Category

Flood Protection

Green Stormwater Infrastructure article

By | Flood Protection

Last August, the City of Houston’s Chief Recovery Office commissioned a one-year study to identify and recom­mend incentives to encourage the use of green stormwater infrastructure (GSI) in private land develop­ment, leading to economic, social, and environmental benefits as well as resilience.

In the a report, Houston Mayor Sylvester Turner said “While we continue to pursue large-scale projects to reduce flood risk, Hurricane Harvey and other floods have highlighted the necessity to employ a holistic stormwater management approach which integrates green infrastructure into our existing drainage systems.”

GSI is a stormwater management tool that can increase a property’s operating income, provide green amenities for resi­dents and improve storm drainage, creating a win-win situation for owners, residents and the community. The report defines GSI and outlines the potential four incentives with implementa­tion timelines.

GSI designs use multiple techniques to manage stormwater on a property the way it would behave on a greenfield lot, rather than diverting directly to storm drains, reducing the impact of the development on the downstream municipal stormwater infrastructure, especially during heavy rainfall events like Houston has seen over the years. Techniques that capture and reuse stormwater reduce potable water demands from municipal water systems, which can reduce the property’s water costs. Large amounts of energy are required to purify and distribute water at the municipal level, so reductions in water demands can reduce energy consumption as well. Many of these techniques detailed below will be limited to new developments, but some can be applied to existing properties.

GSI Techniques to Manage Stormwater

Bioretention systems, or rain gardens, can slow the rate of stormwater runoff on a property using native vegetation planted on an engineered substructure of mulch, gravel, fabric and an underdrain. The water is captured and filtered through the layers and eventually drains to the municipal stormwater system. Rain gardens provide additional wildlife habitats and improve the visual appeal of the property.

Green roofs take advantage of unused space to create a green space that can capture and use rainwater, as well as add an amenity for residents. The additional structural and drainage design requirements may limit converting existing roofs, but these can be addressed in a new development project.

Permeable pavement allows stormwater to flow through to an underdrain system or below-grade cistern; again, this slows the runoff rather than diverting the runoff directly to municipal stormwater drains like impervious materials. Permeable pay­ments combined with a rainwater harvesting system can increase the volume of water collected and available for reuse.

Rainwater harvesting systems collect water from roofs, park­ing lots, etc. for reuse on the property for irrigation, cooling tower makeup or greywater systems such as flushing toilets. Above ground storage tanks or underground cisterns can be used for the water collection. Filtration, treatment and pump systems will also be required to reuse the water, but the long-term savings in water costs can be significant. Rainwater harvesting systems can be added to existing facilities, but limited available space for large storage tanks may limit their effectiveness.

Soil amendments, urban forestry, and vegetated filter strips are all techniques to slow the stormwater runoff on a property using native vegetation and trees. These techniques can be applied to existing properties and new developments.

The initial cost to design and install GSI systems may be higher than traditional alternatives, however, the operating costs can be lower and provide a positive ROI over time for the owner and reduced expenses for the residents. In addition, four incentive programs have been proposed to offset these costs and encour­age GSI projects. Those are:

  • Integrated GSI Development Rules
  • Property Tax Abatements
  • Award and Recognition Program
  • Increased Permitting Process Certainty and Speed

Based on feedback from developers, current development rules do not promote the use of GSI techniques in new developments. New integrated GSI development rules would incentivize devel­opers to use GSI techniques by allowing an alternative set of rules for permitting that could reduce overall project costs by 2% and site costs by 34%.

Along similar lines, an alternative permitting program could speed up the permitting time and reduce costs. The recommen­dation is for a team review process where stakeholders meet for two to four hours, review the designs, make any required changes and then issue permits immediately after the meeting.

Property tax abatements are the second incentive recommend­ed in the study. By reducing future property taxes, developers can cover some or all of the additional costs related to GSI projects.

A reward and recognition program is another way to incen­tivize GSI projects in Houston, however, without the financial benefits of the other incentives proposed, a recognition program alone is unlikely to motivate developers to use GSI projects.

The report outlines the related stakeholders and a plan for implementation with timelines for all of the incentives proposed. Additionally, it is recommended that multiple incentives are used together to incentivize developers more to use GSI projects. Visit the City of Houston website to see the full report.

Although it’s not covered in the report, another incentive that could potentially be used for GSI on existing properties is Property Accessed Clean Energy funding. PACE is a financial tool that property owners can use to fund projects that reduce water and energy consumption on their property with a long-term assessment against the property with no or little initial capital expense. For more information on PACE, visit the Texas PACE Authority website.

