This document summarizes a reservoir planning study being presented to the Evanston City Council. It provides background on previous structural evaluations that found the 1913, 1934, and 1948 water storage facilities to be in poor condition. The current study aims to comprehensively evaluate Evanston's water storage and treatment needs over the long term to determine the most cost-effective solution. It will analyze repairing the existing structures versus replacing them and consider six alternatives, including replacing or repairing reservoirs at different locations.
Topics:
1. Reservoir Classification
2. Investigations
3. Selection of Site for Reservoir
4. Zones of Storage
5. Storage Capacity and Yield
6. Mass Inflow Curve & Demand Curve
7. Calculation of Reservoir Capacity
8. Reservoir Sedimentations
9. Life of Reservoir
10. Selection of Dam
Reservoir Planning: Introduction; Investigations for reservoir planning; Selection of site for a reservoir; Zones of storage in a reservoir; Storage capacity and yield; Mass inflow curve and demand curve; Calculation of reservoir capacity for a specified yield from the mass inflow curve; Determination of safe yield from a reservoir of a given capacity; Sediment flow in streams; Life of reservoir; Reservoir sediment control; flood routing. Various types of Spillways and design.
Introduction, Term related to reservoir planning (Yield, Reservoir planning and operation curves, Reservoir storage, Reservoir clearance), Investigation for reservoir planning, Significance of mass curve and demand curves, Applications of mass-curve and demand curves, Fixation of reservoir capacity from annual inflow and outflow, Fixation of reservoir capacity.
A hydraulic structure may be defined as any structure which is designed to handle water in any way
This includes the retention, conveyance, control, regulation and dissipation of the energy of water
Such water handling structures are required in many fields of civil engineering
The principal ones being water supply and conservation, hydroelectric power, irrigation and drainage, navigation, flood control, fish, wildlife service’s and certain aspects of highway engineering. Various equations, based on continuity, energy, and momentum principles, may be used
To calculate the most suitable length, width, shape, elevation and orientation of the structure.
The application of these basic principles to the practical problem of the design of hydraulic structures is called hydraulic design
Designed and constructed for managing and utilizing water resources to the best advantage of the human being and environment
Seepage through canals_seminar presentationRaj Bisen
This Presentation represents Final year seminar presentation on seepage through lined and unlined canal by swamee et al method. submitted to HoD, Government College of Enginneering, Amravati By Raj Bisen.
Canal & canal types with design of channels by dj sir covered kennedy lacey t...Denish Jangid
Canal its types with design of channels by Denish Jangid sir.
covered kennedy lacey theory IS code method with comparison drawbacks.
design steps by kennedy
design steps by lacey
design of canal types of canal trapezoidal shape. Canal Irrigation. Subject-
Water Resources Engineering By Dr.* Denish Jangid Assistant Professor Civil Engineering Department
Canal Classification based on Financial returns
Canal Classification based on Use
Canal Classification based on Size
Cana Masonry work
alluvial soil
Cross regulator
Head regulator
Silt Control device
Silt ejector
Silt excluder
Factor affecting the Canal Alignment
A contour canal is an artificially-dug navigable canal which closely follows the contour line of the land it traverses in order to avoid costly engineering works such as boring a tunnel through higher ground, building an embankment over lower ground, or constructing a canal lock (or series of locks) to change the level of the canal. Because of this, these canals are characterized by their meandering course.
Step Determine the depth D and bed width B from values of A & P
Cost of construction including cross drainage works should be minimized. .A shorter length of canal ensures less loss of head due to friction and smaller loss of discharge due to seepage and evaporation, so that additional area may be brought under cultivation. A canal may be aligned as a contour canal, a side slope canal or a ridge canal according to the type of terrain and culturable area. A contour canal irrigate areas only on one side of the canal. Where canal crosses valleys, different types of cross drainage works are required. A side slope canal is aligned at 90 degree to the contours of the region. A watershed or ridge canal irrigate areas on both sides. Cross drainage works are eliminated in case of ridge and side slope. Main canal is generally carried on a contour alignment. Branch and distributaries take off from a canal from or near the points where the canal crosses the watershed. All possible alignments should be studied and the best suited alignment should be selected. Number of rinks and acute curves should be minimized. They should be aligned as far as possible in partial cutting partial filling. Deep cutting should be avoided by comparing the overall cost of alternative alignments.
