B08_Att_(8)_HAVO_326181_Construction_Phasing_Memo.pdf
PDF 133 KB Posted
- Solicitation number
- 140P2026R0091
About this file
This is a construction phasing memorandum for the HAVO Rainwater Catchment project, dated November 19, 2024, prepared by Martin/Martin Consulting Engineers for project number 23.0544.
The memorandum outlines construction sequencing recommendations for improvements to Ground Catchments 1 and 2, demolition and construction of Buildings 241 and 43, based on water availability analysis. The analysis used precipitation data from 2010 (the lowest rainfall year in the 2007-2022 period), assumed a 20% increase in water demand correlating with increased visitation, and projected six months for Ground Catchment 1 improvements and one year per building for demolition and construction. Key findings indicate that up to two structures can be taken offline simultaneously while maintaining adequate water production year-round, but having all three structures offline simultaneously would result in insufficient raw water production. Construction sequencing can occur in any order provided no more than two structures are offline concurrently, regardless of season. Pre-construction recommendations include installing a new splitter box and 24-inch pipe to Ground Catchment 2, redirecting all rainwater from Buildings 241 and 43 to Ground Catchment 2 before beginning Ground Catchment 1 work, and filling all raw and finished water storage tanks to capacity before taking any structures offline. Additional concurrent construction activities are permitted, including slow sand filter interior improvements, installation of an alternate raw water pump, replacement of the finished water recirculation pump, and exterior tank preparation and painting.
View the file
Other files
Show all 17
On GovTribe
Work with this file
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
To: David Sacamano, PLSA, ALSA - Otak Date: November 19, 2024
From: Justin Meeks, PE Project No.: 23.0544
Copy To: Project Title: HAVO Rainwater Catchment
Construction Phasing - 326181
Re: HAVO Construction Phasing
Construction phasing for the rainwater catchment areas include improvements to Ground Catchments 1 and
2, demolition and construction for Buildings 241 and 43. Based on monthly precipitation data provided by
HAVO staff for the years 2007 to 2022, the months May through September have the lowest rates of rainfall.
Martin/Martin performed water analysis to estimate impacts to the raw water storage of the Park during construction. Water analysis used precipitation data from 2010, which had the lowest annual rainfall during the period provided. Analysis also used a 20% increase in average monthly water use, as calculated from meter data provided by HAVO staff for the years 2018 to 2022. The 20% increase in water use was assumed to correlate with a 20% increase in visitation. The water analysis assumed that improvements to Ground
Catchment 1 would take around six (6) months, and the demolition and construction of the buildings to take one (1) year per building. The analysis was completed using the 2010 low precipitation conditions, 20% increase in demand/visitation, and construction schedule to be conservative.
The analysis predicted that the construction on GC1, Building 241, and 43 can be completed in any order if a single structure is offline at a time. It is predicted that up to two of these structures can be taken offline simultaneously while maintaining sufficient water production throughout construction. It is predicted HAVO can have GC1 be offline at the same time as either of the rainshed buildings or have both buildings under construction simultaneously. Having all three structures offline, the evaluation showed that there would not be enough raw water production and service could not be maintained. The evaluation showed that with only two structures offline simultaneously, water production could be maintained throughout construction regardless of the season when construction commences.
The following recommendations were developed for implementation prior to starting construction, regardless of seasonality or sequencing:
• Install new Splitter box and 24 pipe to GC2
• Direct all rain catchment from Building 241 and Building 43 to GC2 prior to starting construction of
GC1 to minimize pumping between reservoirs and water wasted to drain GC1
• Fill all raw water storage tanks and finished water storage tanks to capacity prior to taking any structures offline to maximize storage
Additional construction items that can occur during any phase of construction that are related to the water treatment process and structures:
• Improvements to Slow Sand Filters interiors one at a time as noted on plans.
• Installation of alternate Raw Water Pump.
• Replacement of Finish Water Recirculation Pump.
• Prep and Paint exterior Tanks as noted on plans.
File details come from the government source that posted it. Updated .