Many of the GSI projects could also earn points toward a LEED certification through the U.S. Green Building Council. For devel­opers already pursuing a LEED certification, GSI related incen­tives may be even more desirable. For more information on LEED, visit the USGBC website.

GSI projects will have a very positive impact on the City of Houston as they increase property value and operating income, improve amenities for residents and improve stormwater drainage for the greater community. As demand for sustainable buildings increases from residents and the incentive programs offset additional costs, we will, hopefully, see it become the stan­dard practice in the not so distant future.

This article was originally published in HAA’s ABODE magazine. Click here to see the original article.

Disaster Preparedness Planning for Hurricane Season

By | Flood Protection

June 1st marks the beginning of Hurricane Season, and the NOAA predicts 2020 will be busier than average.  While many property & facility managers are still working through the building operations changes required due to COVID-19, there are some additional measures to consider in preparation for potential heavy rains and flooding.  The National Weather Service and FEMA have guidelines for the overall planning, so we will highlight a few items specific to water systems in commercial buildings.

Before the Storm

It is critical to regularly perform Preventive Maintenance (PM) on Storm Sump Pump Stations to ensure their performance.  A PM should include a visual inspection of the sump basin, verifying the operation of each pump, and the control panel.  Cougar USA now offers Preventive Maintenance programs on Sump Stations, as well as other water control systems.

During the Storm

If you have an issue during a storm, Cougar USA Technical Support and Service can be reached 24/7 at 832-678-3930.  We help troubleshoot issues over the phone and with our Remote Guidance App that allows us to see what you see in real-time. 

remote guidance

After the Storm

Cougar USA is available 24/7 to assist you.  We have service techs available for site visits and troubleshooting, as well as a fleet of rental Booster Pumps and Sump Pumps ready for install.  We also have a large inventory of replacement sump pumps, control panels, and parts to get you back up and running.

rental pumps

Please contact Cougar USA if you are interested in our Preventive Maintenance programs or other services. 

Overflow and Flood Protection for Break Tanks in Commercial Buildings

By | Flood Protection, Level

Many commercial buildings in Houston have large water storage tanks to meet city plumbing code requirements. These break tanks provide water for fire protection pumps and domestic (potable) water pumps to supply the building. A major concern with break tanks in the building is the potential for flooding due to tank overflow. This is especially critical when the tanks are in a basement level.

In order to maintain a constant water level in the break tank, float style or electronic fill valves and controls must be used. The valves open when the tank level is low, and when the tank level returns to normal they close. With either system, there is a potential for the fill valve to fail in the open position, allowing water into the tank without control.

The Houston Amendments to the Uniform Plumbing Code Table 607.7 has specific guidelines for tank overflow and vent sizing, so in the event of a valve failure, the excess water will flow through the overflow to a floor drain. Especially on a fire tank system with large fill valves, this can be up to 1,000 gallons per minute of water pouring onto the floor of the pump room. Even when properly sized, floor drains may not handle this sudden demand (trash, etc.), and water can flood the pump room.

To avoid this situation all together, Cougar USA recommends shutting off the tank water supply when a critical high level is reached. This requires a control panel, tank-level sensors and an additional valve in the tank supply piping — often called a block valve. The block valve is normally open and only closes in the event of a tank high level.

The Cougar Systems Elite Control Panel and Tank Sensors monitor the tank levels using a pressure sensor and conductivity probes. The High Level Alarm Settings are made on the touchscreen to control at what tank level the block valve will be closed.

There are two styles of valves that can be used for the block valve. The same electronic Cla-Val used for the fill valves can be configured as a block valve. This can be an effective block valve but it must be exercised regularly with water flow through scheduled preventative maintenance (PM) to ensure proper operation of the valve. Without regular PM, there is a high probability the valve will not close in the event of a tank high level due to air on the diaphragm or trash in the tubing or solenoid valve.

Cougar USA recommends the use of a motor-operated butterfly valve for a block valve. The butterfly valve’s ability to perform is substantially less affected by intermittent use because it uses an electric motor to actuate the valve rather than a hydraulic actuator. It can also easily be tested without requiring water flow, and it requires less piping space than a same-sized Cla-Val.

Tank overflow and flooding can be mitigated with a block valve and controls but, with any tank system, the Building Management System should always monitor tank levels and alarms.

For more information or a free building assessment from Cougar USA, contact us here.