Options contract on indian derivative marketRitesh Sethi
This PPT is helpful for the student who is doing MBA in finance extreme.
it is just small help from my side in future also i will be uploading these type of PPT'S.
Thank You
Ritesh Sethi
Topics:
1. Reservoir Classification
2. Investigations
3. Selection of Site for Reservoir
4. Zones of Storage
5. Storage Capacity and Yield
6. Mass Inflow Curve & Demand Curve
7. Calculation of Reservoir Capacity
8. Reservoir Sedimentations
9. Life of Reservoir
10. Selection of Dam
Reservoir Planning: Introduction; Investigations for reservoir planning; Selection of site for a reservoir; Zones of storage in a reservoir; Storage capacity and yield; Mass inflow curve and demand curve; Calculation of reservoir capacity for a specified yield from the mass inflow curve; Determination of safe yield from a reservoir of a given capacity; Sediment flow in streams; Life of reservoir; Reservoir sediment control; flood routing. Various types of Spillways and design.
Introduction, Term related to reservoir planning (Yield, Reservoir planning and operation curves, Reservoir storage, Reservoir clearance), Investigation for reservoir planning, Significance of mass curve and demand curves, Applications of mass-curve and demand curves, Fixation of reservoir capacity from annual inflow and outflow, Fixation of reservoir capacity.
A hydraulic structure may be defined as any structure which is designed to handle water in any way
This includes the retention, conveyance, control, regulation and dissipation of the energy of water
Such water handling structures are required in many fields of civil engineering
The principal ones being water supply and conservation, hydroelectric power, irrigation and drainage, navigation, flood control, fish, wildlife service’s and certain aspects of highway engineering. Various equations, based on continuity, energy, and momentum principles, may be used
To calculate the most suitable length, width, shape, elevation and orientation of the structure.
The application of these basic principles to the practical problem of the design of hydraulic structures is called hydraulic design
Designed and constructed for managing and utilizing water resources to the best advantage of the human being and environment
Seepage through canals_seminar presentationRaj Bisen
This Presentation represents Final year seminar presentation on seepage through lined and unlined canal by swamee et al method. submitted to HoD, Government College of Enginneering, Amravati By Raj Bisen.
Canal & canal types with design of channels by dj sir covered kennedy lacey t...Denish Jangid
Canal its types with design of channels by Denish Jangid sir.
covered kennedy lacey theory IS code method with comparison drawbacks.
design steps by kennedy
design steps by lacey
design of canal types of canal trapezoidal shape. Canal Irrigation. Subject-
Water Resources Engineering By Dr.* Denish Jangid Assistant Professor Civil Engineering Department
Canal Classification based on Financial returns
Canal Classification based on Use
Canal Classification based on Size
Cana Masonry work
alluvial soil
Cross regulator
Head regulator
Silt Control device
Silt ejector
Silt excluder
Factor affecting the Canal Alignment
A contour canal is an artificially-dug navigable canal which closely follows the contour line of the land it traverses in order to avoid costly engineering works such as boring a tunnel through higher ground, building an embankment over lower ground, or constructing a canal lock (or series of locks) to change the level of the canal. Because of this, these canals are characterized by their meandering course.
Step Determine the depth D and bed width B from values of A & P
Cost of construction including cross drainage works should be minimized. .A shorter length of canal ensures less loss of head due to friction and smaller loss of discharge due to seepage and evaporation, so that additional area may be brought under cultivation. A canal may be aligned as a contour canal, a side slope canal or a ridge canal according to the type of terrain and culturable area. A contour canal irrigate areas only on one side of the canal. Where canal crosses valleys, different types of cross drainage works are required. A side slope canal is aligned at 90 degree to the contours of the region. A watershed or ridge canal irrigate areas on both sides. Cross drainage works are eliminated in case of ridge and side slope. Main canal is generally carried on a contour alignment. Branch and distributaries take off from a canal from or near the points where the canal crosses the watershed. All possible alignments should be studied and the best suited alignment should be selected. Number of rinks and acute curves should be minimized. They should be aligned as far as possible in partial cutting partial filling. Deep cutting should be avoided by comparing the overall cost of alternative alignments.
