Basic sewer plan and Blue Vein Plan.

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Basic drainage plan

What is it

The Basic Sewerage Plan is a hydraulic test of the sewer system against current conditions. The calculation in this Technical Sewerage Plan only examines the operation of the underground system. Where the underground system has insufficient discharge capacity, water problems arise at ground level. The vulnerabilities at that level were made visible in the Climate Stress Tests we presented last fall (see https://dommelvalle i.kaartviewer.nl/?@Climate%20Geldrop-Mierlo).

Why are we making this

A Basic Sewerage PlanBRP) is updated every 10 years. Over the years, many things change about the sewer system. But also the number of connected homes and businesses, and thus the draining surface, changes. Finally, laws and regulations sometimes change as well. The current plan dates from 2011 and is no longer current. We have therefore drawn up a new plan. The starting points for the technical calculations were updated. Hydraulic calculations were then performed in accordance with the Urban Water Knowledge Base of the Rioned Foundation.

What's in

The results of the calculations in the BRP provide insight into the bottlenecks in the sewer system. By combining the data with the climate stress tests and the observations of residents, we can develop well-founded solutions and thus use the available resources efficiently. The report describes a principle solution for bottlenecks. These are not yet mature plans. The outline plans will be worked out in more detail and scheduled in the investment program of the municipal budget.

Summary Contents

The sewer systems of Geldrop and Mierlo are not connected. Therefore, they are treated separately.

The operation of the systems was tested with bui 8 from the Guidelines for Urban Water. A control calculation with shower 10 clearly shows the bottlenecks. However, these are one-dimensional simulations. To (also) visualize the flow over ground level, a 2D simulation was performed. In this way it is clear where the water, after leaving the sewer, flows to. The locations where the water exits do not necessarily correspond with the locations where nuisance occurs. The 2D model therefore mainly provides insight into the consequences of hydraulic overloading.

Geldrop

Most of the sewers in the core of Geldrop consist of mixed sewers. There is also a part executed as separated sewers and a part infiltration sewer, with or without emergency overflow on the mixed system. The mixed system of Geldrop discharges under free fall to the sewer of the Water Board. This takes place at Kervel in the north and at Rielsedijk in the west There are four external overflows and three peripheral facilities in the mixed system of the core of Geldrop.

present. The paved surface area draining into the sewer system is 360 hectares. The dry weather discharge in the system is 494 m3 per hour.

Geldrop drainage areas

From the simulation with shower 8 from the Urban Water Guideline, some clear areas of concern emerge. Especially in the northeast around Sporkehout and surroundings, water on the street is calculated. Furthermore, the locations Bogardeind, Ori, Parallelweg, Gijzenrooiseweg and Bosrand stand out. These locations largely correspond to already known flooding locations. This problem is confirmed with the simulation.

  1. Gaspeldoorn-Mierloseweg
  2. Sporkehout Savings Pot
  3. Lower Brook
  4. Hooge Akker
  5. Parallel Road
  6. Gijzenrooiseweg
  7. Amroth et al.
  8. Ori etc. (measure under project waterlogging sites)
Problem locations Geldrop
Figure 1: Problem locations Geldrop (green=location from complaint reports)

Mierlo

The Mierlo sewer system drains to the RWZI via Luchen sewer pumping station. The various drainage areas eventually discharge via each other's system to the Luchen sewerage pumping station.

The paved surface area draining into the sewer system is 134 hectares. The dry weather discharge in the system is 161 m3 per hour.

Mierlo drainage areas

Based on the above simulations, some locations are considered bottlenecks. On the Map , the WOS locations from the 1D simulation with shower 08 are combined with the water level Map from the 2D simulation. Reports from practice are also included in the consideration of a location as a bottleneck.

  1. Barley et al.
  2. Bekelaar
  3. Bridge Street - Arkweg
  4. Mayor Verheugt Street
  5. Vesper Street-Loeswijk
  6. Center of Mierlo (Dorpsstraat)
  7. Wersakker etc. (measures included in project Water Flood Locations)
  8. Bishop van Mierlostraat . (measures included in project Water Flood Locations)
  9. Heer Dickbierweg (measures included in project Water Flood Locations)
  10. School Street (measures included in project Water Flood Locations)

The 1D results of squall 08 show some water-on-street locations. In general, the system seems to handle this intensity reasonably well. A few locations stand out, including the area around Barley and Bekelaar.

Another location that emerges is Burgemeester Verheugtstraat. In Bisschop van Mierlostraat, water on the street also occurs during shower 08.

