ALBUQUERQUE’S MOVE
TOWARDS A LOW IMPACT
DEVELOPMENT FUTURE
Presentation to the 2011 MS4 Region 6 Conference
By Roland Penttila, P.E.
Stormwater Section Manager, Engineering Division
Stormwater Management Section
Organization Chart
Roland Penttila
Section Manager
Capital
Improvement
Projects
[3 people]
Engineering
Support; CAD
[1 person]
Stormwater
Quality – MS4
compliance
[1 person]
Total of one person for SWQ & MS4
Background
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Albuquerque is a 188.6 square mile city of 530,000
population within a metropolitan area of 900,000
Albuquerque was founded in 1706 and celebrated its
tri-centennial five years ago
It is the largest city in New Mexico and the only one
with a population over 100,000
We are located in north central New Mexico on the
Rio Grande
Presentation to 2011 Region 6 MS4
Conference
Location Map
Background
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The climate is mild with an average of 300 days
of sunshine a year with temperatures between
200 & 950F
The area receives approximately 9 inches of rain
per year which classifies it as “arid”
About half of annual rainfall usually occurs in
the three months of July, August and
September.
Flooding has been caused by highly localized
storms with rainfall intensities of 2 to 3
inches/hour for short periods of time.
Presentation to 2011 Region 6 MS4
Conference
Albuquerque Precipitation
compared to other Region 6 cities
30 year mean average from 1971 to 2000 from NOAA
60
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El Paso
ABQ
San Antonio
Oklahoma City
Dallas
Houston
Little Rock
New Orleans
= 8.8
= 9.0
= 33.0
= 33.4
= 33.7
= 46.0
= 50.9
= 59.8
El Paso
ABQ
50
40
San
Antonio
30
Oklahoma
City
Dallas
20
Houston
10
Little Rock
0
Inches/year
New
Orleans
MS4 History
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New Mexico does not have primacy (only state in
EPA Region 6 that does not)
Applied for first Phase I permit in 1999
Received first Phase I permit in 2003
First permit expired in 2008 but was administratively
extended by Region 6
Region 6 working on a renewed permit since 2008
We were the last City in the U.S. to get an MS4
Phase 1 permit
Presentation to 2011 MS4 Region 6 Conference
MS4 History
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First permit (2003 – 2008) was like a learner’s permit
We were struggling to find our way
Very few funds were allocated for permit-related
activities…less than $200,000 per year
Most funds went for required sampling and testing
Only one staff member was (is) devoted to all permit
compliance activities
First permit had a lot of “will investigates,” “will
research,” “will attempt” and no deadlines
Our pending 2nd permit has lots of “shalls” and specific
compliance deadlines
Presentation to 2011 MS4 Region 6 Conference
MS4 Future
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The six minimum measures were not in the first permit
as those were to be associated with Phase 2 cities. They
will be in the next permit
One of the six is Post-Construction Stormwater Management,
or Low Impact Development
The pending permit requires that we “update or enact
an ordinance to ensure implementation” of LID
General guideline is to “mimic pre-development hydrology”
The difficulty is to create and place engineering
boundaries around that general guideline
Presentation to 2011 MS4 Region 6 Conference
LID definition
“LID is an approach to land development (or
re-development) that works with nature to
manage stormwater as close to its source as
possible. LID employs principles such as
preserving and recreating natural landscape
features, and minimizing effective
imperviousness to create functional and
appealing site drainage that treats stormwater
as a resource rather than a waste product.”
Low Impact Development (LID)
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Many implementation strategies
Will have to be defined differently in Albuquerque than
most every other place
“All calculations based on experience
elsewhere, fail in New Mexico”
Lew Wallace, Territorial Governor of New Mexico
from 1878 to 1881 (and author of Ben Hur)
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So, how to define LID for Albuquerque? Remember
that 50% of our total annual rainfall happens in just
three months of the summer
What our draft MS4 permit requires…
„ Assess impediments to green
infrastructure and develop a report
„ Set design standards that prevent an
increase in the 100-year, two-hour peak
runoff, a change in the time of the peak,
or increase in total runoff from predevelopment conditions
„ “mimic pre-development hydrology”
Albuquerque’s Storm Drainage
Ordinance
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Created in 1981
Originally created to limit developed runoff to
“downstream capacity” to reduce the potential
for flooding
Work of a very large committee of developers,
planners, engineers including AMAFCA
Approved by City Council as an ordinance
Called for a document which would lay out
design criteria and review procedures
Albuquerque’s DPM
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The DPM stands for the Development Process
Manual and came out of the Ordinance in 1981
The DPM sets forth all the design criteria and
project approval procedures for private and
public development
Only a few changes in the past 20 years
Any changes are reviewed and approved by a
DPM Technical Committee including members
from the engineering & development
community
Changes to the Ordinance
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The DPM committee began meeting on March
1st of this year led by Chuck Easterling, P.E.