Options contract on indian derivative marketRitesh Sethi
This PPT is helpful for the student who is doing MBA in finance extreme.
it is just small help from my side in future also i will be uploading these type of PPT'S.
Thank You
Ritesh Sethi
It contains detailed information about a Gravity Dam........it also conataims the information in brief & pictures giving a clear view of the Gravity Dams...........It also contains formulas with details of their terms.........
Economic Design of Water Tank of Different Shapes With Reference To IS: 3370 ...IJMER
The conventional method of designing water tanks which is working stress method
outlined in the previous version of IS: 3370 1965 is irrational and leads to relatively thicker sections
with a substantial amount of reinforcement. Limit state method which is widely used has been recently
adopted in the new version of IS 3370-2009 concrete structures for storage of liquids – code of
practice. For quick cost prediction of tanks, this study therefore examines the cost effectiveness in terms
of amount of materials and formwork used for Circular, Square and Rectangular overhead water tanks
each of three capacities of 100kl, 150kl, 200kl and draw reasonable inferences on tank’s shape design
effectiveness . Each water tank was designed by Limit State method and then the crack width was
checked by limit state of serviceability IS 3370 (2009). The results have been presented in the form of
graphs and tables and it has been observed that Circular-shaped tank consumed lesser of each
material as compared to Square and Rectangular ones. The amount of formwork required for circular
tank is also less than that for square and rectangular tanks thereby giving Circular-shaped tanks a
more favorable selection over the rectangular and square shaped tanks
Zimmerman, J., B. Schumacher, C. Lutes, B. Cosky, R. Truesdale and B. Schumacher “ORD VI-research duplex and Wheeler Building, Indianapolis- summary of evidence to date: temporal variability in long-term mitigation performance and before mitigation: What causes it?” Presented at AEHS/EPA 2015 workshop on Long-Term Evidence-Based Protection & Sustainability; in Residential, Commercial and Industrial Buildings; San Diego.
In this you will find some of the basic thing regarding the elevated water tank and this is our one of the team project work in college. Hope you will enjoy it....
Causes of Failure in Storage Facilities and Their Supportstheijes
Storage tanks in metallic or plastic forms are meant for storing water or other liquid substances for use either in industrial or domestic applications. This work looks into where failure occurs in metallic storage tanks, how there occur and why they occur. This study was important in other to proffer solutions and recommendations to the causes of failure recorded. The area of study was in Kaduna State, Nigeria, where four storage tanks were examined. The major causes of failure recorded were failure due to corrosion, failure due to malfunction of part, failure due to wrong construction methods among others. With corrosion of parts ranking highest on failure types, it was recommended that anti- corrosive materials like aluminum or stainless steel should be used for constructing storage tanks and their supports and when using mild steel materials it should be well protected using red oxide paint or hydrophobic polyester coatings.
LATERAL STABILITY IMPROVEMENT FOR ELEVATED STEEL WATER STORAGE RESERVOIR IN S...Ishwar Kumbar
In the present study, the attempts are made to study the behavior of hydrodynamic effect (Impact of liquid sloshing) in water full and empty condition on elevated steel water storage reservoir in sever wind and earthquakes zone of India. The analysis is done with Equivalent static method, Response spectrum method and also P-Delta effect with different combination of lateral and horizontal braced supporting frame systems. For modeling and analysis were performed using Etabs Ultimate 17.0.1
ICLR Friday Forum: Lot-level approaches to control urban flood risk (April 21...glennmcgillivray
On March 24, 2017, ICLR conducted a Friday Forum led by Professor Andy Binns and Professor Ed McBean from the University of Guelph. Water damage due to basement flooding results in nearly $2 billion in insured damages every year in Canada. More frequent extreme rainfall events, aging
infrastructure and urbanization continue to exacerbate the economic damages associated with this problem. The risk of basement flooding, which can occur due to overland flow, infiltration, or sewer back-up, is affected by numerous environmental, socio-political, governance and infrastructure-related (both at the municipal and lot-levels) factors. Several approaches at both the lot-level and municipality-level can be implemented to assist in mitigating the risk of basement flooding. These methods include low impact development strategies to reduce run off from entering the sewer system and installation of backwater vaIves to reduce occurrences of basement flooding due to sewer back-up. This seminar will discuss the issue of basement flooding in Canada and explore mitigation technologies that can help protect homes from water damage and reduce risk of basement flooding in cities. Results from recent laboratory and computational investigations into the performance of backwater valves will be presented along with plans for future research on these topics over the next four years.
