: Jon Haukaas, Water Engineering and Field Operations Manager
Reference: December 8, 2009 Work Session Summary—Stormwater Program Review
Brian Janonis, Utilities Executive Director and Jon Haukaas, Water Engineering and Field
Operations Manager, presented Council with a brief overview of the work done to date on the
Stormwater Program Review. Council members present included Mayor Doug Hutchinson,
Mayor Pro Tern Kelly Ohlson, David Roy, Lisa Poppaw and Aislinn Kottwitz.
Council members reviewed and discussed materials provided and offered feedback on nine (9)
key questions. Key discussion and feed-back by Council:
1. Purpose Statement
Council supports a change to the language to include specific examples of the three Triple
Bottom Line components: economic, social and environmental. This will allow a balance of
all three components.
Two Council members requested that wildlife habitat be mentioned rather than natural areas.
Remove the preamble of"The City Council finds, determines and declares" and simply begin
statement with "The City's integrated..."
2. Best Management Practices (BMP) Policy Update
Council supports pursuing the five recommendations of the BMP report. Clarification was
given by staff of the difference between the Watershed Management Team and the Citizen
Advisory Board. The former will be made up of staff from various City departments. The
Advisory Board may be made up of appointed citizens, perhaps members of existing Boards
and a representative from Colorado State University, who may then oversee the policy issues
carried out by the Management Team.
City of
F6rt Collins
3. Investigate a New Cost Share System
Several Council members expressed concern that a small group receives benefits from
projects paid for by all the citizens, for example, undeveloped properties.
It was also pointed out that having an even rate across the city is fair since flood protection
can be equated to fire and police protection.
There is support from Council to investigate this issue further. There is some concern about
the amount of staff time this will take; therefore, staff will prepare a scope of work and a
timeline for Council's consideration.
4. Fund Stream Restoration Projects with Stormwater Funds
This is supported, as long as the restoration is clearly for stormwater purposes. Since the
extent of the expenditures is unknown;it's difficult to provide detailed direction now.
When the master plans are updated, they will include recommended stream restoration
projects and their costs. Council will have the opportunity to review the master plans as well
as a revised financial plan which includes stream restoration costs.
5. Poudre River Floodplain Regulations LOMR-Fills
This change closes a loop hole in the current regulations and provides staff the authority to
not sign LOMR-Fill applications over FEMA's decision. Council supports investigating this
further and bringing back code language changes for their consideration.
6. Poudre River Floodplain Regulations—Change 0.5 ft. Floodway to 0.1 ft. Floodway
Council supports further investigation of this change.
There is support for restricting development in the floodplain, but further information is
needed. There is also concern about why the City would want to change something that was
put in place only two years ago. Is it good governance to make a major change so soon?
What is the County's opinion? What is the history behind the 2007 regulation change?
Staff will provide the history of the 2007 change, and prepare a scope of work and timeline
for this investigation for Council information.
7. Poudre River Floodplain Regulations—Restrict All Structures in the Floodplain
Council supports further study of this regulation change. This work will take place in 2010,
but does not need to be done on the exact timeline as the City Plan update. Staff will prepare
a scope of work and timeline for the investigation for Council's information.
8. Update Master Plans Using a Triple Bottom Line Anal
Council supports this. Staff will explain the scope and process to accomplish this as well as
prepare a timeline for completion. Work will begin in 2010.
Page 2 of 3
City of
Fort Collins
9. Adoption of Landscape Design Standards and Guidelines for Stormwater and Detention
Ponds
Council supports adoption of the standards and guidelines. Staff will move forward with the
adoption process.
Staff will continue with the programs implemented to date, and begin the research and public
education on the additional components being considered.
Staff will prepare the information requested by the City Council to include:
- The cost of Stormwater Capital Projects dating back to 1995.
- A scope and timeline for each component of the Stormwater Repurposing effort.
- Agenda items for approval and final action by the City Council as they are completed.
ATTACHMENT 2
utilities—water Boer
City of 700 wood 0
Fait Fort Collins
PO6ox58rt Collins,CO 80522
970.221.6702
9 -lax
tcgov.comgov.com
MEMORANDUM
DATE: November 23, 2009
TO: Mayor Doug Hutchinson and City Council Members
FROM: Gina C. Janett,Water Board Chairperson I,--
CC: Brian Janonis, Utilities Executive Director
RE: Water Board Recommendations concerning Stormwater Re-Purposing
Over the past year,the Water Board has spent many hours reviewing documents and hearing
presentations from staff on the stormwater repurposing review. We have also conducted a work
session to allow for detailed Board discussions before preparing our recommendations, below. I
have numbered the Board's recommendations continuously to make it easier for discussion.
I look forward to attending your Work Session on December 8`h when this issue is discussed by
Council.
A. Stormwater Purpose Statement
One year ago, the WB reviewed the existing Stormwater Purpose Statement and after discussion
unanimously approved the following as our recommendation to Council:
"The City Council hereby finds, determines and declares the City's integrated
stormwater management program is for the mutual economic, social and environmental
benefits of public safety,flood mitigation, water quality and public welfare while
protecting natural areas and their features, protecting and restoring the City's
watersheds, its tributaries and the Cache la Poudre River."
During discussion of the purpose statement,board members indicated that while the top goal for
the stormwater program is to protect public safety that it was also desirable to protect and restore
the City's watersheds, floodplains and riparian areas for the purposes of protecting water quality,
reducing the risks of flooding, and restoring and enhancing the ecology of the river, natural areas
and wildlife habitat.
The Board agreed that a more balanced approach would include benefits to environmental and
social values as well as to economic ones. The current program seems designed to mostly benefit
property owners and economic values rather than environmental ones. The Board supports the
change to a"triple bottom line" approach.
.Cfty of
o
B. Best Management Policy/Practices Update (LID,Watershed Planning)
Over the past year, the utilities staff did a great job of walking the Board through the many
complicated components of public stormwater policies and regulations under review.They
provided many documents and presentations to bring us up to speed on existing and proposed
changes before we made our recommendations. The Board is very supportive of the city moving
forward on watershed planning and implementation of Best Management Practices.
In April the Board voted unanimously to support a motion stating:
"In order to improve the Stormwater Water Quality Program, the Water Board supports
all five recommendations as stated,provided staff returns to the Board with a
recommendation for the multi-disciplinary watershed planning group."
The five recommendations were that the city:
• Form a citizen review group for the watershed team.
• Complete Master Plan updates (sub-watershed restoration plans)that define the
BMPs (including LID techniques)that should be used in order to protect and restore
the chemical, physical and biological attributes of each stream within each drainage
basin (note that this will require updating of engineering criteria).
• Form a watershed planning team led by a planning coordinator(s).
• Revise timelines and budgets for implementation of each Master Plan.
• Formalize coordinated long term monitoring programs to provide feedback to the
watershed team in order to track progress.
During the discussion, the board requested more information on the make-up of the citizen
committee and whether it would be an "ad hoc"group or on-going board or committee and if it
would be the Water Board or a new multi-disciplinary committee made up of representatives
from various existing boards (e.g. Natural Resources, Land Conservation and Stewardship, Parks
and Recreation,etc.) Staff indicated the committee make-up would be brought back later for
discussion.
The above recommendations are encouraged to be a part of the City Plan update.
C. Landscape Design Standards and Guidelines for Stormwater and Detention Facilities
The Water Board reviewed the draft document before and after the stakeholders and public
outreach meetings. The Board made several recommendations that were added to the staff
document and included in the final draft. These included changing the name to"Guidelines and
Standards" to properly signal that some of the contents are advisory in nature (guidelines) while
others are mandatory (standards). The staff then added an appeals/variance process in order to
provide applicants with some flexibility in their detention pond design.
The Board voted unanimously to recommend that Council adopt the final draft.
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Fort Collins
D.Stormwater Master Plans/Level of Protection
The item that garnered the most discussion by the Board and which dominated both a special
work session in September and the regular October meeting was the Stormwater Master Plans
and the methodology for choosing projects to be constructed. It was acknowledged that the large
debt that Stormwater is paying off is for the purpose of constructing expensive capital projects
and that debt service and the master plans were driving the rates. The board acknowledged that
Fort Collins rates are higher than most along the Front Range and that the only way to affect
rates was to focus on changing the Master Plan selection and project design review criteria.
The current system uses a Benefit/Cost ratio for selecting and prioritizing projects. The Board
found that this methodology does not adequately include environmental or social costs or
benefits, particularly those which cannot be quantified in dollars and cents. The value of
preserving or restoring natural water quality features of a stream or floodplain, for example, are
not currently used as a criteria to select or design stormwater projects.
Additionally, Board members suggested that the Benefit/Cost ratios used to select a project were
too low, for example, some members think a 1:1.1 ratio isn't sufficient benefit to build a costly
project: Board members also discussed whether these secondary, non-economic benefits/costs
should be quantified and added into the Benefit/Cost analysis or whether there should be a new
methodology used that adds qualitative criteria to the analysis in addition to the B/C analysis.
As a result of these discussions, the Board approved the following motions:
1. The Board recommends to City Council that staff change to using the triple bottom line(TBL)
philosophy of social, economic, and environmental components to determine flood control and
stream enhancement projects. lit this scenario, the numeric B-C ratio plays a smaller role in
determining capital projects and projects can be recommended based on factors without a
numerical value. (Vote: 9 Yeas, 1 Nay—Connor who was concerned that the "what" and "how"
of analysis were mixed together and not clear)
2. The Board recommends to City Council that staff should research appropriate and applicable
methodologies for evaluating the social and environmental impacts, both positive and negative,
of capital projects. (Vote unanimous in favor)
d. The Board recommends to City Council that staff should evaluate the B-C ratio criteria as a
part of the TBL approach. (Vote unanimous in favor)
The discussion then proceeded to the issue of the Level of Protection that should be used when
either the City or private property owners build. Under this discussion,there were concerns
noted by multiple board members that the rate payers are paying high rates with an over
emphasis on protecting property in addition to the primary goal of protecting public safety. The
sentiment was stated that people who buy land in a floodplain know they are in a floodplain and
that it is unfair for the rate payers to bear the high public costs of private decisions to locate in a
floodplain and be at risk for flooding. Additionally, it was noted that people who own property
in floodplains are required to buy flood insurance and are reimbursed for some of their flood
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damages to property. As such, some Board members did not think it was the government's job
to build expensive capital projects to protect private property.