who was also instrumental in the creation of the
original document 30 years ago
There were about eight long meetings at which
every word and sentence of the 1981 Ordinance
were evaluated for LID applicability
The work was concluded on June 24th with a
draft “LID” version of the Ordinance
Changes to the Ordinance
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While working on the LID changes, the
committee also worked on new construction
inspection procedures for development projects
That effort was led by Terry Baus, P.E. of
CH2MHill
This will strengthen the
city’s inspection
authority over
construction projects
The Approach
In analyzing
precipitation statistics
from 1891 to 2010, the
rainfall volume vs.
probability curve
showed the 90th
percentile storm was
0.44 inches.
0.44” was the volume
chosen as the LID
volume for first-flush
capture
90th percentile storm
3.5
Daily Rainfall Depth (in)
3.0
Note that the lowest rainfall of all these
gages is at the Sunport – the official
weather station of the city.
2.5
2.0
1.5
1.0
0.5
0.0
0%
50%
100%
Tijeras
Sunport
Taylor
Academy
Arr19a
Bear
Borland
Camino
Campus
Fs14
Hahn
Laboca
Lacueva
Fs16
Ladera
Cumulative Frequency of Daily Rainfall Depths (%)
15 USGS rain gage stations from 1970 to 2010
What’s Changed
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Added Stormwater Quality and LID definitions to what
had only been a FLOOD ordinance
Added stormwater quality and compliance with the
Clean Water Act as a goal of the ordinance
Added new inspection responsibilities to contractors
and city inspectors working on active development
projects to control erosion and sediment
Added Post Construction Maintenance requirements
What’s Changed
New Section
“The City Engineer shall not approve any plan
pertaining to construction, platting or other
development…for which stormwater quality
control has not been addressed”
But Wait!
Albuquerque is already an “LID” city
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Most of the city was developed during the 50s and
60s and the standard lot was built with concrete
block walls surrounding the entire back yard.
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In addition, the majority of the roof structures were
flat and slanted to drain to those back yards.
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58% of the residential land rarely contributes to
stormwater runoff.
Albuquerque’s Zoning by Segment
Industry-Manufacturing is only 8% of land use
8%
8%
2% 1%
9%
11%
Residential
Recreation
Comm & Office
61%
Transportation
Industry-Mfg
Not classified
Residential is 61% of land use
Presentation to 2011 Region 6 MS4
Conference
Government
In early 2010, K.T. LaBadie, working
on her Master’s Degree at UNM,
brought together a focus group of
developers, private and government
engineers, community leaders and
educators to discuss LID and
identify local barriers to
implementation.
That effort defined some possible
arid-acceptable approaches that
could be used to begin rolling out
LID in this area.
This study is available at:
www.aridlid.org
Presentation to 2011 MS4 Region 6 Conference
Favored arid LID features
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Harvesting parking lot runoff or “green parking”
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More extensive use of rain barrels
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Harvesting street runoff or “green streets”
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Green detention facilities such as small scale basins
to collect first flush flows
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Increased urban tree cover
Presentation to 2011 MS4 Region 6 Conference
Unfavored arid LID features
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Swales or other earthen structures
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Flow-through planter boxes
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Rain gardens (where’s the “rain?”)
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Green Roofs
Presentation to 2011 MS4 Region 6 Conference
So, what’s next?
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Legal review of Ordinance Changes
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Public informational meetings with engineering and
development community
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Adoption by City Council
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Mayoral approval
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Begin drafting the technical and engineering changes to
the DPM
Presentation to 2011 MS4 Region 6 Conference
Schedule
Council and Mayor Approval
Nov 2011
DPM Changes
May 2012
Begin implementing changes
July 2012
Presentation to 2011 MS4 Region 6 Conference