Prof. Andrew Binns is an Assistant Professor in Water Resources Engineering at the University of Guelph. Andy received his PhD in Civil Engineering from Queen's University in 2012. Andy's research includes topics in the areas of urban flooding and the effects of floods on urban infrastructure, stormwater management and low impact development, and river and stream restoration practices.
Prof. Ed McBean is a Professor of Water Resources Engineering and Canada Research Chair of Water Supply Security at the University of Guelph. Ed received his PhD in Civil Engineering from MIT in 1973. Ed's research includes urban flooding characterization and asset characterization of municipal water infrastructure, and low impact development design and maintenance.
Engineering is the professional art of applying science to the optimum conversion of the resources of nature to benefit man.
The internship at Cochin Shipyard,DMRC and Vytilla helped in bridging the gap between theory and practice and provided practical,field based and real world experience.
This presentation covers an imaginary design of diversion dam in Tarbela dam Pakistan. The design covers all the prospects of dam engineering, from basics dam planning to construction.
This chapter is based on the book Hydraulics of Spillways and Energy Dissipators By Rajnikant M. Khatsuria ,concerned with the general procedure of an overall design. An evaluation of the basic data should be the first step in the preparation of the design. This includes the topography and geology as well as flood hydrography, storage, and release requirements.
SBA & City of Evanston Economic Injury Webinar - 4/1/2020cityofevanston
Stephen Konkle from the Small Business Administration (SBA) presents options for City of Evanston businesses in the wake of the COVID-19 disaster. Includes information on the Economic Injury Disaster Loans (EIDL).
Jennifer Schaus and Associates hosts a complimentary webinar series on The FAR in 2024. Join the webinars on Wednesdays and Fridays at noon, eastern.
Recordings are on YouTube and the company website.
https://www.youtube.com/@jenniferschaus/videos
Russian anarchist and anti-war movement in the third year of full-scale warAntti Rautiainen
Anarchist group ANA Regensburg hosted my online-presentation on 16th of May 2024, in which I discussed tactics of anti-war activism in Russia, and reasons why the anti-war movement has not been able to make an impact to change the course of events yet. Cases of anarchists repressed for anti-war activities are presented, as well as strategies of support for political prisoners, and modest successes in supporting their struggles.
Thumbnail picture is by MediaZona, you may read their report on anti-war arson attacks in Russia here: https://en.zona.media/article/2022/10/13/burn-map
Links:
Autonomous Action
http://Avtonom.org
Anarchist Black Cross Moscow
http://Avtonom.org/abc
Solidarity Zone
https://t.me/solidarity_zone
Memorial
https://memopzk.org/, https://t.me/pzk_memorial
OVD-Info
https://en.ovdinfo.org/antiwar-ovd-info-guide
RosUznik
https://rosuznik.org/
Uznik Online
http://uznikonline.tilda.ws/
Russian Reader
https://therussianreader.com/
ABC Irkutsk
https://abc38.noblogs.org/
Send mail to prisoners from abroad:
http://Prisonmail.online
YouTube: https://youtu.be/c5nSOdU48O8
Spotify: https://podcasters.spotify.com/pod/show/libertarianlifecoach/episodes/Russian-anarchist-and-anti-war-movement-in-the-third-year-of-full-scale-war-e2k8ai4
What is the point of small housing associations.pptxPaul Smith
Given the small scale of housing associations and their relative high cost per home what is the point of them and how do we justify their continued existance
ZGB - The Role of Generative AI in Government transformation.pdfSaeed Al Dhaheri
This keynote was presented during the the 7th edition of the UAE Hackathon 2024. It highlights the role of AI and Generative AI in addressing government transformation to achieve zero government bureaucracy
Understanding the Challenges of Street ChildrenSERUDS INDIA
By raising awareness, providing support, advocating for change, and offering assistance to children in need, individuals can play a crucial role in improving the lives of street children and helping them realize their full potential
Donate Us
https://serudsindia.org/how-individuals-can-support-street-children-in-india/
#donatefororphan, #donateforhomelesschildren, #childeducation, #ngochildeducation, #donateforeducation, #donationforchildeducation, #sponsorforpoorchild, #sponsororphanage #sponsororphanchild, #donation, #education, #charity, #educationforchild, #seruds, #kurnool, #joyhome
This session provides a comprehensive overview of the latest updates to the Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards (commonly known as the Uniform Guidance) outlined in the 2 CFR 200.