The resulting motion, which failed for various reasons, was:
4. The Water Board recommends to City Council that guidelines to use for Level of Protection
when making capital construction decisions are based on high flow events. This represents a
change, because it places less emphasis on the weighting of property damage. (Vote: 9 Nays, 1
Yea)
Most of the Board members indicated they voted"nay"because they are satisfied with the
requirement to build to a 100-year Level of Protection. Board Member Wockner voted "nay"
because he thinks this issue will be covered by previous motions and the TPL philosophy. Board
Member Conner voted "nay" because he would like to define a specific Level of Protection.
The Board also discussed the issue of funding stream corridor enhancements from stormwater
user fees. The recommendation that passed was:
S. The Board recommends to City Council that partial or entire stream corridor enhancements
can be funded by the Stormwater Capital Improvement Program based on prioritization through
the TBL analysis. (Vote: Unanimous in favor)
Finally, the board discussed the issue of cost sharing between the city and private property
owners for capital projects that reduce the size of a floodplain, thus, "removing property" from
the floodplain. The common description is that a property or structure is removed from a
floodplain when, in reality, the property doesn't move outside of the floodplain, the capital
project makes the floodplain smaller. Board members consider this an undeserved benefit to a
property owner that is paid for by all rate payers. It was acknowledged that developing a cost
sharing methodology might be difficult, but that it was a worthy goal.
6. The Board recommends to City Council that a new cost share method for properties removed
from the floodplain by a City capital project be created to reflect a portion of the benefit to that
property. (Vote: Unanimous in favor)
E.Stormwater Utility Fees
The Board acknowledged that it is difficult to make a recommendation on what the monthly fees
should be until after the Council deliberates on the TBL approach to Master Planning. The
following recommendations were then made concerning fees and Stormwater Capital Project
Investments:
7. The Board recommends to City Council that stormwater monthly fees be revisited following
the completion of the Stormwater Master Plan update. (Vote: Unanimous in favor)
8. The board recommends to City Council that Capital Project Investment be reduced to pay off
existing debt more quickly and staff do an analysis of what a realistic level of additional early
pay-off would be. (Vote - Motion Failed. 6 NAYs, 4 YAYs)
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City,of
Four members voting"nay" indicated that it's not up to the Board to tell the City how to spend
its money. Another member voting Nay wanted to wait until the Master Plans are updated
before determining whether its time to reduce the debt. And the last"nay" vote was because the
member thought the City should have flexibility for using funds, especially for unknown events
in the future.
F.Floodplain Regulations
The city's floodplain regulations are very detailed and complex and have been modified multiple
times over the years. The Board chose to narrow its focus to several items of concern.
Under our current city rules, new residential and mixed use structures are not allowed in the 100-
year floodplain fringe of the Poudre River. This requirement was adopted for public safety
purposes to protect residents, especially while sleeping, in the event of a flood. Currently,
builders wishing to construct residential or mixed use structures in the floodplain can use a
loophole in city regulations that allows them to submit a Letter of Map Revision based on fill
(LOMR-Fill)to FEMA. This loophole also allows the property owner to avoid flood insurance.
The Board discussed the dangers of allowing residential units in the floodplain and the issue of
allowing fill that would push the water elsewhere in the floodplain. The board voted
unanimously to recommend removing this loophole.
9. The Board recommends to City Council the Poudre River floodplain regulations b e revised to
not allow residential or mixed use structural development on LOMR-Fills. (Vote: Unanimous in
favor)
The Board then discussed the advisability of allowing any structures, commercial or other in the
Poudre River floodplain fringe. While the public safety exposure of sleeping residents might not
be a problem with commercial structures, some board members were still concerned that any
structures in the floodplain are at risk. The Chair mentioned the Army Corps of Engineers' and
FEMA's efforts over the years to preserve and restore the natural and beneficial values served by
floodplains which include natural moderation of floods, water quality maintenance and
groundwater recharge. She also noted that the Corps does not generally grant a fill permit when
a project will fill an existing 100-year floodplain to increase developable land.
It was acknowledged by board members that prohibiting all structures in the Poudre floodplain
might include bridges, trails, and other structures as well as commercial buildings and that the
impacts of such a change to the regulations would impact multiple landowners and would likely
require public outreach. After much discussion, the following motion was made which passed
unanimously.
2. The Board recommends to City Council that the Poudre River floodplain regulations be
studied to not allow structures in the 100-year floodplain. (Vote: Unanimous in favor)
The final floodplain regulation the board reviewed was the issue of the amount of Poudre River
floodway rise that could be allowed. City regulations used to allow only a 0.1 foot rise in water
in the floodway as a result of fill being placed in the floodplain. In 2007, the Council changed
the rise to the higher value of 0.5' in an effort to compromise with the County to reach
comparable floodplain regulations.
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Fort Collins
The issue was brought up again because of the stormwater repurposing effort. The effect of the
2007 increase in the allowable flood rise value allows fill that reduces the width and carrying
capacity of the floodplain. Staff explained that the wider the floodplain, the greater the benefits
from preserving the natural and beneficial functions of the floodway and fringe. A wide
floodplain better preserves the health of the riparian zone, allowing smaller sized particles to
flow onto the fringe, leaving the channel clearer and coarser for high flow events. Reducing the
floodplain by allowing a higher floodway rise confines the river and allows flood waters to flow
more rapidly through town, tending to do more damage to bridges and banks and posing a
greater threat to public safety.
While staff favors a possible change back to the 0.1 foot floodway rise requirement, they
acknowledged that it would require some compromises be made. The board members indicated
support for returning the regulations back to the 0.1 foot flood rise in order to better protect the
river floodplain and to preserve its natural functions.
3. The Board recommends to City Council the Poudre River Floodplain regulations be revised to
adopt a 0.1 foot rise floodway. (Vote: 6 Yeas, 2 Nays)
Board members voting Nay did not wish to see the regulations change every two years or so and
one member stated he voted for it in 2006 and did not wish to change his vote now.
The Water Board appreciates the Council's interest and time to study the comprehensive re-
purposing of the Stormwater policies and regulations. I will be at the Work Session to answer
any questions the Council may have on our recommendations.
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Excerpt from Water Board 11 20 08 Approved Minutes
Stormwater Programn Statement
At the October 14, 2008 Work Session, Council indicated the Stormwater program
needed a new mission statement to reflect a 2 1" Century Utility and a greater
environmental emphasis.
The existing purpose statement is in Sec. 26-492 of City Code. Staff produced several
draft purpose statements and presented the latest draft to the Water Board.
Recommended purpose statement:
"The City Council hereby finds, determines and declares the necessity of a
holistic stormwater management program to protect and restore the City's
watersheds, streams and the Cache la Poudre River for the mutual economic,
social, and environmental benefits of flood mitigation, public safety, water
quality, habitat protection and public welfare."
Staff asked Water Board for a recommendation to City Council, who will consider this
item on December 161".
Discussion:
The proposed purpose statement does not mention floodplain and riparian corridor
preservation?
While not mentioned specifically, the wording "protect and restore the City's ... streams
... for... environmental benefits (and) habitat protection" imply a very similar meaning.
Please keep in mind that this is a very broad and high level purpose statement. The finer
details of implementing this purpose statement will be considered by staff and City
Council (with input from Water Board) in the first quarter of 2009.
The statement uses the words 'Wood mitigation". Shouldn't we be trying to prevent
floods?
The City cannot prevent floods. We can however, reduce the risk. In that sense, mitigate
is a more accurate tern. We try to raise awareness and prefer to use the term"mitigate"
instead of"prevent", because floods cannot be prevented or predicted.
Does this statement reflect the desire of City Council?
Staff does believe the proposed statement reflects the desire of City Council. As
independent advisors to City Council, the Water Board certainly does not have to agree
with something just because they think it is what City Council wants.
After discussion and review of the various drafts provided by staff,Water Board
indicated a preference for the alternate statement#5 which reads:
"The City Council hereby finds, determines and declares the City's integrated
stormwater management program is for the mutual economic, social and
Water Board Minutes 1
November 20, 2008
environmental benefits of flood mitigation, public safety, water quality, habitat
protection and public welfare while being sensitive to natural areas and their
features, protects and restores the City's watersheds, its tributaries and the Cache
la Poudre River."
Motion: A motion was made that the Water Board recommend alternate#5 as
the statement of purpose for the Stormwater program.
Friendly Amendment:
Would like to remove"sensitive" and replace with "protect"and list public safety first
before flood mitigation.
Amended Motion: A motion was made that the Water Board recommend
alternate #5 with revisions as the statement of purpose for the Stormwater
program.
Friendly Amendment:
Would like to remove "habitat protection", because it also reads to protect natural areas
and its features.
The revised purpose statement for vote of the Water Board reads as follows:
"The City Council hereby finds, detennines and declares the City's integrated
stonnwater management program is for the mutual economic, social and
environmental benefits of public safety, flood mitigation, water quality and public
welfare while protecting natural areas and their features, protecting and restoring
the City's watersheds, its tributaries and the Cache la Poudre River."
Motion to recommend the revised purpose statement for Stormwater to Council.
A vote was taken, and it passed unanimously.
Water Board Minutes 2
November 20, 2008
Excerpt from Water Board 6 25 09 Approved Minutes
Stormwater Program Best Management Practice(BMP) Review
Basil Hamdan, Stormwater Engineer,presented the Detention Pond
Construction/Landscaping Guidelines and Low Impact Development(LID)
Demonstration Projects.
Detention Pond Construction/Landscaping Guidelines:
The following guidelines were developed to provide direction in the design and
construction of detention ponds and other drainage facilities. The purpose of the
guidelines is to facilitate infiltration of runoff and enhance stormwater quality, increase
habitat value and plant conservation while increasing aesthetic appeal.