Problem locations Mierlo
Figure 2: Problem locations Mierlo (green=location from complaint reports)

Conclusions

Based on the various simulations and analyses, the following measures are recommended:

Geldrop:

  • Install water storage at Gaspeldoorn;
  • Research on Strabrecht college affiliation;
  • Applying grating covers near Gijzenrooiseweg;
  • Further study of connected paved surface Spaarpot and Sporkehout and possible disconnection.
  • Further study of the functioning of the Kervel edge supply and associated overflows;
  • Further study of connected paved surface Amroth and Hooge Akker and possible disconnection.
  • Measures as outlined under the project floodplain locations.

Mierlo:

  • Remove overflow and install new pipe section off private property near Linde;
  • Construct additional outflow lines from BT de Smaale towards the Eindhoven canal;
  • Install additional overflow and connection at BBB Bekelaar;
  • Remove threshold HWA at the Heuvel and separate discharge from the mixed system. Install an extra outflow from the HWA (current mixed) system towards a water buffer to be realized near the Geldropseweg.
  • Fix 'bottlenecks' HWA system from Village Street;
  • Measures as outlined under the project floodplain locations.

The above measures should be examined for feasibility. To this end, a sketch design and cost estimate must be drawn up for each measure. The proposed measures also need to be considered in conjunction with already planned sewer replacements and/or road reconstructions. The measures should be included in an Implementation Plan in which they are planned in concrete terms, if possible in conjunction with other works.

In addition, a design for the new stormwater structure ("blue vein") was produced for both cores in a separate study. See report INFR200439-RAP02 It is recommended that the proposed measures be prioritized in conjunction with the construction of the HWA structure.

Continued

The proposed solutions should be further developed

The report makes several outline proposals to improve the system. These are expected to be viable solutions, although some measurement and calculation work remains to be done. Money also has yet to be appropriated.

Flooding cannot be prevented.

In recent years, we have faced more and more extreme forms of precipitation, heat and drought. It is not that there is more precipitation each year, but it falls in shorter periods of time. The sewer system can never handle this large peak supply. The sewer system has grown over a period of nearly a century to what it is today. It is financially and practically impossible to anticipate changed precipitation conditions very quickly. But by realizing the improvement measures mentioned in the BRP and Blue Vein Plan and the implementation agenda of the Climate Policy, we can achieve an improvement in the long term (15-25 years). It is therefore a long-term issue, and in the coming decades we must continue to take account of flooding during heavy rainfall.

Want to know more?

The report is quite voluminous and contains a lot of technical information. Would you like more information on this? If so, please contact Rob Elemans or Bart te Walvaart of the Space Department. You can reach them at telephone number 0404-2893893.

Blue Vein Plan

What is it

The Blue Vein Plan is a long-term vision for dealing with stormwater and also an outline plan for constructing stormwater systems. It provides a vision of the final design of the stormwater system as it should look.

Why are we making this

In the past, many stormwater sewers have been installed. However, this was not based on a plan. The basic plan now developed serves as a guide for future sewer improvements. In this way, the resources available to us when constructing stormwater sewers are used efficiently. But in this way we can also better combat rainwater flooding in the longer term.

In 2016, the college adopted the "2016 Stormwater Vision." This precursor to the Blue Vein Plan dealt primarily with addressing then-known flooding locations. This information is still current. But with a better understanding of the spatial causes of flooding during heavy rainfall, we can now also foresee new bottlenecks, better understand existing ones and address problems more effectively. This makes the plan a building block for the implementation agenda of the climate adaptation policy. For our planners, it is a guide for preparing sewer replacements.

By minimizing flooding during heavy rainfall, we can maintain the quality of the living environment. We do this by disconnecting rainwater from the mixed sewer system and enlarging sewer pipe diameters. The Blue Vein Plan aims to provide a vision and concrete optimization for the redistribution of stormwater within the municipality. In outline, this involves draining water from nuisance locations and transporting it to dry locations or locations with additional collection capacity. In the BRP , this vision was checked for proper functioning through a hydraulic calculation.

What's in

The report describes a principle solution to bottlenecks. These are not yet mature plans. The sketch designs will be further elaborated and scheduled on the investment program of the municipal budget.

Summary Contents

General

Both in Geldrop and Mierlo there are several possibilities to set up a robust stormwater system. The proposed measures in Chapter 4 are necessary to achieve a good stormwater structure. The main structure consists of a few continuous rainwater pipes with a robust cross-section. These pipes are projected in some roads with sufficient space for a separate sewer system. Preferably a structure with north-south and east-west connections. The adjacent neighborhoods can eventually be connected to this main structure. A HWA system must then be designed for each neighborhood on the basis of the already present main structure.