With a focus on the 2024 revisions issued by the Office of Management and Budget (OMB), participants will gain insight into the key changes affecting federal grant recipients. The session will delve into critical regulatory updates, providing attendees with the knowledge and tools necessary to navigate and comply with the evolving landscape of federal grant management.
Learning Objectives:
- Understand the rationale behind the 2024 updates to the Uniform Guidance outlined in 2 CFR 200, and their implications for federal grant recipients.
- Identify the key changes and revisions introduced by the Office of Management and Budget (OMB) in the 2024 edition of 2 CFR 200.
- Gain proficiency in applying the updated regulations to ensure compliance with federal grant requirements and avoid potential audit findings.
- Develop strategies for effectively implementing the new guidelines within the grant management processes of their respective organizations, fostering efficiency and accountability in federal grant administration.
Presentation by Jared Jageler, David Adler, Noelia Duchovny, and Evan Herrnstadt, analysts in CBO’s Microeconomic Studies and Health Analysis Divisions, at the Association of Environmental and Resource Economists Summer Conference.
Effects of Extreme Temperatures From Climate Change on the Medicare Populatio...
A3.1 reservoir apr8 2014
1. RESERVOIR PLANNING STUDY:
A COMPREHENSIVE ASSESSMENT OF
EVANSTON’S WATER STORAGE NEEDS
Presentation to City Council
April 8, 2014
2. Reports Completed to Date
• CTL Group’s structural evaluation of 1913 facilities (2010)
• CTL Group’s structural evaluation of 1934 Reservoir and
1948 Settling Basins No. 1 & 2 (2012)
• CDM Smith’s review of CTL Group’s report on 1934
reservior (2013)
• CTL Group’s Inspection of 1934 Reservoir (2013)
• CDM Smith’s 1934 Reservoir Inspection Report (2013)
• Walker Restoration Consultants1934 Reservoir Roof Slab
Report (2013) prepared for Northwestern University
3. Reason for Current Study
• Comprehensive evaluation of several factors:
Finished water storage requirements
Water treatment requirements
Efficient pump operation
Recommendations based on decision criteria:
Industry best management practices
Age and deteriorated condition of existing structures
Life cycle cost for repair and / or replacement
4. Reason for Current Study
• Complete a life cycle cost analysis to weigh
short-term repairs against long-term solutions.
Repairing the reservoir would extend its life by 20
years maximum
Compare long-term financial impacts of building a
new reservoir now or in 20 years
Is it cost-effective to invest millions of dollars
rehabilitating the 1913 and 1923 facilities when the
concrete structures are likely at the end of their
useful life?
5. Existing Condition of Storage Facilities
Evanston’s water storage is provided by five
facilities that must be evaluated together:
Storage Facility
Gross
Storage (MG)
Year of
Construction Condition
West Plant Clearwells 2.4 1913 and 1923 Poor
East Plant Clearwells 2.0 1948 and 1964 Unknown
Finished Water Reservoir 5.0 1934 Poor
South Standpipe 5.0 1984 Good
North Standpipe 7.5 1986 Good
7. 1913 Clearwells Existing Condition
Vertical and horizontal
wall cracks are prevalent
inside the clearwells
8. 1913 Clearwells Existing Condition
Cracking was also found
on the outer clearwell wall
faces and in the filter walls
above the clearwells
9. 1913 Clearwells Existing Condition
“It is CTLgroup’s opinion that the most
reliable method to repair the clearwell cracks and
eliminate infiltration would be to 1) excavate to
expose all roof and wall surfaces, 2) execute full-
thickness crack repairs, and 3) apply a water proof
coating to all exterior surfaces. However, given
the highly-invasive nature of such a repair, it is
questionable whether such measures would be
considered practical”
John J. Roller, CTL Group, registered professional engineer and registered
structural engineer in the state of Illinois.