Stormwater staff started with a public outreach process to obtain information and
comments regarding the guidelines. The process steps will include:
• Formation of a steering group consisting of other departments like Planning and
Natural Resources, as well as designers and consultants;
• Meeting with a stakeholders group of landscaping professionals and those who
maintain the detention ponds;
• Hosting a public open house for the community to share comments regarding the
� guidelines;
• Creating a draft document to encompass the main elements of the guidelines and
requirements;
• Sharing information with the Water Board;
• Conducting a second stakeholders meeting to gather reactions to the draft
document;
• Hosting a second public open house in July;
• Finalizing the document;
• Returning to the Water Board with an action item for recommendation in August;
and
• Presenting to City Council.
The guidelines contain the following recommendations:
• Disconnection of impervious surfaces;
• Encourage native planting to reduce irrigation needs for plantings to encourage
water conservation;
• Use of varied side slopes and undulating bottoms in detention ponds;
• Encourage multi-use facilities ponds to be used for purposes other than detention;
and
• Improve aesthetics which add dimension and value to the community.
Examples of desired pond construction throughout Fort Collins make use of a more
natural habitat with no cement drain pans, and the landscaping improves the aesthetics
and value of the area. Ponds which bring water quickly into the ponds by using cement
pans, concrete walls and lack of filtration are less desirable.
Water Board Minutes 1
June 25, 2009
Stormwater would like recommendations and comments from the Water Board after
reviewing the draft, so feedback can be incorporated into the final document.
Discussion:
What are the current standards.for development which call.for some type ofstormwater
construction?
The current standard is geared toward volume to handle flooding. Stormwater staff would
like to see requirements in place that are not just based on volume, but also consider a
sense of development and value in terms of landscape, aesthetics and accessibility.
Was there a cost analysis done on this for developments?
The information is based upon life cycle, not necessarily a cost analysis. The initial
investments represent the largest costs.
Is Parks represented on this committee?
These guidelines are geared toward private facilities, not necessarily public facilities.
Are these guidelines followed on the Canal Importation and Ponds Outfall(CIPO)
project?
These standards are being exceeded at CIPO. These guidelines are already being
followed in the public sector; we are asking for the private sector to follow these.
Are landscaping berms being discouraged?Berms cause water to move faster; is this
part of the plan?
This is a land use issue, and berms will be discussed this fall. They are not part of this
discussion.
Will this provide an incentive to reduce the volume of the ponds?
That is part of the LID discussion.
Is there anything about this approach to minimize the size?
The LID process addresses this. We are concentrating on use of open space.
Board Member Waskom believes that mosquitoes and West Nile Virus should be taken
into consideration. Staff noted wet areas are not required. Dry detention ponds that do not
involve standing water are an option.
Board Member Connor applauds the direction this is taking and would like to see the
final wording of the guidelines.
Vice Chairperson Balderson would like to see more work done on the maintenance
section of the draft document.
Water Board Minutes 2
June 25, 2009
Excerpt from Water Board 7 23.09 Approved Minutes
Stormwater Program Policy Review
Matt Fater, Special Projects Manager,presented an overview of the Stormwater Program
purpose statement. Last fall, Council requested a review of the purpose statement. Staff
solicited input from the Water Board, and the Board recommended an alternative
statement for Council's consideration and action (pending). Staff will present on the
repurposing of the program to Council in December.
The proposed Stormwater Program purpose statement as recommended by the Board is:
"The City Council hereby finds, determines and declares the City's integrated stormwater
management program is for the mutual economic, social and environmental benefits of
public safety, flood mitigation, water quality and public welfare while protecting natural
areas and their features, protecting and restoring the City's watersheds, its tributaries and
the Cache la Poudre River."
In regard to the guiding principles within the statement, Stormwater staff studied impacts
to determine how to effectively implement the intentions of the new purpose statement
and what direction to take the Stormwater Program., such as the effect of urbanization
and development on our watersheds and streams, irrigation and the introduction of
pollutants into storm drains.
Lack of protection from these impacts has resulted in loss of habitat, water pollution and
flood hazards. Staff are working toward solutions and following the triple bottom line
approach of balancing solutions between social, economic and environmental factors.
Enhancement opportunities related to recreation, education, connection with nature and
pedestrian corridors represent social benefits. A reduction in the negative social impacts
of flood events such as loss of life, personal injury and emotional trauma is also a
priority.
Economic benefits include opportunities to develop amenity projects such as open space,
riparian corridors and parks.
Environmental benefits are related to improvement of water quality, stream restoration
and habitat protection. The environmental damage of flood events from raw sewage
overflows,mold, disease and solid waste disposal is a priority.
Stormwater staff is taking an-integrated and holistic approach regarding land use,
education, engineering, ecology, construction and landscape design.
Staff will use the following concepts to achieve the goal of watershed protection:
• New development criteria;
• Erosion and sediment control;
• Pollution prevention; and
• Community education (K-12 and adult learning).
Water Board Minutes 1
July 23, 2009
Excerpt from Water Board 9.24 09 Approved Minutes
Detention Pond and Landscape Guidelines
(Refer to first five slides of presentation, available upon request).
Basil Hamdan, Stormwater Engineer, noted the board will be asked for a
recommendation on the Detention Pond and Landscape Guidelines at this meeting. The
information was originally presented at the June 25 meeting. The guidelines will also go
to the Planning and Zoning Board before adoption.
Discussion points:
• Some items in the draft guidelines represent the absolute minimum level of
steps needed to comply with the guidelines, and other items are actual
requirements.
• Flexibility is part of the process staff will use to work with property owners to
account for and work with site-specific conditions.
• Feedback from the public process and the boards will be incorporated into the
final document.
• The board suggested the title be changed to "Requirements and Guidelines" to
remove the sense that the guidelines are optional.
• Native grasses are encouraged in all applications, but can be varied when
necessary.
• Suppression of cattails was discussed.
• Active recreational areas can be multi-use, i.e. a playground with animal and
plant habitat. The developer is the party who pursues areas for recreational
use. The City can encourage designation for recreational areas in consulting
the Parks Master Plan.
• Board members asked staff to check on the difference between licensure
versus certification of landscape architects.
• The detention pond is designed at the time of building design. Staff have
previously had no authority to influence the process, but will serve as a
resource during the review under these new guidelines.
• All requirements will follow the recommendations of water conservation.
• Trickle channels may be looked at on a site-by-site basis.
Motion: Board Member Brown made a motion to revise the title to "Landscape
Design Standards and Guidelines" and support the direction staff is taking with
the work thus far on the detention landscaping. However, the Board wants to see
the final draft before they make a recommendation on these standards and
guidelines. Board Member Connor seconded the motion.
Discussion on the motion:
Guidelines will be presented to Council at a December or January work session, so staff
will bring the final draft of the guidelines back to the Board at the November 18 meeting.
Council's final approval of these guidelines will be part of their approval of the City Plan
update. The LID presentation concepts will also be incorporated into the final draft.
Water Board Minutes 1
September 24, 2009
Q: How does disconnection of impervious,areas (a LID component) relate? Removing
the pan will disconnect the areas. They support and compliment each other in achieving
infiltration.
Water Engineering and Field Services Manager Jon Haukaas recommended tabling this
until staff can bring a marked up version to the board.
A substitute motion to table this item was made by Board Member Waskom.
Board Member Gessler seconded the motion.
Vote on the substitute motion: 8 yeas, one nay (Connor).
Reason for nay vote: Board Member Connor doesn't see a reason to table it.
Water Board Minutes 2
September 24, 2009
Excerpt from Approved Water Board Minutes November 18 2009
Stormwater Program Review
Motion: Vice Chairperson Balderson moved that the Board notable the
Detention Pond Design and Landscape Standards from the September 2:and
meeting for the purpose of bringing them before the Board for discussio
action. Board Member Connor seconded the motion.
There was no discussion on the motion. Vote on the motion: It passed unanimously.
Chairperson 7anett introduced the topic by reminding the Board the Landscape
Guidelines had been reviewed at the September 24 meeting following the public outreach
process, but before the document was amended to include changes as a result of the
outreach. At that time, the Board decided to table the item and revisit it at the November
meeting, so the amendments were available for the Board's review.
Detention Pond Design and Landscape Standards Final Draft—Basil Hamdan,
Stormwater Engineer:
The final draft of the standards was presented to the Board and incorporates the latest
comments received during the Board's review at the September meeting, including a
change from "guidelines" to "standards" to indicate more clearly that these are not
optional in nature. An administrative variance procedure was added and a requirement for
landscape architects to be licensed was removed. Other minor changes were also made.
Board members asked for clarification on the following items:
• Wall height of 30 inches and placement of walls when terracing.
The 30 inches include finished wall area only.
• Low slopes. Staff would like to encourage disconnection from impervious
structures where possible.
• Adding four inches of topsoil over areas to be planted. Does `planted"
include drill seeding for disturbed areas? Seeding is required for all disturbed
areas. There are requirements for soil amendments currently within our
criteria.Does this apply to only the area within the top edge and below of the
detention or also the perimeter? It applies wherever planting will be done.
There are a number of sites where adding four inches of imported topsoil
would not be typical of the area, such as industrial sites. Topsoil can be
placed over the top of disturbed areas, such as utilities corridors. This creates
a different vegetation look. Where does this stop? This will be site-specific.
• Access when mowing; ruts form when mowing over moist soil. Grass plants
are offered as an option under guidelines; they are not a requirement. These
standards and guidelines provide a vision, while realizing some cases will
require flexibility.
How will tall grasses be handled? There could be an exemption from mowing
in low flow areas where wetland growth is encouraged. A City process for
1
designating a natural area through the Natural Resources department is also an
option.
Chairperson Janett noted the history of complaints in the community about the many
rounds ordinarily required to complete the development review process. Staff noted that
having these standards and guidelines in place should provide more guidance from the
outset of the development process and hopefully streamline the process.
Motion: Board Member Connor moved the Water Board recommends to City
Council approval of the Landscape Design Standards and Guidelines for
Stormwater Detention Facilities. Board Member Brown seconded the motion.