This blue vein plan is primarily a practical plan based on the existing HWA pipes. Based on these pipes, proposals have been made for a continuous rainwater structure. The available space in the public area was also considered and search areas were indicated for the temporary buffering of excess rainwater. Some of these search areas are privately owned and will require early consultation with the landowner to discuss options. Opportunities for multiple land uses involving underground water storage, while costly, are common today.

Notwithstanding the above, an important principle is that rainwater should preferably be processed at the place where it falls. So long transport pipes to a location with a water buffer are avoided as much as possible. However, much space in the public area to process the water on site is not available. Encouraging private individuals to disconnect makes a lot of sense, only the enforcement of private facilities remains difficult.

Some of the proposed measures require longer preparation time, others can be implemented in the short term or preparation can begin. However, it is important to actually begin preparation.

According to the model calculations and given the flooding complaints of recent times, the water systems of both cores are prone to flooding in many locations. Therefore, the main conclusion and recommendation is that measures are needed and that club water management is leading in this. This Blue Vein Plan is guiding in this regard. Measures at street level should be further elaborated and tested against the Blue Vein Plan. Good cooperation between water management and work preparation is essential here.

Measures

The plan proposes a large number of measures. In the maps below they are roughly drawn. The number corresponds to the table. The blue lines show the present stormwater sewers.

Blue Vein Plan Mierlo
Figure 3: Blue Vein Plan Mierlo
Blue Vein Plan Geldrop-East
Figure 4: Blue Vein Plan Geldrop-East.
Blue Vein Plan Geldrop-West
Figure 5: Blue Vein Plan Geldrop-West.
Measure table Blue Vein Plan
Figure 6: Blue Vein Plan measures table.

Other recommendations

Traffic calming measures:

  • Thresholds and plateaus can form an obstacle to above-ground stormwater runoff. It is recommended that traffic calming measures be carried out in such a way that it no longer forms an obstacle to stormwater runoff, for example by applying a so-called "thumbtack.

Building levels and plot heights

  • Heights must be established in the plan design, also record them and control them during realization. Agreements between water management and building/living is very important. This prevents problems in the future. A low position is sensitive to water flooding from the sewer system and to stormwater runoff.

HWA sewer and connections to mixed sewer

  • Underground connections between a HWA sewer (or IT sewer) and mixed sewer are not (always) desirable. An HWA sewer should always be provided with an escape, for example, to open water or a lowered green area.

Venting of sewer systems

  • When disconnecting, the venting of the existing mixed sewer system is a major concern. In addition, the venting of an HWA system can easily be solved by applying grate covers. It is recommended that the planning process include such points in a project plan.

Main structures ditches vs maintenance

  • The inventory found that ditches are not connected, or culverts are full of sand and leaves. Advice is to maintain and/or check these periodically.

Plan design, principles and review options

  • It has been found that some situations have been realized over time that are undesirable from a management point of view. Advice is to find or organize alignment in the planning process with starting points and review options, through a project memo and a transfer checklist.
  • Looking to the future, it is important that new HWA systems be designed in consultation between the water management department and project preparation for larger works. The principles should be drawn up by water management staff as the main stakeholder and passed along to the work planners. Applying a robust escape is essential in this regard.
  • In projects where a HWA system is constructed, it is recommended that the front of existing homes also be disconnected and connected to the HWA system.
  • When disconnecting the road pavement, care must be taken to ensure that the venting for the mixed system through the gullies has been eliminated. Additional venting through the inspection manhole covers is recommended.
  • When a road/area is reconstructed, a stormwater vision for the affected area should also be prepared to ensure that a properly functioning HWA system is created over time. The Blue Vein Plan serves as the basis for this stormwater vision.

Continued

The proposed solutions should be further developed

The report makes several outline proposals to improve the system. These are expected to be feasible solutions, although some measurement and calculation work remains to be done. Money also has yet to be appropriated.

Flooding cannot be prevented.

In recent years, we have faced more and more extreme forms of precipitation, heat and drought. It is not that there is more precipitation each year, but it falls in shorter periods of time. The sewer system can never handle this large peak supply. The sewer system has grown over a period of nearly a century to what it is today. It is financially and practically impossible to anticipate changed precipitation conditions very quickly. But by realizing the improvement measures mentioned in the BRP and Blue Vein Plan and the implementation agenda of the Climate Policy, we can achieve an improvement in the long term (15-25 years). It is therefore a long-term issue, and in the coming decades we must continue to take account of flooding during heavy rainfall.

Want to know more?

The report is quite voluminous and contains a lot of technical information. Would you like more information on this? If so, please contact Rob Elemans or Bart te Walvaart of the Space Department. You can reach them at telephone number 0404-2893893.