10. 1934 Reservoir Existing Condition
• CTL Group found
cracks throughout the
underside of the roof
slab in their 2012
inspection
• Walker Restoration
Consultants found
“near disintegration” of
the top 1.5 – 2 inches
of the roof slab in their
2013 inspection
11. 1934 Reservoir Existing Condition
Steel rebar is exposed
and corroded in many
locations on the roof slab
12. 1934 Reservoir Existing Condition
CDM Smith’s 2013 report states of the 1934 Reservoir:
“Given that this concrete structure is about 80 years old,
the rate of deterioration and degradation is expected to be
accelerating for the remainder of its useful life. Under normal
conditions, the average expected useful life of a concrete
structure is about 100 years. This life span can be significantly
reduced if the concrete structure is subject to constant high
humidity and repeated freeze-thaw cycles. This is exactly the
case for the finished water reservoir, especially for the roof slab
of the reservoir. Therefore, …it is probable that the useful life of
the walls and the floor slab will not exceed 100 years.”
Wendell Yang, CDM Smith, registered professional engineer (1983)
and registered structural engineer (1985) in the state of Illinois.
14. Study will consider six alternatives
• 1 – Replace 1934 Reservoir roof and modify to use
entire volume, repair 1913/1923 Clearwells
• 2 – Replace 1934 Reservoir in existing footprint, repair
1913/1923 Clearwells
• 3 – Replace 1934 Reservoir in larger footprint,
decommission 1913/1923 Clearwells
• 4 – Construct a new clearwell on the east side of
Sheridan Road, decommission 1934 Reservoir
• 5 – Construct a new reservoir and pumping station at
Leahy Park
• 6 – Repair 1934 Reservoir roof and modify to use
entire volume, repair 1913/1923 Clearwells
Editor's Notes
We called this a Reservoir Planning Study because the most immediate concern and most expensive component is the 1934 Reservoir. However, this is really a comprehensive study of all of Evanston’s water storage facilities, how they operate together, and how much storage we need based on water system operations and contractual requirements to our wholesale customers.
In 2008 as the filter shop area was being constructed, unexpected damage occurred to the concrete structure.
In 2009 the Department raised concerns about the structural integrity of the concrete in several locations of the treatment plant. Visual inspection of the older filter areas showed signs of concrete failure. Council members toured the plant facility and they were taken to the old filter areas to observe some of the conditions and concerns.
CTL was awarded the first 2 studies based on responses to RFPs 10-75 ($56,250) and RFP 12-158 ($89,000)
CTL’s study expressed immediate concern of the reservoir roof slab, since this was the first time the reservoir had been inspected.
CDM was asked to review the CTL report, confirm the estimated cost to repair, and provide more information about the probable duration of the work and impact to the water treatment processes if the reservoir was taken out of service.
Based on reports and concern that vehicles and snow load on reservoir might cause a problem, NU was advised of situation. They then hired Walker who did inspection in November with report dated December 2013.
CTL re-inspected the reservoir again in 2013 ($20,000) and CDM also participated in the 2013 inspection ($24,262 for both reports and to participate in inspection)
The 2013 inspection revealed that there was no significant deterioration between the 2012 and 2013 inspection.
The overall goal of the department was to complete the structural evaluation of the concrete for the facilities built at different times. The Department had programed funding for concrete repairs in the CIP based on the reports. However, the findings that the 1913 (and assumed 1923) facilities as well as the 1934 facility are in such poor structural condition a comprehensive plan on how to approach the issues based on
At the very least, we are facing an investment of several million dollars to repair the reservoir roof and the 1913/1923 clearwells, as well as to modify the reservoir in order to be able to use the entire volume.
The analysis will determine whether it is cost-effective to invest millions of dollars in structures that are already at or near the end of their useful life, or if there is a more cost-effective option that will provide us with a reservoir that can last another 80-100 years.
Furthermore, we know that IEPA loan and government bond interest rates are favorable now. We do not know if they will still be favorable in 15-20 years. The study will consider the uncertainty in future lending terms and factor that into the life cycle costs.