There was no further discussion on the motion. Vote on the motion: It passed
unanimously.
2
Excerpt from Approved Water Board Minutes January 28 2010
Staff Reports
Council's Feedback from 1218109 Work Session on the Stormwater Program Review:
Council will be asking us to look at a new purpose statement.
ORDINANCE NO. 030, 2010
OF THE COUNCIL OF THE CITY OF FORT COLLINS
AMENDING SECTION 26-492
OF THE CODE OF THE CITY OF FORT COLLINS
DECLARING THE PURPOSE OF THE STORMWATER UTILITY
WHEREAS, the declaration of purpose of the City Stormwater Utility was last updated in
1991; and
WHEREAS, in October 2008, the City Council directed City staff to review the City's
stormwater program and return to the City Council with recommendations for possible updates and
improvements to the program; and
WHEREAS, at an additional work session on December 2009,the City Council considered
staff proposals for an updated purpose statement for the stormwater program and provided feedback
to staff; and
WHEREAS, the Water Board acted in November 2008 to adopt and recommend to City
Council for adoption a proposed revised purpose statement for the stormwater program, and
considered an updated version of the proposed statement reflecting City Council's input at its
January 2010 regular meeting; and
WHEREAS, the updated stormwater program purpose statement is intended to reflect a
balanced emphasis on economic,environmental and social components in order to foster a holistic
and integrated stormwater management program consistent with the City's 21st Century Utility
Initiative.
NOW, THEREFORE, BE IT ORDAINED BY THE COUNCIL OF THE CITY OF FORT
COLLINS that Section 26-492 of the Code of the City of Fort Collins is hereby repealed in its
entirety and reenacted with the following:
Sec. 26-492. Declaration of purpose.
The City Council hereby finds, determines and declares the necessity of
providing an integrated, sustainable stormwater management program that reflects
the community's values of protecting and restoring the City's watersheds, its
tributaries and the Cache la Poudre River for mutual economic, social, and
environmental benefits including, but not limited to the following:
(1) Economic: flood damage reduction, increased recreation and tourism along
stream corridors, reduced business interruptions;
(2) Social: public safety and welfare, reduced need for emergency response,
recreation opportunities promoting community wellness; and
(3) Environmental: preserve natural and beneficial functions of floodplains,
enhance stormwater quality, preserve riparian habitat.
Introduced, considered favorably on first reading, and ordered published this 16th day of
March, A.D. 2010, and to be presented for final passage on the 6th day of April, A.D. 2010.
Mayor
ATTEST:
City Clerk
Passed and adopted on final reading on the 6th day of April, A.D. 2010.
Mayor
ATTEST:
City Clerk
ORDINANCE NO. 031, 2010
OF THE COUNCIL OF THE CITY OF FORT COLLINS
ADOPTING LANDSCAPE DESIGN STANDARDS AND GUIDELINES
FOR STORMWATER AND DETENTION FACILITIES
AS AN ADDENDUM TO THE CITY'S STORM DRAINAGE DESIGN
CRITERIA AND CONSTRUCTION STANDARDS
WHEREAS, in 1984, the City Council adopted Resolution 1984-41, approving "Storm
Drainage Design Criteria and Construction Standards" for the purpose of setting forth the
technical criteria to be used in the analysis, design and construction of storm drainage systems
within the City; and
WHEREAS, in 1991, the City Council adopted Resolution 1991-44, amending the Storm
Drainage Design Criteria and Construction Standards by the addition of"Construction Erosion
Control Criteria"; and
WHEREAS, in 1999, the City Council adopted Ordinance No.042, 1999, amending the
Storm Drainage Design Criteria and Construction Standards to substitute and replace the
Rainfall Intensity Duration Curve, and reaffirming, readopting and reenacting the Standards as
amended; and
WHEREAS, all new developments in the City are required to comply with the Storm
Drainage Design Criteria and Construction Standards, as amended, pursuant to Section 26-544 of
the City Code and Section 3.3.3 of the City's Land Use Code; and
WHEREAS, at a work session in December 2009, the City Council considered staff
recommendations for updating and improving the City's stormwater program and provided
feedback to staff; and
WHEREAS, one priority area for improvement identified in City Council discussions
was the development of landscape design standards and guidelines to establish and encourage a
more integrated approach for stormwater and detention facilities; and
WHEREAS, City staff has worked with stakeholders, the general public and the City
Water Board to develop and refine a proposed set- of "Landscape Design Standards and
Guidelines for Stormwater and Detention Facilities", attached hereto as Exhibit A and
incorporated herein by this reference (the "Landscape Standards and Facilities Guidelines"; and
WHEREAS, the Landscape Standards and Facilities Guidelines are aimed at facilitating
the infiltration of runoff, enhancing stormwater quality, increasing habitat value and plant
conservation, and increasing aesthetic appeal of detention facilities; and
WHEREAS, the Water Board voted unanimously in November 2009 to recommend
approval of the Landscape Standards and Facilities Guidelines; and
WHEREAS, the Landscape Standards and Facilities Guidelines were presented to the
Planning and Zoning Board at its February 2010 work session, and at that time members of the
Board offered positive feedback and expressions of support; and
WHEREAS, based on consideration of the anticipated economic, environmental and
social impacts of adoption of the Landscape Standards and Facilities Guidelines as part of the
Storm Drainage Design Criteria and Construction Standards, the City Council desires to adopt
the same in order to promote a holistic and integrated stormwater program consistent with the
City's 21st Century Utility Initiative.
NOW, THEREFORE, BE IT ORDAINED BY THE COUNCIL OF THE CITY OF
FORT COLLINS as follows:
Section 1. That the Storm Drainage Design Criteria and Construction Standards are
hereby amended to add as an addendum thereto the Landscape Design Standards and Guidelines
for Stormwater and Detention Facilities attached hereto as Exhibit A.
Section 2. That the Storm Drainage Design Criteria and Construction Standards as
amended are hereby reaffirmed, readopted and reenacted by the City Council.
Section 3. That the newly adopted addendum to the Storm Drainage Design Criteria
and Construction Standards as set forth herein shall not apply to any land development for which
an application for preliminary or final subdivision plan approval, or project development plan or
final plan approval has been filed with the City prior to April 6, 2010.
Introduced, considered favorably on first reading, and ordered published this 16th day of
March, A.D. 2010, and to be presented for final passage on the 6th day of April, A.D. 2010.
Mayor
ATTEST:
City Clerk
Passed and adopted on final reading on the 6th day of April, A.D. 2010.
Mayor
ATTEST:
City Clerk
EXHIBIT "A"
Forta Collins
Co '
City of Fort Collins
Landscape Design Standards and Guidelines
for
Stormwater and Detention Facilities
November 5, 2009
PREPARED BY BHA DESIGN INC .
WITH CITY OF FORT COLLINS UTILITY SERVICES
F6rta
CollinsCo '
ACKNOWLEDGEMENTS :
STEERING COMMITTEE AND CONTRIBUTORS
Rodney Albers - City of Fort Collins Utilities
Justin Morrison - Mountain - n - Plains Real Estate Services
Michael Bello - Larkspur Homes, LLC
Les Kaplan
Stu MacMillan - Everitt- MacMillan
Jim Sell - Jim Sell Design, Inc .
Jason Claeys - Jim Sell Design, Inc .
Matt Blakely - Jim Sell Design, Inc .
Jennifer Williams Almstead - VFR
Nick Haws - Northern Engineering
Herman Feissner - Feissner Consulting, LLC
Brad Anderson - Anderson Consulting Engineers, Inc .
Steve Long - Cedar Creek Associates, Inc .
Basil Hamdan - City of Fort Collins Utilities
Dana Leavitt - City of Fort Collins Planning
Steve Olt - City of Fort Collins Current Planning
Mark Sears - City of Fort Collins Nat Resources
Angela Milewski - BHA Design Inc.
Jason Messaros - BHA Design Inc .
Glen Schlueter - City of Fort Collins Utilities
Lisa Kokes - City of Fort Collins Utilities
Louise Herbert - Landscape Architect
ACKNOWLEDGEMENTS
Page 2 of 21
Stormwater Standards and Guidelines
MEN
TABLE OF CONTENTS
INTRODUCTION 1
VISION AND GOALS 1
STRUCTURE 1
VARIANCE PROCEDURES 1
BACKGROUND 2
CONCEPTS 2
INFILTRATION VS . RUNOFF 2
HABITAT VALUE 2
STORMWATER IS AN AMENITY 3
OBJECTIVES 4
DESIGN GUIDELINES 5
GENERAL CONSIDERATIONS 5
PLANNING/SITE CONTEXT 5
LANDFORM AND SLOPES 6
PLANTING DESIGN 8
PLANT SPECIES SELECTION 8
TABLE 1 : RECOMMENDED PLANT LIST 9
PLANTING TECHNIQUES 10
IRRIGATION 12
MAINTENANCE 13
APPENDICES 14
GLOSSARY OF TERMS & CONCEPTS 14
STAKEHOLDER & OPEN HOUSE COMMENTS 16
TABLE OF CONTENTS
Page 3 of 21
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CIPO: Integrated Outfall Structure CIPO - Habitat, Bio-Mimic
City of Fort Collins
Stormwater Standards and Guidelines
INTRODUCTION
The following standards and guidelines have been • Larimer County Urban Area Street Standards
developed to inform the design and maintenance of • Army Corps of Engineers
landscaping within storm drainage and detention facilities • Neighborhood Home Owner's Association
in Fort Collins . Currently the City of Fort Collins follows Requirements
written standards for the technical design of drainage and • Neighborhood Design Review Committee
detention facilities . These facilities represent a significant Requirements
portion of open space within both public and private
developments in the city. As a result, these standards VARIANCE PROCEDURES
and guidelines will improve the overall character of our These standards and guidelines illustrate and regulate
community, storm drainage function , reduce irrigation the implementation of the concepts and objectives of
demand, improve wildlife habitat, and promote the 21st Century Utilities Initiative . Their purpose is to
maintenance of these open areas . convey these fundamental concepts, but also to foster
design innovation and collaboration between city staff,
VISION AND GOALS developers, and design professionals . Proposed designs
These standards and guidelines are part of a that illustrate the spirit and accomplish the goals, but
larger vision of both the City of Fort Collins City-Wide do not conform to these standards must be approved
Sustainability Initiative and the 21st Century Utilities by the City of Fort Collins Utilities Executive Director
Initiative . This vision is : or the Director's designee . A variance request shall be
submitted in writing prior to or as part of an application
"To inspire community leadership by reducing for development review. The variance request ( s ) shall
environmental impacts while benefiting customers, the include :
economy and society" • Identifying Issue : Identification of the standard to be
waived or varied and why the standard is unfeasible .
In order to help achieve this vision, these standards and • Alternate Design : Identification of the proposed
guidelines for landscaping have been developed with the alternative design or construction criteria .
following goals : • Comparison to Standards : A thorough description
• Promote water infiltration and water quality of the variance request and how the new design
• Habitat value and plant conservation compares to the standard .
• Improve aesthetic quality • Justification : Indication of how the proposed plan
( as varied ) advances the purpose of the standard
STRUCTURE sought to be varied equally well or better than would
This document includes background information compliance with such standard .
and describes concepts and objectives for design of
stormwater facilities to meet the goals of the 21st Based upon review of the plans and additional
Century Utilities Initiative . It includes both guidelines information submitted, the Director may approve or deny
( suggested recommendations for design improvements) the variance request . If the Director of Utilities approves
and standards ( mandatory requirements for design or the variance request, the plans will continue to be
documentation ) . The standards or requirements are reviewed and approved within the typical review process .
outlined a the end of each section . If the Director denies the variance request, the applicant
This document is intended to supplement, not shall subsequently submit revised plans in compliance
supercede, current regulatory documents which may with these Standards . The Director shall provide a written
include : response outlining the basis for all approvals or denials of
• Fort Collins Land Use Code variance requests .
• Fort Collins Stormwater Design Criteria Manual
' 11 •
Page 5 of 21
F6rtclCollinsf
BACKGROUND
CONCEPTS through the soil and bedrock, recharging the groundwater
The basic concepts of stormwater management are system .
not complicated . The goal is to restore the hydrological
cycle to the extent possible and to utilize the available Runoff occurs when the soil is saturated, has become
precipitation to promote a naturalized environment impermeable or when structures and impermeable
in developed areas . This requires understanding the materials are placed on the site . Runoff tends to contain
pre-development conditions so they can be an integrated silt and pollutants that require mitigation . Excessive
system in the development . runoff also contributes to adverse hydraulic downstream
conditions causing unnatural stream bank erosion and
Site stormwater design should not simply focus on basin limited groundwater recharge .
sizing and outfall rates, but should address site drainage
as an integrated multi- use hydrologic system . This system Appropriate site design promotes natural infiltration
may include detention , water quality treatments, stream resulting in fewer downstream impacts including excessive
bank erosion control, habitat creation, infiltration, energy steam flow, exaggerated geomorphology, and reduced
dissipation, and/or recreational use . The concepts stormwater capacity of natural systems .
here illustrate specific measures which affect landscape
treatments within this overall, integrated stormwater HABITAT VALUE
design approach . Historically the area that is now Fort Collins was a
short grass prairie with a large variety of plant and animal
INFILTRATION VS . RUNOFF species . Many of these species have been displaced by the
Infiltration is a natural process by which precipitation is onset of development. Natural waterways and drainage
absorbed into the soil . Depending on the local soil type, patterns are altered by development . This decreases
some of the water remains in the top layers of soil and the functionality of existing hydrologic systems . It is
is used by vegetation . The rest of the water percolates necessary to reasonably accommodate and/or reestablish
PRE-DEVELOPMENT POST- DEVELOPMENT the hydrologic systems that existed prior to development
(TYPICAL) through the site and landscape design process .
RUNOFF INCREASED
RUNOFF '
F -
DECREASED
INFILTRATION l INFILTRATION
bone
DECREASE
RUNOFF
INCREASE INFILTRATION Naturalized Planting Improved Habitat
Value
GOAL: POST - DEVELOPMENT
DESIGNED FOR INFILTRATION
Page 6 of 21
Clity of Fort Collins
Stormwater Standards and Guidelines
STORMWATER IS AN AMENITY
Stormwater facilities have a reputation for being
functional site features without natural qualities . The basic
design parameters for a detention pond design is capacity
or volume and rate of discharge . These parameters
combined with economic factors typically result in designs
that maximize the amount of stormwater detention within
the smallest possible area .
These parameters are typically accomplished by the
creation of geometric basins with calculated volume and
outflow rates, connected to site and local utilities through
standard gray concrete and steel structures . The typical
detention basin is functional as a facility, yet, provides
little or no aesthetic or habitat benefits . In many cases
detention basins of this kind detract from the overall
project image or appeal and adversely affect surrounding
properties .
Detention ponds and waterways can instead be
designed to both meet the engineering requirements and
provide an attractive diverse space . A detention pond can
serve as a multi - use area , wildlife habitat, picturesque
scene, entry experience or educational opportunity
while maintaining the necessary functions of stormwater
detention and water quality improvement . Stormwater
facilities should be considered an opportunity for aesthetic
interest and natural integration rather than solely
necessary features of a development .
E
" Front
1 • • • A • • • l - Improved Aesthetics
BACKGROUNDErr
Page 7 of 21
F6rta
CollinsCo '
OBJECTIVES
In order to achieve the overall goals, the following and showy flowers, fall leaf color, winter texture, and
objectives must be met : grasses that persist through the winter while they
provide good wildlife habitat .
Is INFILTRATION AND WATER QUALITY • Use vegetation to frame viewsheds and enhance the
Reduce excess runoff and downstream pollution by natural aesthetic qualities of the site .
increasing on -site infiltration and water quality. Maintain
the primary functions of detention ponds and stream
drainages to attenuate flows and improve water quality
while creating and improving wildlife habitat .
• Increase pervious surface area and surface
conveyance .
• Decrease flow concentration .
• Take advantage of natural processes through
bio-filtration and bio- retention .
• Manage vegetation to insure proper drainage
functions are maintained while allowing habitat values
to be expressed to the extent possible .
2 . HABITAT VALUE AND PLANT
CONSERVATION
Create and protect habitat for a diverse array of plants
and animals; birds, mammals, insects, amphibians, and
wetland plants .
• Increase plant species diversity including the number
and variety of butterfly host plant grasses, forbs, and
shrubs as well as the number of nectar plants and
shelter plants .
• Increase the number and variety of native shrubs and
trees that provide valuable cover, berries, insects, nest
sites and other resources for migratory, nesting, and
wintering birds .
• Increase the number and variety of wetland species
that provide optimal conditions for amphibian and
reptile breeding to occur.
3 . AESTHETIC APPEAL
Create a beautiful landscape that people will enjoy
and appreciate without sacrificing function and value for
wildlife and plant habitat .
• Increase the amount of shade and resting areas along
trails and open spaces while providing habitat for
wildlife and viewing opportunities for visitors .
• Use plant species that maintain their beauty in a
variety of seasons, such as a species with colorful
Page 8 of 21
Clity of Fort Collins
Stormwater Standards and Guidelines
DESIGN GUIDELINES
GENERAL CONSIDERATIONS • Residential Development — neighborhood greenbelts,
A significant portion of a developed site often must multi - purpose recreational fields * , pedestrian trails,
be used for drainage conveyance and site detention . entry features, water features, wildlife habitat,
In planning your site, consider how the storm drainage wetland/riparian amenities, community gardens * ,
facilities can contribute to the overall character of the orchards, natural playgrounds, off- leash dog play
project . areas * .
Developers and designers should consider :
• How will the stormwater facilities be designed to
achieve the goals of this document and the needs of w
the project? j ~
r. y
• How will the stormwater facilities be designed as an
amenity rather than a necessary nuisance for this �y
project?
,y Y
PLANNING/SITE CONTEXT • Business / Retail Development — Water features, entry
Obtain and understand information about site
conditions and site context before designing the features, loop trails, picnic shelters * , visual buffer to
detention facilities, including : screen service areas from public spaces, bioswale/
landscape islands, etc .
• Adjacent and regional drainage, recreational, and
open space patterns
• On -site topography and drainage conditions
• Soil conditions
• Unique natural features, amenities or views
• Aesthetic expectations
Consider how the design of drainage facilities and
detention areas can contribute to the overall plan and
adjacent developments . Collaborate with adjacent • Industrial Development — Visual buffer to screen
property developers to formulate a more effective service and loading areas, trail connections, recreation
neighborhood or regional storm drainage plan . Look for areas, etc .
opportunities to integrate storm drainage conveyance
and water quality systems into the planned development. +�
Using bioswales, linear conveyance with check dams, and 1
inverted landscape islands throughout the project will
increase distributed infiltration and can result in reduced - or
—
land dedication requirements for larger detention ponds .
Different development types will have differing needs
that can be enhanced by thoughtful design of stormwater -*
systems that can serve multiple functions. Some concepts
to consider for detention areas based on development * Structures and fences should be designed for
types include : flooding conditions .
DESIGN GUIDEL1NEJ9mL_.
Page 9 of 21
FclrtCollinsf
o
LANDFORM AND SLOPES
f
Detention ponds engineered solely to meet the
minimum holding capacity of the required storm flows
generally result in ponds with uniform side slopes with
little natural character, or with vertical side walls that may
r
create unsafe conditions . Design pond slopes in a way that
they may also contribute to other goals . stow
know
If a detention pond is designed to also serve as a FIA
neighborhood recreation or athletic field, use gentle side MultimUse : • Passive Recreation
slopes to allow for easy access to the play fields . Steeper
side slopes can be designed with terraced flat areas to
serve as spectator seating . Other greenbelt amenities such
as picnic areas and pedestrian trails can be developed
adjacent to these spaces to create a neighborhood park
amenity that also serves as stormwater detention . While
gentler slopes for detention may require more land for the
pond, by combining the required pond area with required i
community uses, less land may be used for these open
areas overall .