With the completion of the parking garage, Northwestern will no longer need to use the reservoir top as a parking lot. Plans for that space include anything from tennis courts to a new sports facility.
1913 clearwell walls and bottom slab are known to be in poor condition and the roof slab has not undergone structural testing, but is assumed to be in the same condition as the 1934 reservoir roof slab since it is made of the same non-air-entrained concrete and exposed to the same conditions.
Not only concerned with concrete, but also of valves and design
By wholesale contracts, must equitably apportion the water stored at the plant in the event of emergency
Evanston avg daily demand is 8 MG, therefore should have 16 MG storage (2 days). 12.5 in standpipes but only 3.1 at plant for total of 15.6. And this assumes that the structures are full and that they can be completely drained.
Standpipes are scheduled to be painted in 2014 & 2015. would want them in service prior to doing any work at the plant
The 1913 filtration plant (clearwells and filters) was inspected in 2010 by CTL Group. Significant structural deterioration was found.
The adjacent 1923 filtration plant has not yet been inspected, but it is assumed to be in similar condition since it was constructed of the same non-air-entrained concrete as the 1913 plant.
The 1934 reservoir and 1948 settling basins (No. 1 & No. 2) were inspected in 2012 by CTL Group. The settling basins are in good condition, with only minor defects found. The reservoir walls and floor slab showed deterioration, but nothing immediately concerning given the structure’s age.
The reservoir roof showed significant deterioration in the 2012 inspection. Cores taken from the roof demonstrated that the slab was cracked throughout its entire thickness. The follow-up inspection in 2013 showed little change, meaning the slab should remain safe in the near-term. However, three consultants (CTL, CDM Smith, and Walker) have all recommended extensive rehabilitation or complete replacement of the slab within the next five years to prevent structural failure.
CTL Group conducted a structural inspection of the entire 1913 facility in 2010.
Cores were taken from the walls but not the roof slab. However, the roof slab is only 4” thick and has been subject to the same freeze/thaw damage as the 1934 Reservoir, so it is assumed to be in similar condition.
Significant efflorescence on the outer clearwell wall face (as viewed from the adjacent pipe gallery) indicates moisture is getting through the walls through a significant horizontal crack visible at the top of this patch of efflorescence.
Several vertical wall cracks are visible in the wall of Filter #2 above the clearwells.
Cores were not taken from the roof slabs at the time of this study. Based on the findings at the 1934 Reservoir, it is likely the clearwell roof slab would have the same severe deterioration to the point where major rehabilitation or complete replacement of the roof slab would be warranted.
CTL’s cost estimate for injecting resin into the cracks from the interior of the clearwells, plus other structural repairs needed in the 1913 facility, was almost $1 million in 2010. A major rehabilitation or complete replacement of the clearwell roof slabs would add several million dollars to the cost.
Again, not only concerned about the concrete structure but also the valves, piping and design. The current reservoir has 48” pipe running through it. It does not have any baffling to ensure there is no short circuiting of the water and it has not wet well which would allow for complete draining of the structure.
Conclusion: Repair or replacement of the reservoir roof slab will extend the life of this structure by 20 years at most. At that time we will have no alternative but to construct a new reservoir at increased cost.
Alt. 1 is a temporary fix and would work only if it is determined that no additional storage is needed beyond being able to use the entire 5 MG. A new reservoir/clearwell would be needed within 20 years.
Alt. 2 is for comparison to Alt. 1, to compare the life cycle cost of replacing the reservoir in kind today versus doing it in 15-20 years.
Alt. 3 would require negotiation with NU, though it is certainly a possibility depending on NU’s future plans for North Campus.
Alt. 4 would require the City purchase the Fahner residence at 2437 Sheridan Road, but at the same time perhaps there would be some offsetting concessions by Northwestern in exchange for relinquishing the City’s rights to the current reservoir site.
Alt. 5 is a less ideal scenario from an operational perspective, but would provide much more area to work with in the case we need significantly more storage volume.
Alt. 6 is similar to Alt. 1 except it involves rehab of the roof slab in place rather than complete replacement of the roof slab. This alternative was added to the scope by addendum on February 2, 2014, after the Utilities Dept. received a report from Northwestern’s structural consultant (Walker) proposing the procedure. As with Alt. 1, this is only a temporary fix.