Sports
MultimUse Basin * Detention & Passive Recreation, Trails /MultimUse Basine Detention Passive Recreation, Trails
THIS � NOT THIS
DESIGN GUIDELINES
Page 10 of 21
Stormwater Standards and Guidelines
Im
Detention ponds designed to be naturalized open and/or brush hogs . Consider that trash and debris must
space should include varied side slopes and an be regularly removed by maintenance personnel . Periodic
undulating bottom . Varied slope conditions will promote cleanup operations may also require the use of heavy
opportunities for plant diversity and wildlife habitat by equipment . If walls are used , they shall be limited to the
creating subtle changes in elevation above the average minimum required height and length needed . Ideally no
water level . Combine these techniques to create a wide more than 50% of a basin perimeter should be bound by
array of diverse soil conditions and exposures for plants walls . All walls shall be built of suitable materials matching
and animals to inhabit and " naturalize". adjacent architecture or designed into the landscape
scheme with natural stone or integral color concrete with
Design detention ponds with positive slopes ( 2% form liner.
minimum ) near the outlet to avoid standing water
and limit mosquito habitat . Manicured turf areas
that require regular mowing should also be sloped to Required Design Standards :
drain appropriately (4 : 1 Max) . However, flatter areas In all cases the following standards apply :
are encouraged to increase infiltration, but must be • No concrete trickle channels shall be used where
landscaped appropriately with wetland plants, forbs free draining soils are present ( Soil Group A, B ) .
and shrubs that do not require regular mowing and will Limit their use to areas with clayey soils ( Soil Group
tolerate wet and dry conditions . C, D) if necessary.
• Side slopes should vary and range from 4 : 1 to 20 : 1
Avoid the use of concrete trickle pans in areas with • No vegetated slope should exceed 3 : 1
well -draining soils as they reduce infiltration and promote • Landscaped areas should slope to drain ( 2%
evaporation and increased runoff. Where necessary, minimum ) or be planted appropriately so regular
trickle pans shall be designed as an integrated part of mowing is not required ( see PLANTING DESIGN
the landscape . Horizontal alignment shall complement section ) .
topographic character and be non linear. Embedded • Basin area cannot be 100% bound by walls . All
cobbles and/or boulders are encouraged . Color shall be a walls proposed for the pond perimeter are required
subtle earth tone . to have a high quality visual character (such as
natural stone or integral color concrete with form
General access is a primary safety consideration . liner) . Walls should not exceed 30" in height . Fences
Ramped access and gentle side slopes allow people and may be required for safety.
animals to evacuate the basin in the event of high water. • Provide a minimum of one entry point for regular
access by maintenance vehicles and mowers,
Access for maintenance equipment and personnel is and for occasional access by heavy equipment if
necessary for proper care and management of stormwater necessary. Provide adequate egress to allow users
facilities . Design slopes to provide appropriate access for to safely evacuate the area in the event of high
wheeled service vehicles, utility vehicles, lawn mowers water.
THIS Naturalized drainage channel slows drainage, NOT THIS Concrete trickle channel eliminates
promotes infiltration, allows for habitat infiltration and promotes
l „�r�� establishment evaporation and excessive runoff
a
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DESIGN GUIDELINES 7
Page 11 of 21
F6rtclCollinsf
PLANTING DESIGN PLANT SPECIES SELECTION
There is no universal approach to landscape design for Delineate planting zones with similar characteristics
detention areas . Planting design must respond to site- and proposed function . Characteristics should include
specific stormwater functions, soil types and hydrology, slope, aspect, soil type, and moisture levels . Functions may
slopes, solar aspect, availability and type of irrigation, include wildlife habitat, recreational use, or visual amenity
habitat creation , planned uses and planned maintenance . or visual screening .
A Landscape Architect can assist with a comprehensive
plan for the landscape design for your project's open space Develop a plant list for each zone type . See TABLE 1 for a
and detention areas . The following guidelines outline sample listing of appropriate plant types .
important criteria for the development of landscape plans
for these areas .
Before finalizing planting plans and seed mixes, obtain
horticultural testing of the on -site soils where planting
will occur. Testing can be completed by the Colorado
State University Soil and Crop Sciences Department for
a nominal fee . Contact the Soil -Water- Plant Testing Lab
at http ://www. extsoilcrop . colostate . edu/SoiILab/soiIlab .
html for more information . Often planting plans must
be completed before construction activities take place,
so final soil conditions for areas to be planted are not
available at the time of design . If overlot grading is planned
to occur after the planting plans are complete, require
the contractor to incorporate 6" of topsoil from on -site or
imported source into final grading operations, and indicate
that the final seed mixes will be modified after final
grading is complete and subsequent horticultural tests are
evaluated .
Use native and adapted plants . Proper landscape design
with native plants based on a site's unique conditions can :
• Reduce or eliminate need for supplemental irrigation
• Reduce fertilizer and chemical pest control needs
• Enhance wildlife habitat
• Reduce maintenance needs
Plants should be screened for invasiveness by using
the Nature Conservancy's Nature Serve Explorer website
at http ://www. natureserve . org/explorer/servlet/
NatureServe ? init=Species
Page 12 of 21
Clity of Fort Collins
Stormwater Standards and Guidelines
MEN
TABLE 1 : RECOMMENDED PLANT LIST
TREES AND SHRUBS GRASSES
Upland Species — North and East Facing Species for Upland Slopes
Fourwing Saltbush (Atriplex canescens) Little Bluestem ( Schizachyrium scoparium )
Rubber Rabbitbrush (Chrysothamnus nauseosus) Side Oats Grama ( Bouteloua curtipendula )
Three- leaf Sumac (Rhus trilobata) Blue Grama ( Bouteloua gracilis )
Native Smooth Sumac (Rhus glabra) Western Wheatgrass ( Pascopyrum smithii )
Wood's Rose (Rosa woodsii) Green Needlegrass ( Nassella viridula )
White Snowberry (Symphoricarpos alba) Slender Wheatgrass ( Elymus trachycaulus )
Western Snowberry (Symphoricarpos occidentalis) Buffalograss ( Buchloe dactyloides )
Netleaf Hackberry (Celtis reticulate) Bottlebrush Squirreltail ( Elymus elymoides )
Sand Dropseed ( Sporobolus cryptandrus )
Upland Species — South and West Facing Alkali Bluegrass ( Poa juncifolia )
Fourwing Saltbush (Atriplex canescens) Sun Sedge ( Carex inops ssp . heliophila )
Rubber Rabbitbrush (Chrysothamnus nauseosus)
Three- leaf Sumac (Rhus trilobata) Species for Subirrigated Areas
Desert False Indigo (Amorpha canescens) Big Bluestem (Andropogon gerardii)
Winterfat (Krascheninnikovia lanata) Switchgrass (Panicum virgatum)
Yucca (Yucca glauca) Yellow Indiangrass (Sorghastrum nutans)
Alkali Sacaton (Sporobolus airoides)
Species for Moist, Well-drained Areas Green Needlegrass (Nassella viridula)
(2. 5-6 feet above high water line or one-year storm ) Western Wheatgrass (Pascopyrum smithii)
Saskatoon Serviceberry (Amelanchier alnifolia) Nuttall Alkaligrass (Puccinellia airoides)
Shiny- leaved Hawthorn (Crataegus erythropoda) Canada Wildrye (Elymus canadensis)
Wild Plum (Prunus Americana)
Western Chokecherry (Padus virginiana var. Species for Wetland Areas
melanocarpa) Prairie Cordgrass (Spartina pectinate)
Western Sand Cherry (Prunus bessyi) Canada Wildrye (Elymus canadensis)
Cottonwood Tree (Populus spp. ) Switchgrass (Panicum virgatum)
Netleaf Hackberry (Celtis reticulate) Inland Saltgrass (Distichlis spicata)
Fowl Bluegrass (Poo palustris)
Species for Subirrigated Areas Nebraska Sedge (Carex nebrascensis)
( 1-3 feet above high water line) Woolly Sedge (Carex lanuginose)
Leadplant (Amorpha fruticosa) Creeping Spikerush (Eleocharis palustris)
Redosier Dogwood (Cornus sericea) Torrey's Rush (Juncus torreyi)
Golden Currant (Ribes aureum) Baltic Rush (Juncus balticus)
American Black Currant (Ribes americanum)
Peachleaf Willow (Salix amygdaloides)
JAL_ Aim
DESIGN GUIDELINES 9
Page 13 of 21
F6rtclCollinsf
PLANTING TECHNIQUES Drill seed specified mix in two passes, each at right
angles to each other. Drill half of the seed in each pass . If
Soil Preparation areas are too wet or steep to drill seed, broadcast seed in
Good soil is the foundation of a successful landscape . two opposite directions . Restore fine grade after seeding,
Planting areas require topsoil with appropriate levels of and cover seed to depth of 1/4 inch by raking or dragging.
organic matter. Spread imported or stockpiled topsoil to Firm seeded areas with a roller weighing maximum of 100
a minimum depth of four inches over areas to be planted . lbs . per foot of width .
For native seed areas, additional soil amendments are
not necessary. Native plants are adapted to the native Use of erosion control blankets may be needed on
soils, and the additional organic matter found in soil steeper slopes (greater than 6 : 1 ), or non - irrigated south -
amendments may instead promote weed growth . facing and west-facing slopes to reduce erosion, improve
soil moisture and seed germination . Natural fiber blankets
Sub-grade in planting areas should be loosened to a are preferred to synthetic blankets which can entangle
minimum depth of twelve ( 12 ) inches overall ( 8" of existing reptiles and amphibians in pond settings . Install erosion
sub-grade and 4" of new topsoil ) . Remove stones and control blankets as per manufacturer's recommendations .
clods that could impede planting, seeding, and mowing .
Stones protruding from the soil more than 3" should be Remaining seeded areas should be mulched to reduce
removed . Collect and legally dispose of sticks, roots, seed loss and improve soil moisture and germination .
rubbish, and other extraneous matter. Repeat cultivation Large sites without irrigation can be mulched with straw
in areas where equipment used for hauling and spreading mulch . Straw mulch should be certified weed -free hay or
topsoil has compacted the soil . Fine grade disturbed certified weed-free straw with no seed heads, crimped into
planting areas to a smooth , uniform surface plane with the seed bed after seeding has occurred . Irrigated sites can
a loose, uniformly fine texture . Grade to within the be hydromulched after seeding has occurred .
acceptable tolerances provided by the certifying civil
engineer. Roll and rake, remove ridges, and fill depressions Wetland Plantings and Subirrigated Plugs
to meet finish grades based on grading plans . Concentrate wetland plantings in areas where erosion
is anticipated or where favorable moisture zones are
Weeds thrive in soil disturbed by grading operations . likely to exist . Since planned moisture levels are difficult
Use of appropriate herbicides prior to planting can help to to predict, plant species in, above, and below their ideal
reduce the onset of noxious weeds and other aggressive zone to accommodate for both high water and low water
non-desirable plants . Apply non-selective herbicides seasons . Plants are then likely to establish in their optimal
to weeds after fine grading has occurred and prior to conditions . Since detention areas fluctuate with storm
planting. Herbicide shall be ' Round - Up' or similar product conditions, use species with wider tolerances to moisture
that will not persist in the soil and negatively affect conditions .
planting operations .
Wetland plugs may be necessary in areas that cannot
Seed Mixes and Installation Techniques be seeded due to constant inundation or saturation .
Seed mixes should be developed based on the on-site Plant plugs after drill seeding from mid - May through
soil conditions determined with the soil horticultural tests . July. Planting small plugs in the fall is less desirable due
Since detention and drainage areas have varying moisture to loss of plants to Canada Geese . Plug plantings can
conditions and slopes, develop a diverse seed mix with a be completed immediately after seeding. Subsequent
wide ecological amplitude . When multiple seed species are plug plantings are recommended after initial seed
used, they will tolerate a wide array of soil and moisture establishment when weeds are under control ( 2 -5 seasons
conditions . See TABLE 1 for a list of appropriate grass types after initial construction ) . These later plantings can be
for various planting zones . concentrated in bare areas and those areas needing
erosion control protection .
Page 14 of 21
Stormwater Standards and Guidelines
Wetland plugs may be planted 12" to 24" on center a natural habitat and reduce the cost of structured
and may need protection with turf reinforcement mats, protection measures . Seeding schedule should be per
jute or similar erosion control devices . Plugs can be seed source recommendation . Trees and shrubs should be
caged or covered with wire fabric, jute or other products planted prior to seeding .
for protection if damage by geese or small mammals is
anticipated . In areas of standing water, grids of string � ;
slightly above the water elevation can also be installed to Required Design Standards :
reduce waterfowl access to newly planted areas . In all cases the following standards apply :
•Trees and Shrubs Enlist the services of a Landscape Architect to
prepare the required landscape construction plans
Concentrate or group shrubs and woody plants into for commercial project detention areas .
beds or groups to more quickly create habitat for wildlife • Develop plant lists and seed mixes based on
and to reduce weeding, watering and maintenance horticultural testing of site soil conditions .
requirements . Select species based on the optimal • Delineate planting zones based on soil
moisture zones . Construct planting wells around each tree characteristics and function . Develop plant lists
or group of woody plants to capture natural moisture for appropriate for each planting zone .
the plants . Use organic mulch in planting beds or in tree • Use native and adapted plants .
wells to increase moisture retention and to reduce weed • provide a minimum of one entry point for regular
and grass encroachment . Avoid using weed barrier around access by maintenance vehicles and mowers,
trees an shrubs . and for occasional access by heavy equipment
if necessary. Do not block access with designed
Use shrubs and wetland plants strategically near inlets landscape features .
to soften the visual impact of these man- made structures • Stockpile and redistribute ( or import if necessary) a
without impeding storm drainage function . Avoid the use minimum of four inches of topsoil over areas to be
of exposed rip- rap . Rip- rap if used shall be a subtle earth planted .
tone color, not pink, and should be buried and integrated • Use non - persistent herbicide prior to planting to
with erosion control matting, and planting to soften
curtail weed establishment .
the visual impact and provide opportunities for habitat • Incorporate erosion control blankets and/or
establishment . Other types of less intrusive erosion appropriate mulch to reduce erosion and improve
control materials which incorporate planting materials soil moisture conditions for new plantings .
should be considered . Bio-engineered solutions are • Use wetland species in appropriate areas and pond
preferred in lieu of structural erosion control measures . bottoms likely to be too wet for regular mowing
Brush layering and use of live branch cuttings can restore and maintenance .
and protect stream banks and outFall areas while creating
THIS NOT THIS
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Exposed pipe, `y
Naturalized rip-rap or cobble [ � ^�� no landscape context, • �� � '� '
stones partially buried, broken �1"ii� �� 1 ' exposed rip-rap of uniform color and
edges, streambed appearance size, straight edges and square corners
DESIGN GUIDELINES I I
Page 15 of 21
F6rta
CollinsCo '
IRRIGATION
Since storm drainage and detention areas account
for the most significant portions of open landscaped
space in most projects, their design can greatly impact
the amount of irrigation water demand for a project .
Irrigation and landscape design should correspond to
the types of uses planned for the detention areas . Areas
planned for high pedestrian use such as recreational fields
will require higher irrigation needs to provide regular,
controlled irrigation levels . More natural areas may be
able to minimize or eliminate completely the need for
supplemental irrigation . Landscape designs are encouraged
to respond to each site's unique soil conditions and
planned hydrology to minimize or eliminate the need for
supplemental irrigation .
DESIGN GUIDELINES
Page 16 of 21
MAINTENANCE
Required Design Standards :
Weed Control In all cases the following standards apply :
The primary method of weed control during the initial � Use regular mowing as a primary weed control
establishment period (two to three growing seasons ) for method during initial establishment period .
seeded areas is regular mowing . Regular mowing helps e Limit use of chemical herbicides, and only use those
prevent weed seeds from being produced . Careful spot appropriate for conditions . Use non persistent
spraying is also acceptable, but many herbicides affect herbicides in upland areas, and aquatic approved
seedling grasses and non-target plants . Always read and herbicides near wet, wetland or water areas .
follow label directions . After the initial establishment • Suppress cattails for the first three to five growing
period , if chemical weed controls are needed in the seasons to allow less aggressive native species to
pond bottoms of wet detention areas, herbicides should establish .
be selected that have an aquatic label . Even herbicides Monitor and correct areas of erosion .
approved for aquatic use should only be used during • Limit irrigation and fertilization to that needed for
periods of dry weather and dryer conditions to reduce the plant establishment and specific designed needs .
amount of herbicide that gets into the water itself. Side Naturalized areas with native plants are adapted
slopes generally above the high water line can be sprayed to Colorado soils so should only require irrigation
with non -aquatic but non - persistent herbicides as per the during the initial establishment period , and
manufacturer's recommendations . should not require fertilization . High - use or active
recreation areas will require more regular irrigation
Cattails will generally establish in created detention and standard fertilization practices .
areas through natural dispersal . Although they are a
native species, they are often so competitive that they
become a mono-culture if not managed . Cattails should be
suppressed for the first three to five growing seasons to
allow less aggressive native species to establish .
Erosion Control
Areas of erosion should be monitored and corrected
to prevent damage to the landscape and storm drainage
structures .
Irrigation and Fertilization
Supplemental irrigation will be needed during the
initial establishment period . However, once established,
naturalized drainage and detention areas using native
plants and species appropriate for the specific moisture
regimes should not require fertilizers or supplemental
irrigation after establishment . Irrigation used during
establishment can either be reduced or eliminated
altogether. Limit the use of fertilizers in native plant areas .
In detention basins that also serve as recreation fields
or active neighborhood spaces, permanent irrigation and
more standard fertilization , aeration , and weed control
practices are appropriate to keep a more manicured
appearance .
Page 17 of 21
F6rtclCollinsf
APPENDICES
GLOSSARY OF TERMS & CONCEPTS
Base Flow — The portion of stream flow that is not runoff and Green Roof - A contained space over a building that is covered,
results from seepage of water from the ground into a channel partially or entirely, with living plants .
over time . The primary source of running water in a stream
during dry weather. Groundwater - Water that flows below the ground surface
through saturated soil, glacial deposits, or rock.
Best Management Practice ( BMP), nonstructural— Strategies
implemented to control stormwater runoff that focus on Hydrologic Soil Groups - Soil groups based on estimates of runoff
pollution prevention, such as alternative site design, education, potential . Soils are assigned to one of four groups according to
and good housekeeping measures . the rate of water infiltration when the soils are not protected by
vegetation, are thoroughly wet, and receive precipitation from
Best Management Practice ( BMP), structural — Engineered long-duration storms.
devices implemented to control, treat, or prevent stormwater Group A . Soils having a high infiltration rate ( low runoff
runoff. potential ) when thoroughly wet . These consist mainly of
deep, well drained to excessively drained sands or gravelly
Bio-filtration — The use of vegetation such as grasses and sands . These soils have a high rate of water transmission .
wetland plants to filter and treat stormwater runoff as it is Group B . Soils having a moderate infiltration rate when
conveyed through an open channel or swale, or collects in an thoroughly wet . These consist chiefly of moderately deep
infiltration basin (see Bio- retention ) . or deep, moderately well drained or well drained soils that
have moderately fine texture to moderately coarse texture .
Biological Diversity — The concept of multiple species or These soils have a moderate rate of water transmission .
organisms living together in balance with their environment and Group C. Soils having a slow infiltration rate when
each other. thoroughly wet . These consist chiefly of soils having a layer
that impedes the downward movement of water or soils of
Bio-retention — The use of vegetation in retention areas moderately fine texture or fine texture . These soils have a
designed to allow infiltration of runoff into the ground . The slow rate of water transmission .
plants provide additional pollutant removal and filtering Group D. Soils having a very slow infiltration rate ( high
functions . runoff potential ) when thoroughly wet. These consist chiefly
of clays that have a high shrink-swell potential , soils that
Detention - The storage and slow release of stormwater have a high water table, soils that have a claypan or clay
following a precipitation event by means of an excavated layer at or near the surface, and soils that are shallow over
pond, enclosed depression, or tank. Detention is used for nearly impervious material . These soils have a very slow rate
both pollutant removal, stormwater storage, and peak flow of water transmission .
reduction . Both wet and dry detention methods can be applied . If a soil is assigned to a dual hydrologic group (A/D, B/D,
or C/D ), the first letter is for drained areas and the second
Evapotranspiration - The loss of water to the atmosphere is for undrained areas . Only the soils that in their natural
through the combined processes of evaporation and condition are in group D are assigned to dual classes .
transpiration, the process by which plants release water they
have absorbed into the atmosphere . Hydrology - The science addressing the properties, distribution,
and circulation of water across the landscape, through the
Filter Strip - Grassed strips situated along roads or parking ground, and in the atmosphere .
areas that remove pollutants from runoff as it passes through,
allowing some infiltration, and reductions of velocity. Impervious surface - A surface that cannot be penetrated by
water such as pavement, rock, or a rooftop and thereby prevents
Floodplain - Can be either a natural feature or statistically infiltration and generates runoff.
derived area adjacent to a stream or river where water from the
stream or river overflows its banks at some frequency during Imperviousness - The percentage of impervious cover within a
extreme storm events . defined area .
Page 18 of 21
Stormwater Standards and Guidelines
Infiltration - The process or rate at which water percolates from gravitational settling to remove soil or rock particles from the
the land surface into the ground . Infiltration is also a general water column .
category of BMP designed to collect runoff and allow it to flow
through the ground for treatment . Siltation - A solid -liquid separation process utilizing gravitational
settling to remove fine-grained soil or rock particles from the
Metered Detention and Discharge - A system where stormwater water column .
is collected in a cistern pond and then slowly released into the
landscape beds or the storm drain in the following hours at Storm sewer system - A system of pipes and channels that carry
the rate that allows for better filtration and is less taxing to the stormwater runoff from the surfaces of building, paved surfaces,
overall community storm drain . and the land to discharge areas .
National Pollutant Discharge Elimination System ( NPDES) - A Stormwater - Water derived from a storm event or conveyed
provision of the Clean Water Act that prohibits discharge of through a storm sewer system .
pollutants into waters of the United States unless a special
permit is issued by the EPA, a state, or (where delegated ) a tribal Surface water - Water that flows across the land surface, in
government or and Indian reservation . channels, or is contained in depressions on the land surface (e .g.
Runoff , Ponds, Lakes, Rivers, and Streams) .
Outfall - The point of discharge from a river, pipe, drain, etc. to a
receiving body of water. Swale - A natural or human- made open depression or wide,
shallow ditch that intermittently contains or conveys runoff.
Peak discharge - The greatest volume of stream flow occurring Swales can be equipped with an underdrain or other man- made
during a storm event. drainage device . and can be used as a BMP to detain and filter
runoff .
Pervious - Admitting of passage or entrance . Material that
permits elements such as water and oxygen to enter and or pass Urban runoff - Runoff derived from urban or suburban land-
through . uses that is distinguished from agricultural or industrial runoff
sources.
Polluted runoff - Rainwater or snow melt that picks up pollutants
and sediments as it runs off roads, highways, parking lots, lawns, Water ( hydrologic) cycle - The flow and distribution of water
agricultural lands, logging areas, mining sites, septic systems, and from the sky, to the Earth's surface, through various routes on or
other land- use activities that can generate pollutants . in the Earth, and back to the atmosphere. The main components
are precipitation, infiltration, surface runoff, evapotranspiration,
Porous pavement and pavers - Alternatives to conventional channel and depression storage, and groundwater.
asphalt that utilize a variety of porous media, often supported
by a structural matrix, concrete grid, or modular pavement, Water table — The level underground below which the ground is
which allow water to percolate though to a sub- base for gradual wholly saturated with water.
infiltration .
Watershed - The land area, or catchment, that contributes water
Retrofit - The creation or modification of a stormwater to a specific water body. All the rain or snow that falls within
management practice, usually in a developed area, that this area flows to the water bodies as surface runoff, in tributary
improves or combines treatment with existing stormwater streams, or as groundwater.
infrastructure .
Runoff - Water from rainfall, snow melt, or otherwise discharged
that flows across the ground surface instead of infiltrating the
ground .
Sanitary sewer system - Underground pipes that carry only
domestic or industrial wastewater to a sewage treatment plant
or receiving water.
Sedimentation - A solid- liquid separation process utilizing
Page 19 of 21
F6rta
CollinsCo '
STAKEHOLDER & OPEN HOUSE COMMENTS
• A landscape plan for all stormwater facilities must natural state and not manicured .
be prepared by a professionally licensed Landscape • Encourage bioswales, etc . in and around site .
Architect with experience in stormwater facility • Incentive to allow water to be treated at source in rain
design . gardens / bioswales / etc .
• List possible techniques/solutions with examples • Provide support that will lead to decrease in required
and case studies to help appease those entering into pond volumes such as narrower streets, pervious
uncharted territory ( both applicants and reviewers ) . . . pavements, etc . Currently engineering will not allow
this will help avoid the " pioneers get the arrows, and pervious pavement or bioswales
the settlers get the land" dilemma . • No pan requirements in ponds
• Along with various options, include the design • Don 't just default to Urban Drainage; allow variation
criteria to which City Staff will review against. If suitable to project type and size . Allow credit for
every applicant and design team needs to justify the developments that try several LID practices even if it
proposed solutions on their own, and spend extra can't be modeled or formulated in U . D. Let 's see if it
time and money getting Staff on board, it will serve works provided downstream not affected .
as a deterrent to implementing some of these new • How can we quantify infiltration / to allow for smaller
techniques . Obviously, the guidelines cannot account ponds?
for every potential option , and they need to remain • What plants can work in flat- bottom swales ( no
fluid to allow future solutions and innovations not yet concrete pan )
known . However, to get the ball rolling and encourage • City inspectors requiring concrete pans !
more imminent alternatives, not asking each project • Keep in mind expansive clay soils, cannot hold / direct
to 'fight the battle' so-to-speak would be a great water across them without issues .
benefit . • Different standards ( maintenance / design /aesthetics )
• Please put these boards on the website . for different uses / districts = industrial vs . retail
• More Wet Ponds, or flat bottom, because it provides • Civil Engineers tend to "engineer" a solution in the
additional volume least amount of space
• n Desi
• How do you handle clay soils ? Integrated g
• Use appropriate landscaping materials • Go from utilitarian to "aesthetic"
• If using sub drain , provide outlet • Multi use spaces included in final design
• Ponds should have concrete weir — because it provides • Need more cooperation between city departments to
a reference elevation reduce maintenance requirements ( onerous) on HOA's
• Slow H2O down to increase infiltration . • Go for the more natural look.
• Remove concrete pans to assist / allow areas to be • Materials :
more natural . Use planting in this area to build upon A . No rock?
drainage path . B . No concrete ?
• Reevaluate stormwater requirements to over store C . No vertical edges ?
H2O. D . No irrigation ? — ( native and adaptive )
• Take into account H2O uptake of plant material . • Green ( grass ) vs . Green ( money) vs . Green
• Use of injection / percolation wells to speed ( sustainable )
absorption . • Flexible aesthetics per property / project
• Combine system with pervious pavement solutions to • Distributed smaller detention
maximize usable land .
• No regional pond .
• Provide incentives for innovation .
• Savings from less storm sewer.
• How can green roofs help with the reduction / delay of • Raised landscape islands converted to depressed
stormwater discharge ? landscape islands
• Incentive to developer to allow pond areas to be in • Incentives for :
Page 20 of 21
Clity of Fort Collins
Stormwater Standards and Guidelines
A . Dispersed system • Standards vs . Guidelines
B . Water quality • Prescriptive vs . Proscriptive
• Slow down the water ! • Requirement for Landscape Architect on design team
• Regional / Neighborhood detention facilities vs . each • Combination ? If walls then upgrade
site — with fee similar to street over sizing • Engineering staff on team
A . Regional ( City) • LUCASS staff on team
B . Neighborhood • Life cycle vs . Front end cost
C . Private • Continue to promote growth and development
• Infill projects • Multiple use = multiple approaches
A . Smaller facilities • Difficult with little used areas
B . Swales with infiltration • No fertilizer unless play fields
• Linear detention keep larger ponds sizes down • No irrigation ( except during establishment)
• Inverted landscape islands in parking lots • Required ground cover
• Alternatives for wetland mitigation similar to Corp of • Context for plant types
Engineers in lieu of fee ? A . Categories for use, wetland , soil type, landscape,
• May not apply to detention ponds maintenance
• LID — encourage small ponds close to source B . Review Urban Drainage Standards
• Concentration of surface area C . New development vs . Infill / redevelopment
A . Less curb and gutter
B . More infiltration
C . * Increased surface area
D . Greenbelts conveying and slowing water
( check dams) to increase infiltration
• Native soils = little infiltration but slowing rate through
bioswales still help with down stream flows
• Tucson = standards top in nation as model
• City needs to be able to accept new ideas
A . Rocky mountain innovation
B . Infiltration ? City requires 2X capacity if case it
doesn't work
C . Include innovation process in standards
• Collaboration — encourage collaboration among project
team members and between team and city
• City to take a leadership role in new techniques
• Help developer to understand benefits . * Examples of
successful projects ?
• Example projects schematics, concepts illustrated
• Eliminate risk by having guidelines on the books
• Access for maintenance
• Mowing ( private Maintenance )
• Backhoes / Dumptrucks for sediment removal ( city)
• Partnership between private and city
• Gently sloping sod, few trees
• No walls?
• Limit walls to allow maintenance
• Underground detention ?
• How do you deal with long term maintenance ?
JAKEHOLDER & OPEN HOUSECOMMENTS
Page 21 of 21